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Papers for Tuesday, Oct 24 2023

Papers with local authors

Qingmin Zhang, Weilin Teng, Dong Li, Jun Dai, Yanjie Zhang

11 pages, 9 figures, accepted for publication by ApJ

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Paper 22 — arXiv:2310.14010
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Paper 22 — arXiv:2310.14010

Hot channels (HCs) are prevalent in the solar corona and play a critical role in driving flares and CMEs. In this paper, we estimate the energy contents of an X1.4 eruptive flare with a fast CME generated by a HC eruption on 2011 September 22. Originating from NOAA AR11302, the HC is the most dramatic feature in 131 and 94 {\AA} images observed by SDO/AIA. The flare is simultaneously observed by SDO/AIA, RHESSI, and STEREO-B/EUVI. The CME is simultaneously detected by the white-light coronagraphs of SOHO/LASCO and STEREO-B/COR1. Using multiwavelength and multiview observations of the eruption, various energy components of the HC, flare, and CME are calculated. The thermal and kinetic energies of the HC are (1.77$\pm$0.61)$\times10^{30}$ erg and (2.90$\pm$0.79)$\times10^{30}$ erg, respectively. The peak thermal energy of the flare and total radiative loss of SXR-emitting plasma are (1.63$\pm$0.04)$\times10^{31}$ erg and (1.03$-$1.31)$\times10^{31}$ erg, respectively. The ratio between the thermal energies of HC and flare is 0.11$\pm$0.03, suggesting that thermal energy of the HC is not negligible. The kinetic and potential energies of the CME are (3.43$\pm$0.94)$\times10^{31}$ erg and (2.66$\pm$0.49)$\times10^{30}$ erg, yielding a total energy of (3.69$\pm$0.98)$\times10^{31}$ erg for the CME. Continuous heating of the HC is required to balance the rapid cooling by heat conduction, which probably originate from intermittent magnetic reconnection at the flare current sheet. Our investigation may provide insight into the buildup, release, and conversion of energies in large-scale solar eruptions.

Yu Pan, Jingwang Diao, Jing-Zhao Qi, Jin Li, Shuo Cao, Qing-Quan Jiang

This article has been accepted by Astronomy & Astrophysics

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Paper 61 — arXiv:2310.14723
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Paper 61 — arXiv:2310.14723

The determination of the spatial geometry of the universe plays an important role in modern cosmology. Any deviation from the cosmic curvature $\Omega_K=0$ would have a profound impact on the primordial inflation paradigm and fundamental physics. In this paper, we carry out a systematic study of the prospect of measuring cosmic curvature with the inspiral signal of supermassive black hole binaries (SMBHBs) that could be detected with TianQin. The study is based on a cosmological-model-independent method that extended the application of gravitational wave (GW) standard sirens in cosmology. By comparing the distances from future simulated GW events and simulated $H(z)$ data, we evaluate if TianQin would produce robust constraints on the cosmic curvature parameter $\Omega_{k}$. More specifically, we consider 3-yr to 10-yr observations of supermassive black hole binaries with total masses ranging from $10^{3}M_\odot$ to $10^{7}M_\odot$. Our results show that in the future, with the synergy of 10-yr high-quality observations, we can tightly constrain the curvature parameter at the level of $1\sigma$ $\Omega_k=-0.002\pm0.061$. Moreover, our findings indicate that the total mass of SMBHB does influence the estimation of cosmic curvature, implied by the analysis performed on different subsamples of gravitational wave data. Therefore, TianQin is expected to provide a powerful and competitive probe of the spatial geometry of the universe, compared to future spaced-based detectors such as DECIGO.

Marylou Fournier-Tondreau, Ryan J. MacDonald, Michael Radica, David Lafrenière, Luis Welbanks, Caroline Piaulet, Louis-Philippe Coulombe, Romain Allart, Kim Morel, Étienne Artigau, Loïc Albert, Olivia Lim, René Doyon, Björn Benneke, Jason F. Rowe, Antoine Darveau-Bernier, Nicolas B. Cowan, Nikole K. Lewis, Neil James Cook, Laura Flagg, Frédéric Genest, Stefan Pelletier, Doug Johnstone, Lisa Dang, Lisa Kaltenegger, Jake Taylor, Jake D. Turner
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Paper 76 — arXiv:2310.14950
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Paper 76 — arXiv:2310.14950

The JWST Early Release Observations (ERO) included a NIRISS/SOSS (0.6-2.8$\,\mu$m) transit of the $\sim\,$850$\,$K Saturn-mass exoplanet HAT-P-18$\,$b. Initial analysis of these data reported detections of water, escaping helium, and haze. However, active K dwarfs like HAT-P-18 possess surface heterogeneities $-$ starspots and faculae $-$ that can complicate the interpretation of transmission spectra, and indeed, a spot-crossing event is present in HAT-P-18$\,$b's NIRISS/SOSS light curves. Here, we present an extensive reanalysis and interpretation of the JWST ERO transmission spectrum of HAT-P-18$\,$b, as well as HST/WFC3 and $\textit{Spitzer}$/IRAC transit observations. We detect H$_2$O (12.5$\,\sigma$), CO$_2$ (7.3$\,\sigma$), a cloud deck (7.4$\,\sigma$), and unocculted starspots (5.8$\,\sigma$), alongside hints of Na (2.7$\,\sigma$). We do not detect the previously reported CH$_4$ ($\log$ CH$_4$ $<$ -6 to 2$\,\sigma$). We obtain excellent agreement between three independent retrieval codes, which find a sub-solar H$_2$O abundance ($\log$ H$_2$O $\approx -4.4 \pm 0.3$). However, the inferred CO$_2$ abundance ($\log$ CO$_2$ $\approx -4.8 \pm 0.4$) is significantly super-solar and requires further investigation into its origin. We also introduce new stellar heterogeneity considerations by fitting for the active regions' surface gravities $-$ a proxy for the effects of magnetic pressure. Finally, we compare our JWST inferences to those from HST/WFC3 and $\textit{Spitzer}$/IRAC. Our results highlight the exceptional promise of simultaneous planetary atmosphere and stellar heterogeneity constraints in the era of JWST and demonstrate that JWST transmission spectra may warrant more complex treatments of the transit light source effect.

B. A. Nicholson, S. Aigrain, N. L. Eisner, M. Cretignier, O. Barragán, L. Kaye, J. Taylor, J. Owen, A. Mortier, L. Affer, W. Boschin, A. Collier Cameron, M. Damasso, L. Di Fabrizio, V. DiTomasso, X. Dumusque, A. Gehdina, A. Harutyunyan, D. W. Latham, M. Lopez-Morales, V. Lorenzi, A. F. Martínez Fiorenzano, E. Molinari, M. Pedani, M. Pinamonti, A. Sozzetti, K. Rice

Submitted for review to the Monthly Notices of the Royal Astronomical Society. 13 pages, 16 figures

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Paper 85 — arXiv:2310.15068
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Paper 85 — arXiv:2310.15068

We present the characterisation of the two transiting planets around HD 152843 (TOI 2319, TIC 349488688) using an intensive campaign of HARPS-N radial velocities, and two sectors of TESS data. These data reveal a unique and fascinating system: HD 152843 b and c have near equal masses of around 9 M$_\oplus$ but differing radii of $3.05 \pm 0.11$ R$_\oplus$ and $5.94^{+0.18}_{-0.16}$ R$_\oplus$ , respectively, and orbital periods of $11.62071^{+9.6e-05}_{-0.000106}$ days and $19.502104^{+7.4e-05}_{-8.5e-05}$ days. This indicates that HD 152843 c is in the lowest fifth percentile in density of the known exoplanet population, and has the longest orbital period among these low density planets. Further, HD 152843 c's radius places it in the Saturn valley, the observed lack of planets larger than Neptune, but smaller than Saturn. The orbital periods of these planets indicate they are near a 5:3 mean motion resonance, indicating the possibility of transit timing variations, and hints at the possibility of interaction with a third planet at some point in the evolution of this system. Further, the brightness of the host star and the low density of HD 152843 c make it a key target for atmospheric characterisation.

Mallory Harris, Diana Dragomir, Ismael Mireles, Karen A. Collins, Solène Ulmer-Moll, Steve B. Howell, Keivan G. Stassun, George Zhou, Carl Ziegler, François Bouchy, César Briceño, David Charbonneau, Kevin I. Collins, Gábor Fűűrész, Natalia M. Guerrero, Jon M. Jenkins, Eric L. N. Jensen, Martti H. K. Kristiansen, Nicholas Law, Monika Lendl, Andrew W. Mann, Hugh P. Osborn, Samuel N. Quinn, George R. Ricker, Richard P. Schwarz, Sara Seager, Eric B. Ting, Roland Vanderspek, David Watanabe, Joshua N. Winn

18 pages, 6 figures, Accepted by the Astrophysical Journal Letters

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Paper 87 — arXiv:2310.15118
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Paper 87 — arXiv:2310.15118

We report the discovery of two TESS sub-Neptunes orbiting the early M dwarf TOI-904 (TIC 261257684). Both exoplanets, TOI-904 b and c, were initially observed in TESS sector 12 with twin sizes of 2.49R$_\oplus$ and 2.31R$_\oplus$, respectively. Through observations in five additional sectors in the TESS primary mission and the first and second extended missions, the orbital periods of both planets were measured to be 10.887$\pm$0.001 and 83.999$\pm$0.001 days, respectively. Reconnaissance radial velocity measurements (taken with EULER/CORALIE) and high resolution speckle imaging with adaptive optics (obtained from SOAR/HRCAM and Gemini South/ZORRO) show no evidence of an eclipsing binary or a nearby companion, which together with the low false positive probabilities calculated with the statistical validation software TRICERATOPS establish the planetary nature of these candidates. The outer planet, TOI-904 c, is the longest-period M dwarf exoplanet found by TESS, with an estimated equilibrium temperature of 217K. As the three other validated planets with comparable host stars and orbital periods were observed by Kepler around much dimmer stars (J$_{mag}$ $>$ 12), TOI-904 c, orbiting a brighter star (J$_{mag}$ $=$ 9.6), is the coldest M dwarf planet easily accessible for atmospheric follow-up. Future mass measurements and transmission spectroscopy of the similar sized planets in this system could determine whether they are also similar in density and composition, suggesting a common formation pathway, or whether they have distinct origins.

All other papers

A. Afruni, S. Lopez, P. Anshul, N. Tejos, P. Noterdaeme, T. A. M. Berg, C. Ledoux, M. Solimano, J. Gonzalez-Lopez, M. Gronke, F. Barrientos, E. J. Johnston

19 pages, 13 figures, accepted for publication in A&A

One of the biggest puzzles regarding the circumgalactic medium (CGM) is the structure of its cool ($T\sim10^4$ K) gas phase. While the kinematics of quasar absorption systems suggests the CGM is composed of a population of different clouds, constraining the clouds' extent and spatial distribution has proven challenging, both from the theoretical and observational points of view. In this work we study the spatial structure of the $z\sim 1$ CGM with unprecedented detail via resolved spectroscopy of giant gravitational arcs. We put together a sample of Mg II$\lambda\lambda 2796,2803$ detections obtained with VLT/MUSE in 91 spatially independent and contiguous sight-lines toward 3 arcs, each probing an isolated star-forming galaxy believed to be detected in absorption. We constrain the coherence scale of this gas ($C_{\rm{length}}$), which represents the spatial scale over which the Mg II equivalent width (EW) remains constant, by comparing EW variations measured across all sight-lines with empirical models. We find $1.4 <C_{\rm{length}}/\rm{kpc} <7.8$ (95% confidence). This measurement, of unprecedented accuracy, represents the scale over which the cool gas tends to cluster in separate structures. We argue that, if $C_{\rm{length}}$ is a universal property of the CGM, it needs to be reproduced by current and future theoretical models in order to understand the exact role of this medium in galaxy evolution.

Ludwig M. Böss, Klaus Dolag, Ulrich P. Steinwandel, Elena Hernández-Martínez, Benjamin Seidel, Jenny G. Sorce

23 pages, 12 figures, submitted to A&A. Comments welcome!

Aims: Detecting diffuse synchrotron emission from the cosmic web is still a challenge for current radio telescopes. We aim to make predictions for the detectability of cosmic web filaments from simulations. Methods: We present the first cosmological MHD simulation of a 500 $h^{-1} c$Mpc volume with an on-the-fly spectral cosmic ray (CR) model. This allows us to follow the evolution of populations of CR electrons and protons within every resolution element of the simulation. We model CR injection at shocks, while accounting for adiabatic changes to the CR population and high energy loss processes of electrons. The synchrotron emission is then calculated from the aged electron population, using the simulated magnetic field, as well as different models for origin and amplification of magnetic fields. We use constrained initial conditions, which closely resemble the local Universe and compare the results of the cosmological volume to zoom-in simulation of the Coma cluster, to study the impact of resolution and turbulent re-acceleration of CRs on the results. Results: We find consistent injection of CRs at accretion shocks onto cosmic web filaments and galaxy clusters. This leads to diffuse emission from filaments of the order $S_\nu \approx 0.1 \: \mu$Jy beam$^{-1}$ for a potential LOFAR observation at 144 MHz, when assuming the most optimistic magnetic field model and the inclusion of an on-the-fly treatment of re-acceleration of electrons by turbulence. The flux can be increased by up-to two orders of magnitude for different choices of CR injection parameters. This can bring the flux within a factor of 10 of the current limits for direct detection. We find a spectral index of the simulated synchrotron emission from filaments of {\alpha} {\approx} 1.0 - 1.5.

Stuart L. Shapiro

10 pages, no figs, to be published in Phys. Rev. D

We consider the steady-state density and velocity dispersion profiles of collisionless matter around a Schwarzschild black hole (BH) and its associated rate of accretion onto the BH. We treat matter, which could be stars or dark matter particles, whose orbits are {\it unbound} to the BH, but still governed by its gravitational field. We consider two opposite spatial geometries for the matter distributions: an infinite, 3D cluster and a 2D razor-thin disk, both with zero net angular momentum. We demonstrate that the results depend critically on the adopted geometry, even in the absence of angular momentum. We adopt a simple monoenergetic, isotropic, phase-space distribution function for the matter as a convenient example to illustrate this dependence. The effect of breaking strict isotropy by incorporating an unreplenished loss cone due to BH capture of low-angular momentum matter is also considered. Calculations are all analytic and performed in full general relativity, though key results are also evaluated in the Newtonian limit. We consider one application to show that the rate of BH accretion from an ambient cluster can be significantly less than that from a thin disk to which it may collapse, although both rates are considerably smaller than Bondi accretion for a (collisional) fluid with a similar asymptotic particle density and velocity dispersion (i.e., sound speed).

D. J. Watts, U. Fuskeland, R. Aurlien, A. Basyrov, L. A. Bianchi, M. Brilenkov, H. K. Eriksen, K. S. F. Fornazier, M. Galloway, E. Gjerløw, B. Hensley, L. T. Hergt, D. Herman, H. Ihle, K. Lee, J. G. S. Lunde, S. K. Nerval, M. San, N. O. Stutzer, H. Thommesen, I. K. Wehus

15 pages, 15 figures, submitted to A&A

We present the first model of full-sky polarized synchrotron emission that is derived from all WMAP and Planck LFI frequency maps. The basis of this analysis is the set of end-to-end reprocessed Cosmoglobe Data Release 1 sky maps presented in a companion paper, which have significantly lower instrumental systematics than the legacy products from each experiment. We find that the resulting polarized synchrotron amplitude map has an average noise rms of $3.2\,\mathrm{\mu K}$ at 30 GHz and $2^{\circ}$ FWHM, which is 30% lower than the recently released BeyondPlanck model that included only LFI+WMAP Ka-V data, and 29% lower than the WMAP K-band map alone. The mean $B$-to-$E$ power spectrum ratio is $0.40\pm0.02$, with amplitudes consistent with those measured previously by Planck and QUIJOTE. Assuming a power law model for the synchrotron spectral energy distribution, and using the $T$--$T$ plot method, we find a full-sky inverse noise-variance weighted mean of $\beta_{\mathrm{s}}=-3.07\pm0.07$ between Cosmoglobe DR1 K-band and 30 GHz, in good agreement with previous estimates. In summary, the novel Cosmoglobe DR1 synchrotron model is both more sensitive and systematically cleaner than similar previous models, and it has a more complete error description that is defined by a set of Monte Carlo posterior samples. We believe that these products are preferable over previous Planck and WMAP products for all synchrotron-related scientific applications, including simulation, forecasting and component separation.

Lu Shen, Casey Papovich, Jasleen Matharu, Nor Pirzkal, Weida Hu, Bren E. Backhaus, Micaela B. Bagley, Yingjie Cheng, Nikko J. Cleri, Steven L. Finkelstein, Marc Huertas-Company, Mauro Giavalisco, Norman A. Grogin, Intae Jung, Jeyhan S. Kartaltepe, Anton M. Koekemoer, Jennifer M. Lotz, Michael V. Maseda, Pablo G. Pérez-González, Barry Rothberg, Raymond C. Simons, Sandro Tacchella, Christina C. Williams, L. Y. Aaron Yung

22 pages, 11 figures

We study the H$\alpha$ equivalent width, EW(H$\alpha$), maps of 19 galaxies at $0.6 < z < 2.2$ in the Hubble Ultra Deep Field (HUDF) derived from NIRISS slitless spectroscopy as part of the Next Generation Deep Extragalactic Exploratory Public (NGDEEP) Survey. Our galaxies mostly lie on the star-formation main sequence with a stellar mass range of $\mathrm{10^9 - 10^{11} M_\odot}$, and are therefore characteristic of "typical" star-forming galaxies at these redshifts. Leveraging deep HST and JWST broad-band images, spanning 0.4-4 $\mu$m, we perform spatially-resolved fitting of the spectral energy distributions (SEDs) for these galaxies and construct specific star formation rate (sSFR) and stellar-mass-weighted age maps. We compare these to the EW(H$\alpha$) maps with a spatial resolution of $\sim$1 kpc. The pixel-to-pixel EW(H$\alpha$) increases with increasing sSFR and with decreasing age, with the average trend slightly different from the relations derived from integrated fluxes of galaxies from the literature. Quantifying the radial profiles of EW(H$\alpha$), sSFR, and age, the majority (84%) of galaxies show positive EW(H$\alpha$) gradients, positive sSFR gradients, and negative age gradients, in line with the the inside-out quenching scenario. A few galaxies (16%) show inverse (and flat) trends possibly due to merging or starbursts. Comparing the distributions of EW(H$\alpha$) and sSFR to the star formation history models as a function of galactocentric radius, the central region of galaxies (e.g., their bulges) have experienced, at least one, rapid star-formation episodes, which leads to the formation of bulge, while their outer regions (e.g., disks) grow in a more steady-state. These results demonstrate the ability to study resolved star formation in distant galaxies with JWST NIRISS.

M. S. Oey (U. Michigan), Amit N. Sawant, Ashkbiz Danehkar, Sergiy Silich, Linda J. Smith, Jens Melinder, Claus Leitherer, Matthew Hayes, Anne E. Jaskot, Daniela Calzetti, You-Hua Chu, Bethan L. James, Goeran Oestlin

13 pages, 8 figures. Accepted to ApJ Letters

We use the Hubble Space Telescope ACS camera to obtain the first spatially resolved, nebular imaging in the light of C IV 1548,1551 by using the F150LP and F165LP filters. These observations of the local starburst Mrk 71 in NGC 2366 show emission apparently originating within the interior cavity around the dominant super star cluster (SSC), Knot A. Together with imaging in He II 4686 and supporting STIS FUV spectroscopy, the morphology and intensity of the C IV nebular surface brightness and the C IV / He II ratio map provide direct evidence that the mechanical feedback is likely dominated by catastrophic radiative cooling, which strongly disrupts adiabatic superbubble evolution. The implied extreme mass loading and low kinetic efficiency of the cluster wind are reasonably consistent with the wind energy budget, which is probably enhanced by radiation pressure. In contrast, the Knot B SSC lies within a well-defined superbubble with associated soft X-rays and He II 1640 emission, which are signatures of adiabatic, energy-driven feedback from a supernova-driven outflow. This system lacks clear evidence of C IV from the limb-brightened shell, as expected for this model, but the observations may not be deep enough to confirm its presence. We also detect a small C IV-emitting object that is likely an embedded compact H II region. Its C IV emission may indicate the presence of very massive stars (> 100 M_sun) or strongly pressure-confined stellar feedback.

Diego Garcia Lambas, Frode K. Hansen, Facundo Toscano, Heliana E. Luparello, Ezequiel F. Boero

6 pages, 8 figures. Accepted for publication in A&A

The non-Gaussian Cold Spot (CS) surrounded by its hot ring is one of the most striking features of the CMB. It has been speculated that either new physics or ISW effect induced by the presence of a cosmic void at high redshift can account for the observations. Here we investigate if the systematic decrease in CMB temperature in the neighbourhood of nearby galaxies may create such a strong temperature depression. In particular, we note that the Eridanus supergroup and its neighbouring groups, is in the CS area. Our goal is to analyse observational galaxy data to characterise the neighbourhood of the CS, explore the properties of these galaxies and thereby make a prediction of the CMB temperature decrement in this region. We use the Planck SMICA maps and the galaxy catalogues 2MRS, 6dF and HIPASS as foreground tracers. We apply mean temperature profiles to model the temperature decrement from the galaxies in the CS area. Even after correcting for the mean low temperature of the CS region, we find that the temperature decrement around galaxies is significantly stronger than the mean decrement in other parts of the sky. We discuss whether this could be attributed to the fact that the CS area coincides with one of the regions populated by the most HI deficient galaxies. Modelling the foreground temperature profile, we find a particularly strong temperature decrement due to the presence of the late-type overabundant largest group complex in the nearby universe. A CS shape, which to a large degree overlaps with the CMB CS, is observed. We conclude that the coincidence of the only nearby spiral rich group complex located in the CS region, and the success of the modelling performed, adds strong evidence to the existence of a local extragalactic foreground which could account for the observed temperature depression, alleviating the tension with an otherwise Gaussian field expected in the CMB.

Tejas Prasanna, Todd A. Thompson, Christopher Hirata

18 pages, 16 figures

After a successful supernova, a proto-neutron star (PNS) cools by emitting neutrinos on $\sim 1-100$ s timescales. Provided that there are neutrino emission `hot-spots' or `cold-spots' on the surface of the rotating PNS, we can expect a periodic modulation in the number of neutrinos observable by detectors. We show that Fourier transform techniques can be used to determine the frequency of rotation of the PNS from the neutrino arrival times. Provided there is no spindown, a 1-parameter Discrete Fourier Transform (DFT) is sufficient to determine the spin period of the PNS. If the PNS is born as a magnetar with polar magnetic field strength $B_0 \gtrsim 10^{15}$ G and is `slowly' rotating with an initial spin period $\gtrsim 100$ ms, then it can spin down to periods of the order of seconds during the cooling phase. We propose a modified DFT technique with three parameters to detect spindown. Due to lack of neutrino data from a nearby supernova except the $\sim20$ neutrinos detected from SN1987A, we use toy models and one physically motivated modulating function to generate neutrino arrival times. We use the false alarm rate (FAR) to quantify the significance of the Fourier power spectrum peaks. We show that PNS rotation and spindown are detected with $\rm FAR<2\%$ ($2\sigma$) for periodic signal content $\rm M\gtrsim 13-15\%$ if $5\times 10^{3}$ neutrinos are detected in 3 s and with $\rm FAR<1\%$ for $\rm M\geq 5\%$ if $5\times 10^{4}$ neutrinos are detected in 3 s. Since we can expect $\sim 10^{4}-10^{5}$ neutrino detections from a supernova at 10 kpc, detection of PNS rotation and spindown is possible using the neutrinos from the next Galactic supernova.

J. A. Kropotina, A. A. Petrukovich, O. M. Chugunova, A. M. Bykov

11 pages, 10 figures

We directly compare hybrid kinetic simulations and in situ observations of a high Mach number high-$\beta$ shock in the Solar wind. We launch virtual probes to demonstrate that the model quantitatively reproduces the observations. The observed wave properties are caused by the ion Weibel instability in the shock foot. Parameters of reflected ions in the shock foot are extracted from simulations, and their coordinate dependencies are linearly approximated. These approximations could be used in analytical models. Due to strong magnetic variations at ramp the reflected ions density can be locally very high (nearly that of the incoming flow), which makes favourable conditions for the instability.

V. Borka Jovanović, D. Borka, P. Jovanović

9 pages, 5 figures. Accepted for publication in Contrib. Astron. Obs. Skalnate Pleso (Invited lecture at V Meeting on Astrophysical Spectroscopy - A&M DATA 2023)

Here we investigate the giant radio galaxy DA 240, which is a FR II source. Specifically, we investigate its flux density, as well as the spectral index distribution. For that purpose, we used publicly available data for the source: Leahy's atlas of double radio-sources and NASA/IPAC Extragalactic Database (NED). We used observations at 326 MHz (92 cm) and at 608 MHz (49 cm) and obtained spectral index distributions between 326 and 608 MHz. For the first time we give spectral index map for these frequencies. We found that the synchrotron radiation is the dominant radiation mechanism over most of the area of DA 240, and also investigated the mechanism of radiation at some characteristic points, namely its core and the hotspots. The results of this study will be helpful for understanding the evolutionary process of the DA 240 radio source.

J.A. Posligua, T. Heibges, H. Wistrand, C. Guépin, M.H. Reno, T. Venters (for the JEM-EUSO Collaboration)

10 pages, 6 figures, ICRC2023 Conference Proceedings

Very-high-energy neutrinos can be observed by detecting air shower signals. Detection of transient target of opportunity (ToO) neutrino sources is part of a broader multimessenger program. The Extreme Universe Space Observatory on a Super Pressure Balloon 2 (EUSO-SPB2) Mission, launched on May 12, 2023, was equipped with an optical Cherenkov Telescope (CT) designed to detect up-going air showers sourced by Earth-skimming neutrinos that interact near the Earth's limb. Presented here is an overview of the sky coverage and ToO scheduler software for EUSO-SPB2. By using the balloon trajectory coordinates and setting constraints on the positions of the Sun and Moon to ensure dark skies, we can determine if and when a source direction is slightly below the Earth's limb. From a source catalog, CT scheduling and pointing is performed to optimize the search for high-energy neutrinos coming from astrophysical sources. Some sample results for EUSO-SPB2 are shown.

Natanael Gomes-Oliveira, K. Menéndez-Delmestre, T. S. Gonçalves, D. C. Rodrigues, M. Grossi, N. Garavito-Camargo, A. Araújo, P. P. B. Beaklini, Y. Cavalcante-Coelho, A. Cortesi, L. H. Queiroga-Nuñez, T. Randriamampandry

16 pages, 6 figures, 3 tables, submitted to ApJ

Our current understanding of how dark matter (DM) is distributed within the Milky Way (MW) halo, particularly in the solar neighborhood, is based on either careful studies of the local stellar orbits or model assumptions on the global shape of the MW halo. In this work, we undertake a study of external galaxies, with the intent of providing insight to the DM distribution in MW-analog galaxies. For this, we carefully select a sample of galaxies similar to the MW, based on maximum atomic hydrogen (HI) rotational velocity (v=200-280 km s^{-1}) and morphological type (Sab-Sbc) criteria. With a need for deep, highly-resolved HI, our resulting sample is composed of 5 galaxies from the VIVA and THINGS surveys. To perform our baryonic analysis, we use deep Spitzer mid-IR images at 3.6 and 4.5 {\mu}m from the S4G survey. Based on the dynamical three-dimensional modeling software 3D-Barolo, we construct RCs and derive the gas and stellar contributions from the galaxy\'s gaseous- and stellar-disks mass surface density profiles. Through a careful decomposition of their rotation curves into their baryonic (stars, gas) and DM components, we isolate the DM contribution by using an MCMC-based approach. Based on the Sun\'s location and the MW\'s R_{25}, we define the corresponding location of the solar neighborhood in these systems. We put forward a window for the DM density (\rho=0.21-0.46 GeV cm^{-3}) at these galactocentric distances in our MW analog sample, consistent with the values found for the MW\'s local DM density, based on more traditional approaches found in the literature.

The study of a disturbed accretion disk holds great significance in the realm of astrophysics. This is because such events play a crucial role in revealing the nature of disk structure, the release of energy, and the generated shock waves. Thus, they can help explain the causes of X-ray emissions observed in black hole accretion disk systems. In this paper, we perturb the stable disk formed by spherical accretion around Kerr and EGB black holes. This perturbation reveals one- and two-armed spiral shock waves on the disk's surface. We find a strong connection between these waves and the black hole's spin parameter (a/M) and the EGB coupling constant ($\alpha$). Specifically, we found that as alpha increases in the negative direction, the dynamics of the disk and the waves become more chaotic. Additionally, we observe that the angular momentum of the perturbing matter significantly affects mass accretion and the oscillation of the arising shock waves. This allows us to observe changes in QPOs frequencies. Particularly, perturbations with angular momentum matches the observed C-type QPOs frequencies of GRS 1915 + 105 source. Thus, we conclude that the possibility of the shock waves occurring within the vicinity of GRS 1915 + 105 is substantial.

Maximiliano Isi, Will M. Farr

2 pages, 2 figures; a reproducible article prepared with ShowYourWork hosted at this https URL

Cotesta et al. (2022) reanalyze the GW150914 ringdown, arguing against the presence of an overtone and suggesting claims of its detection in Isi et al. (2019) were driven by noise. Here we point out a number of technical errors in that analysis, including a software bug, and show that features highlighted as problematic are in fact expected and encountered in simulated data. After fixes, the code in used in Cotesta et al. (2022) produces results consistent with the presence of the overtone. All code and data are available at https://github.com/maxisi/gw150914_rd_comment

Daniel J. Díaz-González, Roberto Galván-Madrid, Adam Ginsburg, Frédérique Motte, Pierre Dell'Ova, Stan Kurtz, Nichol Cunningham, Amelia M. Stutz, Fabien Louvet, Timea Csengeri, Manuel Fernández-López, Patricio Sanhueza, Thomas Nony, Rudy Rivera-Soto, Rodrigo H. Álvarez-Gutiérrez, Melanie Armante, Melisse Bonfand, Sylvain Bontemps, Antoine Gusdorf, Hong-Li Liu

Accepted to The Astrophysical Journal Supplement

We present the combination of ALMA-IMF and single-dish continuum images from the Mustang-2 Galactic Plane Survey (MGPS90) at 3 millimeters and the Bolocam Galactic Plane Survey (BGPS) at 1 millimeter. Six and ten out of the fiffteen ALMA-IMF fields are combined with MGPS90 and BGPS, respectively. The combination is made via the feathering technique. We used the dendrogram algorithm throughout the combined images, and performed further analysis in the six fields with combination in both bands (G012.80, W43-MM1, W43-MM2, W43-MM3, W51-E, W51-IRS2). In these fields, we calculated spectral index maps and used them to separate regions dominated by dust or free-free emission, and then performed further structural analysis. We report the basic physical parameters of the dust-dominated (column densities, masses) and ionized (emission measures, hydrogen ionization photon rates) structures. We also searched for multi-scale relations in the dust-dominated structures across the analyzed fields, finding that the fraction of mass in dendrogram leaves (which we label as "Leaf Mass Eficiency", LME) as a function of molecular gas column density follows a similar trend: a rapid, exponential-like growth, with maximum values approaching 100% in most cases. The observed behaviour of the LME with gas column is tentatively interpreted as an indicator of large star formation activity within the ALMA-IMF protoclusters. W51-E and G012.80 stand out as cases with comparatively large and reduced potential for further star formation, respectively.

Willaim R. Dunn, Dimitra Koutroumpa, Jennifer A. Carter, Kip D. Kuntz, Sean McEntee, Thomas Deskins, Bryn Parry, Scott Wolk, Carey Lisse, Konrad Dennerl, Caitriona M. Jackman, Dale M. Weigt, F. Scott Porter, Graziella Branduardi-Raymont, Dennis Bodewits, Fenn Leppard, Adam Foster, G. Randall Gladstone, Vatsal Parmar, Stephenie Brophy-Lee, Charly Feldman, Jan-Uwe Ness, Renata Cumbee, Maxim Markevitch, Ralph Kraft, Akos Bogdan, Anil Bhardwaj, Affelia Wibisono, Francois Mernier

White Paper for the Line Emission Mapper Astrophysics APEX X-ray Probe

The Line Emission Mapper's (LEM's) exquisite spectral resolution and effective area will open new research domains in Astrophysics, Planetary Science and Heliophysics. LEM will provide step-change capabilities for the fluorescence, solar wind charge exchange (SWCX) and auroral precipitation processes that dominate X-ray emissions in our Solar System. The observatory will enable novel X-ray measurements of historically inaccessible line species, thermal broadening, characteristic line ratios and Doppler shifts - a universally valuable new astrophysics diagnostic toolkit. These measurements will identify the underlying compositions, conditions and physical processes from km-scale ultra-cold comets to the MK solar wind in the heliopause at 120 AU. Here, we focus on the paradigm-shifts LEM will provide for understanding the nature of the interaction between a star and its planets, especially the fundamental processes that govern the transfer of mass and energy within our Solar System, and the distribution of elements throughout the heliosphere. In this White Paper we show how LEM will enable a treasure trove of new scientific contributions that directly address key questions from the National Academies' 2023-2032 Planetary Science and 2013-2022 Heliophysics Decadal Strategies. The topics we highlight include: 1. The richest global trace element maps of the Lunar Surface ever produced; insights that address Solar System and planetary formation, and provide invaluable context ahead of Artemis and the Lunar Gateway. 2. Global maps of our Heliosphere through Solar Wind Charge Exchange (SWCX) that trace the interstellar neutral distributions in interplanetary space and measure system-wide solar wind ion abundances and velocities; a key new understanding of our local astrosphere and a synergistic complement to NASA IMAP observations of heliospheric interactions...

Wilmar Cardona, Jose L. Palacios-Córdoba, César A. Valenzuela-Toledo

30 pages, 7 figures, 2 tables

Since current challenges faced by $\Lambda$CDM might be hinting at new unravelled physics, here we investigate a plausible cosmological model where a vector field acts as source of dark energy. In particular, we examine whether an energy-momentum exchange between dark energy and dark matter could provide an explanation for current discrepancies in cosmological parameters. We carefully work out equations governing both background and linear order perturbations and implement them in a Boltzmann code. We found that a negative coupling makes the dark energy equation of state less negative and closer to a cosmological constant during the matter dominated epoch than an uncoupled vector dark energy model. While the effect of the coupling is hardly noticeable on the growth of matter density perturbations, matter velocity perturbations are enhanced at late-times when dark energy dominates. Therefore, data of redshift space distortions help to narrow down these kinds of couplings in the dark sector. We computed cosmological constraints and found common parameters also present in $\Lambda$CDM are in good agreement with the Planck Collaboration baseline result. However, our best fit predicts a much higher growth rate of matter perturbations at low redshift, thus exacerbating the disagreement with redshift space distortions data. We conclude that our coupled vector dark energy model does not solve current tensions (i.e., $H_0$ and $\sigma_8$). Moreover, having three additional parameters with respect to $\Lambda$CDM, the coupled vector dark energy model is heavily disfavoured by Bayesian evidence.

Feiyu Zhao, Ruxi Liang, Zepei Yang, Huanyuan Shan, Qian Zheng, Qiqian Zhang, Quan Guo

14 pages, 10 figures, 2 tables

We calculate the reflection of diffuse galactic emission by meteor trails and investigate its potential relationship to Meteor Radio Afterglow (MRA). The formula to calculate the reflection of diffuse galactic emission is derived from a simplified case, assuming that the signals are mirrored by the cylindrical over-dense ionization trail of meteors. The overall observed reflection is simulated through a ray tracing algorithm together with the diffuse galactic emission modelled by the GSM sky model. We demonstrate that the spectrum of the reflected signal is broadband and follows a power law with a negative spectral index of around -1.3. The intensity of the reflected signal varies with local sidereal time and the brightness of the meteor and can reach 2000 Jy. These results agree with some previous observations of MRAs. Therefore, we think that the reflection of galactic emission by meteor trails can be a possible mechanism causing MRAs, which is worthy of further research.

In this Letter, we report a potential candidate of recoiling supermassive black hole (rSMBH) in SDSS J1619 based on similar velocity shifts and line widths of the blue-shifted broad components in H$\alpha$ and [O~{\sc iii}] doublet. The measured line width ratio between blue-shifted broad H$\alpha$ and broad [O~{\sc iii}] line is 1.06, if compared with common values around 5.12 for normal Type-1 AGN, indicating different properties of the blue-shifted broad components in SDSS J1619 from those of normal QSOs. The virial BH mass $M_{BHr}$ derived from the broad H$\alpha$ is consistent with the mass expected from the M_{BH}-\sigma relation. The similar velocity shifts and line widths of the blue-shifted broad components in H$\alpha$ and [O~{\sc iii}] and the virial BH mass derived from the H$\alpha$ broad line emissions that is consistent with the mass expected from the M_{BH}-\sigma~ relation, can be explained by a rSMBH scenario. Besides the rSMBH scenario, either the similar line widths of the blue-shifted broad components in H$\alpha$ and in [O~{\sc iii}] or the consistency between the virial BH mass and the mass expected from the M_{BH}-\sigma~ relation cannot be explained by the other proposed models in SDSS J1619.

D. Bockelee-Morvan, E. Lellouch, O. Poch, E. Quirico, S. Cazaux, I. de Pater, T. Fouchet, P.M. Fry, P. Rodriguez-Ovalle, F. Tosi, M.H. Wong, I. Boshuizen, K. de Kleer, L.N. Fletcher, L. Meunier, A. Mura, L. Roth, J. Saur, B. Schmitt, S.K. Trumbo, M.E. Brown, J. O'Donoghue, G.S. Orton, M.R. Showalter

35 pages, 34 figures

JWST NIRSpec IFU (2.9-5.3 mu) and MIRI MRS (4.9-28.5 mu) observations were performed on both the leading and trailing hemispheres of Ganymede with a spectral resolution of ~2700. Reflectance spectra show signatures of water ice, CO2 and H2O2. An absorption feature at 5.9 mu is revealed and is tentatively assigned to sulfuric acid hydrates. The CO2 4.26-mu band shows latitudinal and longitudinal variations in depth, shape and position over the two hemispheres, unveiling different CO2 physical states. In the ice-rich polar regions, which are the most exposed to Jupiter's plasma irradiation, the CO2 band is redshifted with respect to other terrains. In the leading northern polar cap, the CO2 band is dominated by a high wavelength component at ~4.27 mu, consistent with CO2 trapped in amorphous water ice. At equatorial latitudes (and especially on dark terrains) the observed band is broader and shifted towards the blue, suggesting CO2 adsorbed on non-icy materials. Amorphous ice is detected in the ice-rich polar regions, and is especially abundant on the leading northern polar cap. In both hemispheres the north polar cap ice appears to be more processed than the south polar cap. A longitudinal modification of the H2O ice molecular structure and/or nano/micrometre-scale texture, of diurnal or geographic origin, is observed in both hemispheres. Ice frost is observed on the morning limb of the trailing hemisphere, possibly formed during the night from the recondensation of water subliming from the warmer subsurface. Reflectance spectra of the dark terrains are compatible with the presence of Na-/Mg-sulfate salts, sulfuric acid hydrates, and possibly phyllosilicates mixed with fine-grained opaque minerals, having an highly porous texture. Mid-IR brightness temperatures indicate a rough surface and a very low thermal inertia of 20-40 J m-2 s-0.5 K-1, consistent with a porous surface.

J. Wongphechauxsorn, D. J. Champion, M. Bailes, V. Balakrishnan, E. D. Barr, M. C. i Bernadich, N. D. R. Bhat, M. Burgay, A. D. Cameron, W. Chen, C. M. L. Flynn, A. Jameson, S. Johnston, M. J. Keith, M. Kramer, C. Ng, A. Possenti, R. Sengar, R. M. Shannon, B. Stappers, W. van Straten

12 pages, 6 figures, 4 tables, Accepted for publication on Monthly Notices of the Royal Astronomical Society

The HTRU-S Low Latitude survey data within 1$^{\circ}$of the Galactic Centre (GC) were searched for pulsars using the Fast Folding Algorithm (FFA). Unlike traditional Fast Fourier Transform (FFT) pipelines, the FFA optimally folds the data for all possible periods over a given range, which is particularly advantageous for pulsars with low-duty cycle. For the first time, a search over acceleration was included in the FFA to improve its sensitivity to binary pulsars. The steps in dispersion measure (DM) and acceleration were optimised, resulting in a reduction of the number of trials by 86 per cent. This was achieved over a search period range from 0.6-s to 432-s, i.e. 10 per cent of the observation time (4320s), with a maximum DM of 4000 pc cm$^{-3}$ and an acceleration range of $\pm 128$m s$^{-2}$. The search resulted in the re-detections of four known pulsars, including a pulsar which was missed in previous FFT processing of this survey. This result indicates that the FFA pipeline is more sensitive than the FFT pipeline used in the previous processing of the survey within our parameter range. Additionally, we discovered a 1.89-s pulsar, PSR J1746-2829, with a large DM, located~0.5 from the GC. Follow-up observations revealed that this pulsar has a relatively flat spectrum($\alpha=-0.9\pm0.1$) and has a period derivative of $\sim1.3\times10^{-12}$ s s$^{-1}$, implying a surface magnetic field of $\sim5.2\times10^{13}$ G and a characteristic age of $\sim23000$ yr. While the period, spectral index, and surface magnetic field strength are similar to many radio magnetars, other characteristics such as high linear polarization are absent.

Mayank Narang, Manoj P., Himanshu Tyagi, Dan M. Watson, S. Thomas Megeath, Samuel Federman, Adam E. Rubinstein, Robert Gutermuth, Alessio Caratti o Garatti, Henrik Beuther, Tyler L. Bourke, Ewine F. Van Dishoeck, Neal J. Evans II, Guillem Anglada, Mayra Osorio, Thomas Stanke, James Muzerolle, Leslie W. Looney, Yao-Lun Yang, Pamela Klaassen, Nicole Karnath, Prabhani Atnagulov, Nashanty Brunken, William J. Fischer, Elise Furlan, Joel Green, Nolan Habel, Lee Hartmann, Hendrik Linz, Riwaj Pokhrel, Rohan Rahatgaonkar, Will R. M. Rocha, Patrick Sheehan, Katerina Slavicinska, Amelia Stutz, John J. Tobin, Lukasz Tychoniec, Scott Wolk

To be submitted to ApJL. Comments and feedback welcome

Investigating Protostellar Accretion (IPA) is a JWST Cycle 1 GO program that used NIRSpec IFU and MIRI MRS to obtain 2.9--28~$\mu$m spectral cubes of young, deeply embedded, protostars with luminosities of 0.2 to 10,000~L$_{\odot}$ and central masses of 0.15 to 12~M$_{\odot}$. In this Letter, we report the discovery of a highly collimated atomic jet from the Class 0 protostar IRAS~16253-2429, the lowest luminosity (mass) source in the IPA program. The collimated jet is clearly detected in multiple [Fe~II] lines, [Ne~II], [Ni~II], and H~I lines, but not in molecular emission. From our analysis, we find that the atomic jet has a velocity of about 169~$\pm$~15~km\,s$^{-1}$, after correcting for inclination. The width of the jet increases with distance from the central protostar from 23 to~60 au, corresponding to an opening angle of 2.6~$\pm$~0.5\arcdeg. By comparing the measured flux ratios of various fine structure lines to those predicted by simple shock models, we derive a shock velocity of 54~km\,s$^{-1}$ and a preshock density of 2.0$\times10^{3}$~cm$^{-3}$ at the base of the jet. From these quantities, and assuming a cylindrical cross-section for the jet, we derive an upper limit for the mass loss rate from the protostar of 1.1$\times10^{-10}~M_{\odot}$~yr~$^{-1}$. The low mass loss rate is consistent with simultaneous measurements of low mass accretion rate ($\sim 1.3 \times 10^{-9}~M_{\odot}$~yr~$^{-1}$) for IRAS~16253-2429 from JWST observations (Watson et al. in prep), indicating that the protostar is in a quiescent accretion phase. Our results demonstrate that very low-mass protostars can drive highly collimated, atomic jets, even during the quiescent phase.

Amit K. Mittal, Brian L Babler, Snezana Stanimirovic, Nickolas Pingel

Accepted in ApJ

Interstellar turbulence shapes the HI distribution in the Milky Way (MW). How this affects large-scale statistical properties of HI column density across the MW remains largely unconstrained. We use approx 13,000 square-degree GALFA-HI survey to map statistical fluctuations of HI over the 40 km s-1 velocity range. We calculate the spatial power spectrum (SPS) of HI column density image by running a 3-degree kernel and measuring SPS slope over a range of angular scales from 16 arcmin to 20 degree. Due to GALFA complex observing and calibration strategy, we construct detailed estimates of the noise contribution and account for GALFA beam effects on SPS. This allows us to systematically analyze HI images that trace a wide range of interstellar environments. We find that SPS slope varies between -2.6 at high Galactic latitudes, and -3.2 close to Galactic plane. The range of SPS slope values becomes tighter when we consider HI optical depth and line-of-sight length caused by the plane-parallel geometry of HI disk. This relatively uniform, large-scale distribution of SPS slope is suggestive of large-scale turbulent driving being a dominant mechanism for shaping HI structures in the MW and/or the stellar feedback turbulence being efficiently dissipated within dense molecular clouds. Only at latitudes above 60 degrees we find evidence for HI SPS slope being consistently more shallow. Those directions are largely within the Local Bubble, suggesting the recent history of this cavity, shaped by multiple supernovae explosions, has modified the turbulent state of HI and/or fractions of HI phases.

Luca Moscadelli, André Oliva, Gabriele Surcis, Alberto Sanna, Maria Teresa Beltrán, Rolf Kuiper

14 pages, 12 figures, accepted for publication in Astronomy & Astrophysics

Our goal is to measure and model the magnetic field distribution in the disk wind of the young stellar object (YSO) IRAS 21078+5211. We performed sensitive global Very Long Baseline Interferometry observations of the polarized emission of the 22 GHz water masers tracing individual streamlines of the magnetohydrodynamic (MHD) disk wind in IRAS 21078+5211. Our resistive-radiative-gravito-MHD simulations of a jet around a forming massive star are able to reproduce the maser kinematics in the inner jet cavity. We measure a weak level of 0.3%-3.2% of linear and circular polarization in 24 and 8 water masers, respectively. The detected polarized masers sample the direction and the strength of the magnetic field along five distinct streamlines within the inner 100 au region of the disk wind. Along the four streamlines at smaller radii from the jet axis (< 25 au), the sky-projected direction of the magnetic field forms, in most cases, a small offset angle of < 30$^{\circ}$ with the tangent to the streamline. Along the stream at larger radii (50-100 au), the magnetic field is sampled at only three separated positions, and it is found to be approximately perpendicular to the streamline tangent at heights of approximately 10 and 40 au, and parallel to the tangent at about 70 au. According to our simulations, the magnetic field lines should coincide with the flow streamlines in the inner jet cavity. The small tilt in the magnetic field direction observed along the inner streams can be well explained by Faraday rotation, assuming a realistic low level of ionization for the molecular shell of the jet of namely 10$^{-2}$. The magnetic field amplitudes measured from maser circular polarization are all within a relatively small range of 100-700 mG, which is in good agreement with the simulation results and consistent with reduced magnetic diffusivity in the jet cavity owing to efficient shock ionization.

Alphonse C. Sterling, Ronald L. Moore, Navdeep K. Panesar

Solar quiet- and coronal-hole region coronal jets frequently clearly originate from erupting minifilaments, but active-region jets often lack an obvious erupting-minifilament source. We observe a coronal-jet-productive active region (AR), AR 12824, over 2021 May 22 0 -- 8 UT, primarily using Solar Dynamics Observatory (SDO) Atmospheric Imaging Array (AIA) EUV images and SDO/Helioseismic and Magnetic Imager (HMI) magnetograms. Jets were concentrated in two locations in the AR: on the south side and on the northwest side of the AR's lone large sunspot. The south-location jets are oriented so that we have a clear view of the jets' origin low in the atmosphere: their source is clearly minifilaments erupting from locations showing magnetic flux changes/cancelations. After erupting a projected distance ~<5" away from their origin site, the minifilaments erupt outward onto far-reaching field as part of the jet's spire, quickly losing their minifilament character. In contrast, the northwest-location jets show no clear erupting minifilament, but the source site of those jets are obscured along our line-of-sight by absorbing chromospheric material. EUV and magnetic data indicate that the likely source sites were ~>15" from where the we first see the jet spire; thus an erupting minifilament would likely lose its minifilament character before we first see the spire. We conclude that such AR jets could work like non-AR jets, but the erupting-minifilament jet source is often hidden by obscuring material. Another factor is that magnetic eruptions making some AR jets carry only a harder-to-detect comparatively thin (~1--2") minifilament "strand."

Michael D. McManus, Kristopher G. Klein, Davin Larson, Stuart D. Bale, Trevor A. Bowen, Jia Huang, Roberto Livi, Ali Rahmati, Orlando Romeo, Jaye Verniero, Phyllis Whittlesey

Ion scale wave events or "wave storms" in the solar wind are characterised by enhancements in magnetic field fluctuations as well as coherent magnetic field polarisation signatures at or around the local ion cyclotron frequencies. In this paper we study in detail one such wave event from Parker Solar Probe's (PSP) fourth encounter, consisting of an initial period of left-handed (LH) polarisation abruptly transitioning to a strong period of right-handed (RH) polarisation, accompanied by clear core-beam structure in both the alpha and proton velocity distribution functions. A linear stability analysis shows that the LH polarised waves are anti-Sunward propagating Alfv\'en/ion cyclotron (A/IC) waves primarily driven by a proton cyclotron instability in the proton core population, and the RH polarised waves are anti-Sunward propagating fast magnetosonic/whistler (FM/W) waves driven by a firehose-like instability in the secondary alpha beam population. The abrupt transition from LH to RH is caused by a drop in the proton core temperature anisotropy. We find very good agreement between the frequencies and polarisations of the unstable wave modes as predicted by linear theory and those observed in the magnetic field spectra. Given the ubiquity of ion scale wave signatures observed by PSP, this work gives insight into which exact instabilities may be active and mediating energy transfer in wave-particle interactions in the inner heliosphere, as well as highlighting the role a secondary alpha population may play as a rarely considered source of free energy available for producing wave activity.

In this work we combined AWSoM's non-equilibrium ionization [NEI] calculations from (Szente:2022) with the synthetic spectral computations of SPECTRUM (Szente:2019), to predict non-equilibrium line intensities across the entire domain of the AWSoM 3D global model. We find that the resulting spectra are strongly affected by non-equilibrium effects in the fast wind regions and streamer edges and that these effects propagate to narrowband images from SoHO/EIT, SECCHI/EUVI and SDO/AIA. The dependence shows a different nature for each line observed resulting in significant changes in line intensity, which need to be accounted for during plasma diagnostics. However, we also find that these effects depend on the local plasma properties, and that no single correction can be developed to account for non-equilibrium effects in observed spectra and images. Comparing to observational data we saw that the changes due to NEI, while significant, are not sufficient to account for the differences between Hinode/EIS spectra and AWSoM/SPECTRUM predictions.

Fast radio bursts (FRBs) are millisecond radio signals from cosmological distances. As they propagate, FRBs can interact with ambient photons and initiate a quantum cascade that can limit the electric field strength. This paper examines whether some observed bright and brief FRBs may challenge this limit if the source is not relativistic. The size of a static FRB source is estimated as $R\sim ct$, where $t$ is the time scale of the FRB and $c$ denotes the speed of light. But for a relativistic source moving at the Lorentz factor $\Gamma$, the size is $R \sim 2 \Gamma^2 c t $. Using an FRB catalog, we plot the luminosity-duration distribution. Most FRBs fall below the limit for a static source, but two events have higher luminosity and shorter duration. This suggests these bursts may originate from relativistic sources, although more data is needed to confirm this.

Hawi Yohanis Wakjira, D. A. Mosunova, E. S. Postnikova, N. V. Chupina, S. V. Vereshchagin

We study of possible encounters in past epochs of the open star cluster NGC 1977 with host stars. For this purpose, the age of the cluster was determined based on our catalog data. Stars with planetary systems were selected from the NASA Archive. The age of the cluster was determined using the color - absolute magnitude diagram and the isochron system. By extending the track of the movement of the cluster and stars in past epochs, 10 Myr. The time of the maximum approach 32 pc of the host star with planetary system TOI-2796 with the NGC 1977 are found. The place of approach in the sky is shown, this point can be considered as the place of appearance of interstellar comets. Thus, the result of our work is that the we found approach of the host star to the cluster entailed effects associated with the gravitational influence of the cluster on the nuclei of comets located in the outer parts of the Oort cloud of the planetary system. The effect of approach on comets is estimated.

Sasha Boone, David Grant, Mark Hammond

11 pages, 9 figures. Submitted to MNRAS

We present an analytic theory for the resolution attainable via eclipse mapping of exoplanets, based on the Fourier components of the brightness distribution on the planetary disk. We find that the impact parameter determines which features can and cannot be seen, via the angle of the stellar edge relative to the axis of the orbit during the eclipse. We estimate the signal-to-noise ratio as a function of mapping resolution, and use this to determine the attainable resolution for a given star-planet system. We test this theory against numerical simulations and find good agreement; in particular, our predictions for the resolution as a function of stellar edge angle are accurate to the simulated data to within 10% over a wide range of angles. Our prediction for the number of spatial modes that can be constrained given a light curve error is similarly accurate. Finally, we give a list of exoplanets with the best expected resolution for observations with the NIRISS SOSS, NIRSpec G395H, and MIRI LRS instruments on JWST.

L. González-Sánchez, A. Veselinova, A. Martín Santa María, E. Yurtsever, R. Biswas, K.Giri, N. Sathyamurthy, U. Lourderaj, R. Wester, F. A. Gianturco

We report new results from quantum calculations of energy-transfer processes taking place in interstellar environments and involving two newly observed molecular species: C$_5$N$^-$ and C$_7$N$^-$ in collision with He atoms and the p-H$_2$ molecules. These species are part of the anionic molecular chains labeled as cyanopolyynes which have been observed over the years in molecule-rich Circumstellar Envelopes and in molecular clouds. In the present work, we first carry out new $ab$ $initio$ calculations for the C$_7$N$^-$ interaction potential with He atom and then obtain state-to-state rotationally inelastic cross sections and rate coefficients involving the same transitions which have been observed experimentally by emission in the interstellar medium (ISM) from both of these linear species. For the C$_5$N$^-$/He system we extend the calculations already published in our earlier work (see reference below) to compare more directly the two molecular anions. We extend further the quantum calculations by also computing in this work collision rate coefficients for the hydrogen molecule interacting with C5N$^-$, using our previously computed interaction potential. Additionally, we obtain the same rate coefficients for the C$_7$N$^-$/H$_2$ system by using a scaling procedure that makes use of the new C$_7$N$^-$/He rate coefficients, as discussed in detail in the present paper. Their significance in affecting internal state populations in ISM environments where the title anions have been found is analyzed by using the concept of critical density indicators. Finally, similarities and differences between such species and the comparative efficiency of their collision rate coefficients are discussed. These new calculations suggest that, at least for the case of these longer chains, the rotational populations could reach local thermal equilibrium conditions within their observational environments.

Jin-Ping Zhu

Submitted to MNRAS Letter on September 29th. Comments are welcome. 8 pages, 1 table, 3 figures, and 1 beautiful schematic figure in the appendix

A population of binary stellar-mass black hole (BBH) mergers are believed to occur embedded in the accretion disk of active galactic nuclei (AGNs). In this {\em Letter}, we demonstrate that the jets from these BBH mergers can propagate collimatedly within the disk atmosphere along with a forward shock and a reverse shock forming at the jet head. Efficient proton acceleration by these shocks is usually expected before the breakout, leading to the production of TeV$-$PeV neutrinos through interactions between these protons and electron-radiating photons via photon-meson production. AGN BBH mergers occurring in the outer regions of the disk are more likely to produce more powerful neutrino bursts. Taking the host AGN properties of the potential GW190521 electromagnetic (EM) counterpart as an example, one expects $\gtrsim1$ neutrino events detectable by IceCube if the jet is on-axis and the radial location of the merger is $R\gtrsim10^5R_{\rm{g}}$, where $R_{\rm{g}}$ is the gravitational radius of the supermassive BH. Neutrino bursts from AGN BBH mergers could be detected by IceCube following the observation of gravitational waves (GWs), serving as precursor signals before the detection of EM breakout signals. AGN BBH mergers are potential target sources for future joint GW, neutrino, and EM multi-messenger observations.

Jin-Ping Zhu, Ying Qin, Zhen-Han-Tao Wang, Rui-Chong Hu, Bing Zhang, Shichao Wu

Submitted to MNRAS on September 29th, 10 pages, 5 figures, comments are welcome

Super-Eddington accretion of neutron stars (NSs) has been suggested both observationally and theoretically. In this paper, we propose that NSs in close-orbit binary systems with companions of helium (He) stars, most of which systems form after the common-envelope phase, could experience super-Eddington stable Case BB/BC mass transfer (MT), and can sometimes occur accretion-induced collapses (AICs) to form lower mass-gap black holes (mgBHs). Our detailed binary evolution simulations reveal that AIC events tend to happen if the primaries NS have an initial mass $\gtrsim1.7\,M_\odot$ with an accretion rate of $\gtrsim300$ times the Eddington limit. These mgBHs would have a mass nearly equal to or slightly higher than the NS maximum mass. The remnant mgBH--NS binaries after the core collapses of He stars are potential progenitors of gravitational-wave (GW) source. Multimessenger observation between GW and kilonova signals from a population of high-mass binary NS and mgBH--NS mergers formed through super-Eddington stable MT are helpful in constraining the maximum mass and equation of state of NSs. S230529ay, a mgBH--NS merger candidate recently detected in the fourth observing run of the LIGO-Virgo-KAGRA Collaboration, could possibly originate from this formation scenario.

Joshua T. Povick, David L. Nidever, Pol Massana, Steven R. Majewski, Yuxi (Lucy)Lu, Maria-Rosa L. Cioni, Doug Geisler, Szabolcs Mészáros, Christian Nitschelm, Andrés Almeida, Richard R. Lane, Penélope Longa-Peña

27 pages, 22 figures, and 11 tables

We determine radial- and age-abundance gradients of the Small Magellanic Cloud (SMC) using spectra of 2,062 red giant branch (RGB) field stars observed by SDSS-IV / APOGEE-2S. With coverage out to $\sim$9 kpc in the SMC, these data taken with the high resolution ($R \sim 22,500$) APOGEE $H$-band spectrograph afford the opportunity to measure extensive radial gradients for as many as 24 abundance ratios. The SMC is found to have an overall metallicity gradient of $-$0.0546 $\pm$ 0.0043 dex/kpc. Ages are calculated for every star to explore the evolution of the different abundance gradients. As a function of age, many of the gradients show a feature 3.66--5.58 Gyr ago, which is especially prominent in the [X/H] gradients. Initially many gradients flatten until about $\sim$5.58 Gyr ago, but then steepen in more recent times. We previously detected similar evolutionary patterns in the Large Magellanic Cloud (LMC) which are attributed to a recent interaction between the LMC and SMC. It is inferred that the feature in the SMC gradients was caused by the same interaction. The age-[X/Fe] trends, which track average [X/Fe] over time, are flat, demonstrating a slow enrichment history for the SMC. When comparing the SMC gradients to the LMC and MW, normalized to disk scale length ($R_\text{d}$), the [X/Fe] and [X/Mg] gradients are similar, but there is a dichotomy between the dwarfs and the Milky Way (MW) for the [X/H] gradients. The median MW [X/H] gradient around $-$0.125 dex/$R_\text{d}$ whilst the Clouds have gradients of about $-$0.075 dex/$R_\text{d}$.

T. Hussenot-Desenonges, T. Wouters, N. Guessoum, I. Abdi, A. Abulwfa, C. Adami, J. F. Agüí Fernández, T. Ahumada, V. Aivazyan, D. Akl, S. Anand, C. M. Andrade, S. Antier, S. A. Ata, P. D'Avanzo, Y. A. Azzam, A. Baransky, S. Basa, M. Blazek, P. Bendjoya, S. Beradze, P. Boumis, M. Bremer, R. Brivio, V. Buat, M. Bulla, O. Burkhonov, E. Burns, S. B. Cenko, W. Corradi, M. W. Coughlin, F. Daigne, T. Dietrich, D. Dornic, J.-G. Ducoin, P.-A. Duverne, E. G. Elhosseiny, F. I. Elnagahy, M. A. El-Sadek, M. Ferro, E. Le Floc'h, M. Freeberg, J. P. U. Fynbo, D. Götz, E. Gurbanov, G. M. Hamed, E. Hasanov, B. F. Healy, K. E. Heintz, P. Hello, R. Inasaridze, A. Iskandar, N. Ismailov, L. Izzo, S. Jhawar, T. Jegou du Laz, T. M. Kamel, S. Karpov, A. Klotz, E. Koulouridis, N. P. Kuin, et al. (51 additional authors not shown)

GRB~230812B is a bright and relatively nearby ($z =0.36$) long gamma-ray burst that has generated significant interest in the community and therefore has been subsequently observed over the entire electromagnetic spectrum. We report over 80 observations in X-ray, ultraviolet, optical, infrared, and sub-millimeter bands from the GRANDMA (Global Rapid Advanced Network for Multi-messenger Addicts) network of observatories and from observational partners. Adding complementary data from the literature, we then derive essential physical parameters associated with the ejecta and external properties (i.e. the geometry and environment) and compare with other analyses of this event (e.g. Srinivasaragavan et al. 2023). We spectroscopically confirm the presence of an associated supernova, SN2023pel, and we derive a photospheric expansion velocity of v $\sim$ 17$\times10^3$ km $s^{-1}$. We analyze the photometric data first using empirical fits of the flux and then with full Bayesian Inference. We again strongly establish the presence of a supernova in the data, with an absolute peak r-band magnitude $M_r = - 19.41 \pm 0.10$. We find a flux-stretching factor or relative brightness $k_{\rm SN}=1.04 \pm 0.09$ and a time-stretching factor $s_{\rm SN}=0.68 \pm 0.05$, both compared to SN1998bw. Therefore, GRB 230812B appears to have a clear long GRB-supernova association, as expected in the standard collapsar model. However, as sometimes found in the afterglow modelling of such long GRBs, our best fit model favours a very low density environment ($\log_{10}({n_{\rm ISM}/{\rm cm}^{-3}}) = -2.16^{+1.21}_{-1.30}$). We also find small values for the jet's core angle $\theta_{\rm core}={1.70^{+1.00}_{-0.71}} \ \rm{deg}$ and viewing angle. GRB 230812B/SN2023pel is one of the best characterized afterglows with a distinctive supernova bump.

Mordehai Milgrom

26 pages, 2 Figures. Bases on a talk presented at the "MOND at 40'' conference at St' Andrews University, July 2023

Practically all the full-fledged MOND theories propounded to date are of the modified-gravity (MG) type: they modify only the Newtonian Poisson action of the gravitational potential, or the general-relativistic Einstein-Hilbert action, leaving other terms (inertia) intact. Here, I discuss the interpretation of MOND as modified inertia (MI). My main aim is threefold: (a) to advocate exploring MOND theories beyond MG, and appreciating their idiosyncracies, (b) to highlight the fact that secondary predictions of such theories can differ materially from those of MG theories, (c) to demonstrate some of this with specific MI models. I discuss some definitions and generalities concerning MI. I then present instances of MI in physics, and the lessons we can learn from them for MOND. I then concentrate on a specific class of nonrelativistic, MOND, MI models, and contrast their predictions with those of the two workhorse, MG theories, AQUAL and QUMOND. The MI models predict possibly a stronger external-field effect -- e.g. on low acceleration systems in the solar neighborhood -- such as very wide binary stars -- and on vertical motions in disc galaxies. More generally, the workings of the effect are rather different, and depend in different ways on dimensionless characteristics of the system, such as frequency ratios of the external and internal fields, eccentricity of trajectories, etc. These models predict a {\it much} weaker effect of the Galactic field in the inner Solar System than is predicted by AQUAL/QUMOND. I also show how noncircular motions -- such as those perpendicular to the disc -- modify the standard, algebraic mass-discrepancy-acceleration relation (aka RAR) that is predicted by MI for exactly circular orbits. These differences, and more that are discussed, can potentially offer ways to distinguish between theories.

L. Posch, N. Miret-Roig, J. Alves, S. Ratzenböck, J. Großschedl, S. Meingast, C. Zucker, A. Burkert

Accepted for publication as a Letter in Astronomy and Astrophysics

We study the kinematics of the recently discovered Corona Australis (CrA) chain of clusters by examining the 3D space motion of its young stars using Gaia DR3 and APOGEE-2 data. While we observe linear expansion between the clusters in the Cartesian XY directions, the expansion along Z exhibits a curved pattern. To our knowledge, this is the first time such a nonlinear velocity-position relation has been observed for stellar clusters. We propose a scenario to explain our findings, in which the observed gradient is caused by stellar feedback, accelerating the gas away from the Galactic plane. A traceback analysis confirms that the CrA star formation complex was located near the central clusters of the Scorpius Centaurus (Sco-Cen) OB association 10-15 Myr ago. It contains massive stars and thus offers a natural source of feedback. Based on the velocity of the youngest unbound CrA cluster, we estimate that a median number of about two supernovae would have been sufficient to inject the present-day kinetic energy of the CrA molecular cloud. This number agrees with that of recent studies. The head-tail morphology of the CrA molecular cloud further supports the proposed feedback scenario, in which a feedback force pushed the primordial cloud from the Galactic north, leading to the current separation of 100 pc from the center of Sco-Cen. The formation of spatially and temporally well-defined star formation patterns, such as the CrA chain of clusters, is likely a common process in massive star-forming regions.

Gokul P. Srinivasaragavan, Vishwajeet Swain, Brendan M. O'Connor, Shreya Anand, Tomás Ahumada, Daniel A. Perley, Robert Stein, Jesper Sollerman, Christoffer Fremling, S. Bradley Cenko, Sarah Antier, Nidhal Guessoum, Thomas Hussenot-Desenonges, Patrice Hello, Stephen Lesage, Erica Hammerstein, M. Coleman Miller, Igor Andreoni, Varun Bhalerao, Joshua S. Bloom, Anirban Dutta, Avishay Gal-Yam, K-Ryan Hinds, Amruta D. Jaodand, Mansi M. Kasliwal, Harsh Kumar, Alexander Kutyrev, Fabio Ragosta, Vikram Ravi, Kritti Sharma, Rishabh S. Teja, Sheng Yang, G. C. Anupama, Eric C. Bellm, Michael W. Coughlin, Frank J. Masci, Utkarsh Pathak, Josiah Purdum, Oliver J. Roberts, Roger Smith, Avery Wold

20 pages, 7 Figures, 1 Table, Submitted to ApJ Letters

We report observations of the optical counterpart of the long gamma-ray burst (LGRB) GRB 230812B, and its associated supernova (SN) SN 2023pel. The proximity ($z = 0.36$) and high energy ($E_{\gamma, \rm{iso}} \sim 10^{53}$ erg) make it an important event to study as a probe of the connection between massive star core-collapse and relativistic jet formation. With a phenomenological power-law model for the optical afterglow, we find a late-time flattening consistent with the presence of an associated SN. SN 2023pel has an absolute peak $r$-band magnitude of $M_r = -19.46 \pm 0.18$ mag (about as bright as SN 1998bw) and evolves on quicker timescales. Using a radioactive heating model, we derive a nickel mass powering the SN of $M_{\rm{Ni}} = 0.38 \pm 0.01$ $\rm{M_\odot}$, and a peak bolometric luminosity of $L_{\rm{bol}} \sim 1.3 \times 10^{43}$ $\rm{erg}$ $\rm{s^{-1}}$. We confirm SN 2023pel's classification as a broad-lined Type Ic SN with a spectrum taken 15.5 days after its peak in $r$ band, and derive a photospheric expansion velocity of $v_{\rm{ph}} = 11,300 \pm 1,600$ $\rm{km}$ $\rm{s^{-1}}$ at that phase. Extrapolating this velocity to the time of maximum light, we derive the ejecta mass $M_{\rm{ej}} = 1.0 \pm 0.6$ $\rm{M_\odot}$ and kinetic energy $E_{\rm{KE}} = 1.3^{+3.3}_{-1.2} \times10^{51}$ $\rm{erg}$. We find that GRB 230812B/SN 2023pel has SN properties that are mostly consistent with the overall GRB-SN population. The lack of correlations found in the GRB-SN population between SN brightness and $E_{\gamma, \rm{iso}}$ for their associated GRBs, across a broad range of 7 orders of magnitude, provides further evidence that the central engine powering the relativistic ejecta is not coupled to the SN powering mechanism in GRB-SN systems.

M. C. Bersten, M. Orellana, G. Folatelli, L. Martinez, M. P. Piccirilli, T. Regna, L. M. Román Aguilar, K. Ertini

Submitted to A&A Letter

Context: Supernova (SN) 2023ixf is among the most nearby Type II SNe in the last decades. As such, there is a wealth of observational data of both the event itself and of the associated object identified in pre-explosion images. This allows to perform a variety of studies that aim at determining the SN properties and the nature of the putative progenitor star. Modelling of the light curve is a powerful method to derive physical properties independently of direct progenitor analyses. Aims: To investigate the physical nature of SN 2023ixf based on hydrodynamical modelling of its bolometric light curve and expansion velocities during the complete photospheric phase. Methods: A grid of one dimensional explosions was calculated for evolved stars of different masses. We derived properties of SN 2023ixf and its progenitor by comparing our models with the observations. Results: The observations are well reproduced by the explosion of a star with zero age main sequence mass of f $M_\mathrm{ZAMS} = 12 M_\odot$ , an explosion energy of $1.2 \times 10^{51}$ erg, and a nickel production of 0.05M . This indicates that SN 2023ixf was a normal event. Our modelling suggests a limit of $M_\mathrm{ZAMS} < 15 M_\odot$ and therefore favours the low mass range among the results from pre-explosion observations.

C. Burger-Scheidlin, R. Brose, J. Mackey, M. D. Filipović, P. Goswami, E. Mestre Guillen, E. de Oña Wilhelmi, I. Sushch

11 pages, 6 figures

The supernova remnant (SNR) G288.8-6.3 was recently discovered as a faint radio shell at large Galactic latitude using observations with ASKAP in the EMU survey. Here, we make the first detailed investigation of the $\gamma$-ray emission from the G288.8-6.3 region, aiming to characterise the high-energy emission in the GeV regime from the newly discovered SNR, dubbed Ancora. 15 years of Fermi-Large Area Telescope (LAT) data were analysed at energies between 400 MeV and 1 TeV and the excess seen in the region was modelled using different spatial and spectral models. We detect spatially extended $\gamma$-ray emission coinciding with the radio SNR, with detection significance up to 8.8 $\sigma$. A radial disk spatial model in combination with a power-law spectral model with an energy flux of $(4.80 \pm 0.91) \times 10^{-6}$ $\text{MeV}$ $\text{cm}^{-2}$ $\text{s}^{-1}$, with the spectrum extending up to around 5 GeV was found to be the preferred model. Morphologically, hotspots seen above 1 GeV are well-correlated with the bright western part of the radio shell. The emission is more likely to be of leptonic origin given the estimated gas density in the region and the estimated distance and age of the SNR, but a hadronic scenario cannot be ruled out. Ancora is the eighth SNR detected at high Galactic latitude with Fermi-LAT. This new population of remnants has the potential to constrain the physics of particle diffusion and escape from SNRs into the Galaxy.

Enrico Pinna, Fabio Rossi, Guido Agapito, Alfio Puglisi, Cédric Plantet, Essna Ghose, Matthieu Bec, Marco Bonaglia, Runa Briguglio, Guido Brusa, Luca Carbonaro, Alessandro Cavallaro, Julian Christou, Olivier Durney, Steve Ertel, Simone Esposito, Paolo Grani, Juan Carlos Guerra, Philip Hinz, Michael Lefebvre, Tommaso Mazzoni, Brandon Mechtley, Douglas L. Miller, Manny Montoya, Jennifer Power, Barry Rothberg, Gregory Taylor, Amali Vaz, Marco Xompero, Xianyu Zhang

13 pages, 10 figures, Adaptive Optics for Extremely Large Telescopes 7th Edition, 25-30 Jun 2023 Avignon (France)

The SOUL systems at the Large Bincoular Telescope can be seen such as precursor for the ELT SCAO systems, combining together key technologies such as EMCCD, Pyramid WFS and adaptive telescopes. After the first light of the first upgraded system on September 2018, going through COVID and technical stops, we now have all the 4 systems working on-sky. Here, we report about some key control improvements and the system performance characterized during the commissioning. The upgrade allows us to correct more modes (500) in the bright end and increases the sky coverage providing SR(K)>20% with reference stars G$_{RP}$<17, opening to extragalcatic targets with NGS systems. Finally, we review the first astrophysical results, looking forward to the next generation instruments (SHARK-NIR, SHARK-Vis and iLocater), to be fed by the SOUL AO correction.

Scott D. Hull, Miki Nakajima, Natsuki Hosono, Robin M. Canup, Rene Gassmöller

To be published in The Planetary Science Journal, 51 pages, 34 figures, 4 tables

The amount of vapor in the impact-generated protolunar disk carries implications for the dynamics, devolatilization, and moderately volatile element (MVE) isotope fractionation during lunar formation. The equation of state (EoS) used in simulations of the giant impact is required to calculate the vapor mass fraction (VMF) of the modeled protolunar disk. Recently, a new version of M-ANEOS ("Stewart M-ANEOS") was released with an improved treatment of heat capacity and expanded experimental Hugoniot. Here, we compare this new M-ANEOS version with a previous version ("N-SPH M-ANEOS") and assess the resulting differences in smoothed particle hydrodynamics (SPH) simulations. We find that Stewart M-ANEOS results in cooler disks with smaller values of VMF and results in differences in disk mass that are dependent on the initial impact angle. We also assess the implications of the minimum "cutoff" density ($\rho_{c}$), similar to a maximum smoothing length, that is set as a fast-computing alternative to an iteratively calculated smoothing length. We find that the low particle resolution of the disk typically results in $>40\%$ of disk particles falling to $\rho_c$, influencing the dynamical evolution and VMF of the disk. Our results show that choice of EoS, $\rho_{c}$, and particle resolution can cause the VMF and disk mass to vary by tens of percent. Moreover, small values of $\rho_{c}$ produce disks that are prone to numerical instability and artificial shocks. We recommend that future giant impact SPH studies review smoothing methods and ensure the thermodynamic stability of the disk over simulated time.

Seok-Jun Chang, Nicole Arulanantham, Max Gronke, Gregory J. Herczeg, Edwin A. Bergin

17 pages, 18 figures, Submitted to MNRAS

Lyman-$\alpha$ (Ly$\alpha$) is the strongest emission line in UV spectra from T-Tauri stars. Due to its resonant nature, Ly$\alpha$ emission carries information about the physical properties of the H I medium via the scattering process. This work presents spatially resolved Ly$\alpha$ emission across a protoplanetary disk in the iconic face-on T-Tauri star TW Hya, observed with HST-STIS at spatial offsets 0$''$, $\pm 0.2''$, and $\pm 0.4''$. To comprehensively interpret these Ly$\alpha$ spectra, we utilize a 3D Monte-Carlo radiative transfer simulation in a wind-disk geometry. Successfully reproducing the observed spectra requires scattering contributions from both the wind and the H I disk. We constrain the properties of the wind, the H I column density ($\sim 10^{20} \rm cm^{-2}$) and the outflow velocity ($\sim 200 \rm km s^{-1}$). To reproduce the observed spatial distribution of Ly$\alpha$, we find that the wind must cover the H I disk when viewed face-on. Furthermore, to explore the effect of Ly$\alpha$ radiative transfer in T-Tauri stars, we compute the radiation field within the scattering medium and reveal that the wind reflection causes more Ly$\alpha$ photons to penetrate the disk. We also show the dependence between the disk inclination angle and the spatially resolved Ly$\alpha$ spectra. Understanding the role of Ly$\alpha$ emission in T-Tauri stars is pivotal for decoding the complex interactions between the winds, protoplanetary disks, and surrounding environments, which can significantly impact the chemistry in the protoplanetary disk. Our observation and modeling of spatially resolved Ly$\alpha$ show the necessity of spatially resolved Ly$\alpha$ observation of a broad range of targets.

The density functional theory (DFT) is the most versatile electronic structure method used in quantum chemical calculations, and is increasingly applied in astrochemical research. This mini-review provides an overview of the applications of DFT calculations in understanding the chemistry that occurs in star-forming regions. We survey investigations into the formation of biologically-relevant compounds such as nucleobases in the interstellar medium, and also covers the formation of both achiral and chiral amino acids, as well as biologically-relevant molecules such as sugars, and nitrogen-containing polycyclic aromatic hydrocarbons. Additionally, DFT calculations are used to estimate the potential barriers for chemical reactions in astronomical environments. We conclude by noting several areas that require more research, such as the formation pathways of chiral amino acids, complex sugars and other biologically-important molecules, and the role of environmental factors in the formation of interstellar biomolecules.

To investigate the physical nature of neutrino-heating on the result of a 1-dimensional core-collapse supernova. Colgate were the first to suggest that neutrinos may play a crucial role in core collapse supernova by taking up gravitational binding energy from the core and depositing it in the rest of the star. The fluid is contained in a shock tube in a region extending from the neutrino-sphere of a star out 1000 km, and irradiated with a neutrino flux emanating from the surface of the neutrino-sphere into the shock tube. Interaction due to electron-neutrino scattering off of fluid nucleons is used to account for neutrino heating of the fluid. The numerical method used is the Godunov method implementing an exact Riemann solver Rezzolla when needed. The simulated core-collapse produces an energy output of up to $10^{36}$J on a timescale of 3.33 s. It was found that the Godunov method performs very well using Sod data, with standard deviations of between $0.22-0.04$%. Thus, there is high confidence that the exact Riemann solver is working correctly and that the Godunov method is also reproducing the exact solutions to the Sod data with high confidence. A runtime of 3.33 s was used. The objective was to determine what would happen to the shock system over longer timescales, but the simulations showed an explosion in a much shorter time frame. It was found that the shock not only continues to move outward, but is also driven by large energy and pressure behind the shock. The density profiles show that fluid mass is pushed outward, but the fluid velocity actually reversed on timescales close to 3.33 s. In this paper, net mass movement occurs at 500-600 km and on a longer timescale of 3.33 s mass has moved out to 700 km. This supports the \emph{delayed post bounce shock mechanism}.

Athul Pradeepkumar Girija

9 pages, 6 figures

At the far reaches of the outer Solar System, the ice giants remain the last class of planets yet to be studied using orbiters. The 2023-2032 Planetary Science Decadal Survey has underscored the importance of the ice giants in understanding the origin, formation, and evolution of our Solar System. The enormous heliocentric distance of Uranus presents considerable mission design challenges, the most important being able to reach Uranus within a reasonable time. The present study presents two examples of aerocapture enabled short flight time, fast trajectories for Uranus orbiter missions, and highlights the enormous benefits provided by aerocapture. The first is an EEJU trajectory with a launch opportunity in July 2031 with a flight time of 8 years. The second is an EJU trajectory with a launch opportunity in June 2034 with a flight time of only 5 years. Using the Falcon Heavy Expendable, the available launch capability is 4950 kg and 1400 kg respectively for the two trajectories. Both trajectories have a high arrival speed of 20 km/s, which provides sufficient corridor width for aerocapture. Compared to propulsive insertion architectures which take 13 to 15 years, the fast trajectories offer significant reduction in the flight time.

Lin Tang, Weipeng Lin, Yang Wang, Jing Li, Yanyao Lan

8 figures, 2 tables, Accepted for publication in ApJ

In this paper, by analyzing mock images from the IllustrisTNG100-1 simulation, we examine the properties of the diffuse light and compare them to those of central and satellite galaxies. Our findings suggest that the majority of the diffuse light originates from satellites. This claim is supported by the similarity between the age and metallicity distributions of the diffuse light and those of the satellites. Notably, the color distribution of the diffuse light gradually evolves to resemble that of the centrals at lower redshifts, suggesting a coevolution or passive process. The radial profiles of the diffuse light reveal distinct trends, with the inner regions displaying a relatively flat distribution and the outer regions showing a descending pattern. This finding suggests that the formation of the diffuse light is influenced by both major mergers and stellar tidal stripping. Moreover, strong correlations are found between the stellar mass of the diffuse light and the overall stellar mass of the satellites, as well as between the stellar mass of the diffuse light and the number of satellites within groups or clusters. These relationships can be described by power-law and logarithmic functions. Overall, the diffuse light components predominantly originate from satellites with intermediate ages and metallicities. These satellites typically fall within the stellar mass range of $\rm 8<\log_{10}M_{star}/M_{\odot}< 10$ and the color range of $\rm -1<[g-r]^{0.1}< 0$. As the redshift decreases, the growth of the diffuse light is primarily influenced by the redder satellites, while the most massive and reddest satellites have minimal roles in its growth.

HD 175167b is a cold ($P_{b}\sim 1200$ days) Jupiter with a minimum mass of $M_{p}\sin i=7.8\pm3.5\ M_J$ orbiting a Sun-like star, first discovered by the Magellan Planet Search Program based on MIKE observations. Through a joint analysis of the MIKE data and the Gaia two-body orbital solution, Winn (2022) found a companion mass of $M_{p}=14.8\pm1.8\ M_J$ and suggested that it might be better designated as a brown dwarf. Additional publicly available radial velocity data from Magellan/PFS better constrains the model, and reveals that the companion is a massive cold Jupiter with a mass of $M_p=10.2\pm0.4\ M_{J}$ and a period of $P_b=1275.8\pm0.4$ days. The planet orbit is inclined by $i=38.6\pm1.7^{\circ}$ with an eccentricity of $0.529\pm0.002$.

J. N. H. S. Aditya, Hyein Yoon, James R. Allison, Tao An, Rajan Chhetri, Stephen J. Curran, Jeremy Darling, Kimberly L. Emig, Marcin Glowacki, Emily Kerrison, Bärbel S. Koribalski, Elizabeth K. Mahony, Vanessa A. Moss, John Morgan, Elaine M. Sadler, Roberto Soria, Renzhi Su, Simon Weng, Matthew Whiting

28 pages, 9 figures and 7 Tables. Submitted to MNRAS

We report an ASKAP search for associated HI 21-cm absorption against bright radio sources from the Molonglo Reference Catalogue (MRC) 1-Jy sample. The search uses pilot survey data from the ASKAP First Large Absorption Survey in \hi (FLASH) covering the redshift range $0.42 < z < 1.00$. From a sample of 62 MRC 1-Jy radio galaxies and quasars in this redshift range we report three new detections of associated HI 21-cm absorption, yielding an overall detection fraction of $1.8\%^{+4.0\%}_{-1.5\%}$. The detected systems comprise two radio galaxies (MRC 2216$-$281 at $z=0.657$ and MRC 0531$-$237 at $z=0.851$) and one quasar (MRC 2156$-$245 at $z=0.862$). The MRC 0531$-$237 absorption system is the strongest found to date, with a velocity integrated optical depth of $\rm 143.8 \pm 0.4 \ km \ s^{-1}$. All three objects with detected HI 21-cm absorption are peaked-spectrum or compact steep-spectrum (CSS) radio sources, classified based on our SED fits to the spectra. Two of them show strong interplanetary scintillation at 162 MHz, implying that the radio continuum source is smaller than 1 arcsec in size even at low frequencies. Among the class of peaked-spectrum and compact steep-spectrum radio sources, the HI detection fraction is $23\%^{+22\%}_{-13\%}$. This is consistent within $1\sigma$ with a detection fraction of $\approx 42\%^{+21\%}_{-15\%}$ in earlier reported GPS and CSS samples at intermediate redshifts ($0.4 < z < 1.0$). All three detections have a high 1.4 GHz radio luminosity, with MRC 0531$-$237 and MRC 2216$-$281 having the highest values in the sample, $\rm > 27.5 \ W \ Hz^{-1}$. The preponderance of extended radio sources in our sample could partially explain the overall low detection fraction, while the effects of a redshift evolution in gas properties and AGN UV luminosity on the neutral gas absorption still need to be investigated.

P. Marigo, P. Woitke, E. Tognelli, L. Girardi, B. Aringer, A. Bressan

14 pages, 8 figures, resubmitted to ApJ following moderate revision

In this study we compute the equation of state and Rosseland mean opacity from temperatures of T~30000 K down to T~400 K, pushing the capabilities of the AESOPUS code (Marigo et al., 2022; Marigo & Aringer, 2009) into the regime where solid grains can form. The GGchem code (Woitke et al. 2018) is used to solve the chemistry for temperatures less than ~3000 K. Atoms, molecules, and dust grains in thermodynamic equilibrium are all included in the equation of state. To incorporate monochromatic atomic and molecular cross sections, an optimized opacity sampling technique is used. The Mie theory is employed to calculate the opacity of 43 grain species. Tables of Rosseland mean opacities for scaled-solar compositions are provided. Based on our computing resources, opacities for other chemical patterns, as well as various grain sizes, porosity, and shapes, can be easily computed upon user request to the corresponding author.

S. Yamada, T. Suada, Y. Komiya, M. Aikawa, M. Y. Fujimoto

22 pages, 13 figures, 1 table. Accepted for publication in Publications of the Astronomical Society of Japan

Carbon-enhanced metal-poor (CEMP) stars in the Galactic halo have a wide range of neutron-capture element abundance patterns. To identify their origin, we investigated three modes of $s$-process nucleosynthesis that have been proposed to operate in extremely metal-poor (EMP) Asymptotic Giant Branch (AGB) stars: the convective 13C burning, which occurs when hydrogen is engulfed by the helium flash convection in low-mass AGB stars, the convective 22Ne burning, which occurs in the helium flash convection of intermediate-mass AGB stars, and the radiative 13C burning, which occurs in the $^{13}$C pocket that is formed during the inter-pulse periods. We show that the production of $s$-process elements per iron seed ($s$-process efficiency) does not depend on metallicity below $[{\rm Fe}/{\rm H}]=-2$, because 16O in the helium zone dominates the neutron poison. The convective 13C mode can produce a variety of $s$-process efficiencies for Sr, Ba and Pb, including the maxima observed among CEMP stars. The 22Ne mode only produce the lowest end of $s$-process efficiencies among CEMP models. We show that the combination of these two modes can explain the full range of observed enrichment of $s$-process elements in CEMP stars. In contrast, the 13C pocket mode can hardly explain the high level of enrichment observed in some CEMP stars, even if considering star-to-star variations of the mass of the 13C pocket. These results provide a basis for discussing the binary mass transfer origin of CEMP stars and their subgroups.

Sagiv Shiber, Emmanouil Chatzopoulos, Bradley Munson, Juhan Frank

28 pages, 19 figures, submitted to ApJ

We investigate the merger between a 16 solar mass star, on its way to becoming a red supergiant (RSG), and a 4 solar mass main-sequence companion. Our study employs three-dimensional hydrodynamic simulations using the state-of-the-art adaptive mesh refinement code Octo-Tiger. The initially corotating binary undergoes interaction and mass transfer, resulting in the accumulation of mass around the companion and its subsequent loss through the second Lagrangian point (L2). The companion eventually plunges into the envelope of the primary, leading to its spin-up and subsequent merger with the helium core. We examine the internal structural properties of the post-merger star, as well as the merger environment and the outflow driven by the merger. Our findings reveal the ejection of approximately 0.6 solar mass of material in an asymmetric and somewhat bipolar outflow. We import the post-merger stellar structure into the MESA stellar evolution code to model its long-term nuclear evolution. In certain cases, the post-merger star exhibits persistent rapid equatorial surface rotation as it evolves in the H-R diagram towards the observed location of Betelgeuse. These cases demonstrate surface rotation velocities of a similar magnitude to those observed in Betelgeuse, along with a chemical composition resembling that of Betelgeuse. In other cases, efficient rotationally-induced mixing leads to slower surface rotation. This pioneering study aims to model stellar mergers across critical timescales, encompassing dynamical, thermal, and nuclear evolutionary stages.

We propose a new model to generate large anisotropies in the scalar-induced gravitational wave (SIGW) background via sound speed resonance in the inflaton-curvaton mixed scenario. Cosmological curvature perturbations are not only exponentially amplified at a resonant frequency, but also preserve significant non-Gaussianity of local type described by $f_{\mathrm{nl}}$. Besides a significant enhancement of energy-density fraction spectrum, large anisotropies in SIGWs can be generated, because of super-horizon modulations of the energy density due to existence of primordial non-Gaussianity. A reduced angular power spectrum $\tilde{C}_{\ell}$ could reach an amplitude of $[\ell(\ell+1)\tilde{C}_{\ell}]^{1/2} \sim 10^{-2}$, leading to potential measurements via planned gravitational-wave detectors such as DECIGO. The large anisotropies in SIGWs would serve as a powerful probe of the early universe, shedding new light on the inflationary dynamics, primordial non-Gaussianity, and primordial black hole dark matter.

Christian Flores, Nagayoshi Ohashi, John J. Tobin, Jes K. Jørgensen, Shigehisa Takakuwa, Zhi-Yun Li, Zhe-Yu Daniel Lin, Merel L.R. van 't Hoff, Adele L. Plunkett, Yoshihide Yamato, Jinshi Sai (Insa Choi), Patrick M. Koch, Hsi-Wei Yen, Yuri Aikawa, Yusuke Aso, Itziar de Gregorio-Monsalvo, Miyu Kido, Woojin Kwon, Jeong-Eun Lee, Chang Won Lee, Leslie W. Looney, Alejandro Santamaría-Miranda, Rajeeb Sharma, Travis J. Thieme, Jonathan P. Williams, Ilseung Han, Suchitra Narayanan, Shih-Ping Lai

26 pages and 17 figures

We present ALMA observations of the Class I source Oph IRS63 in the context of the Early Planet Formation in Embedded Disks (eDisk) large program. Our ALMA observations of Oph IRS63 show a myriad of protostellar features, such as a shell-like bipolar outflow (in $^{12}$CO), an extended rotating envelope structure (in $^{13}$CO), a streamer connecting the envelope to the disk (in C$^{18}$O), and several small-scale spiral structures seen towards the edge of the dust continuum (in SO). By analyzing the velocity pattern of $^{13}$CO and C$^{18}$O, we measure a protostellar mass of $\rm M_\star = 0.5 \pm 0.2 $~$\rm M_\odot$ and confirm the presence of a disk rotating at almost Keplerian velocity that extends up to $\sim260$ au. These calculations also show that the gaseous disk is about four times larger than the dust disk, which could indicate dust evolution and radial drift. Furthermore, we model the C$^{18}$O streamer and SO spiral structures as features originating from an infalling rotating structure that continuously feeds the young protostellar disk. We compute an envelope-to-disk mass infall rate of $\sim 10^{-6}$~$\rm M_\odot \, yr^{-1}$ and compare it to the disk-to-star mass accretion rate of $\sim 10^{-8}$~$\rm M_\odot \, yr^{-1}$, from which we infer that the protostellar disk is in a mass build-up phase. At the current mass infall rate, we speculate that soon the disk will become too massive to be gravitationally stable.

Minkowski functionals are summary statistics that capture the geometric and morphological properties of fields. They are sensitive to all higher order correlations of the fields and can be used to complement more conventional statistics, such as the power spectrum of the field. We develop a Minkowski functional-based approach for a full likelihood analysis of mildly non-Gaussian sky maps with partial sky coverage. Applying this to the inference of cosmological parameters from the Planck mission's map of the Cosmic Microwave Background's lensing convergence, we find an excellent agreement with results from the power spectrum-based lensing likelihood. While the non-Gaussianity of current CMB lensing maps is dominated by reconstruction noise, a Minkowski functional-based analysis may be able to extract cosmological information from the non-Gaussianity of future lensing maps and thus go beyond what is accessible with a power spectrum-based analysis. We make the numerical code for the calculation of a map's Minkowski functionals, skewness and kurtosis parameters available for download from GitHub.

The CLEAR Space Weather Center of Excellence (CLEAR center) is a five year project that is funded by the NASA Space Weather Center of Excellence program. The CLEAR center will build a comprehensive prediction framework for solar energetic particles (SEPs) focusing on the timely and accurate prediction of low radiation periods (``all clear forecast") and the occurrence and characteristics of elevated periods. This will be accomplished by integrating empirical, first-principles based and machine learning (ML)-trained prediction models. In this paper, the motivation, overview, and tools of the CLEAR center will be discussed.

Gaia Collaboration, P. David, F. Mignard, D. Hestroffer, P. Tanga

Context. We report the exploitation of a sample of epoch astrometry for 157 000 asteroids, the same object in the Gaia Data Release 3, extended over the time coverage planned for the Gaia DR4, which is not expected before the end of 2025. This data set covers more than one full orbital period for the vast majority of these asteroids. The orbital solutions are derived from the Gaia data alone over a relatively short arc compared to the observation history of many of these asteroids. Aims. The work aims to produce orbital elements for a large set of asteroids based on 66 months of accurate astrometry provided by Gaia and to assess the accuracy of these orbital solutions with a comparison to the best available orbits derived from independent observations. A second validation is performed with accurate occultation timings. Methods. We processed the raw astrometric measurements of Gaia to obtain astrometric positions of moving objects with 1D sub-mas accuracy at the bright end. For each asteroid that we matched to the data, an orbit fitting was attempted in the form of the best fit of the initial conditions at the median epoch. Results. Orbits are provided in the form of state vectors in the International Celestial Reference Frame for 156 764 asteroids, including near-Earth objects, main-belt asteroids, and Trojans. For the asteroids with the best observations, the (formal) relative uncertainty is better than 1E10. Results are compared to orbits available from the Jet Propulsion Laboratory and MPC. Their orbits are based on much longer data arcs, but from positions of lower quality. The relative differences in semi-major axes have a mean of 5E10 and a scatter of 5E9.

E. Nagel, S. Czesla, A. Kaminski, M. Zechmeister, L. Tal-Or, J. H. M. M. Schmitt, A. Reiners, A. Quirrenbach, A. García López, J. A. Caballero, I. Ribas, P. J. Amado, V. J. S. Béjar, M. Cortés-Contreras, S. Dreizler, A. P. Hatzes, Th. Henning, S. V. Jeffers, M. Kürster, M. Lafarga, M. López-Puertas, D. Montes, J. C. Morales, S. Pedraz, A. Schweitzer

31 pages, 24 figures, 3 tables, accepted for publication by A&A

Light from celestial objects interacts with the molecules of the Earth's atmosphere, resulting in the production of telluric absorption lines in ground-based spectral data. Correcting for these lines, which strongly affect red and infrared wavelengths, is often needed in a wide variety of scientific applications. Here, we present the template division telluric modeling (TDTM) technique, a method for accurately removing telluric absorption lines in stars that exhibit numerous intrinsic features. Based on the Earth's barycentric motion throughout the year, our approach is suited for disentangling telluric and stellar spectral components. By fitting a synthetic transmission model, telluric-free spectra are derived. We demonstrate the performance of the TDTM technique in correcting telluric contamination using a high-resolution optical spectral time series of the feature-rich M3.0 dwarf star Wolf 294 that was obtained with the CARMENES spectrograph. We apply the TDTM approach to the CARMENES survey sample, which consists of 382 targets encompassing 22357 optical and 20314 near-infrared spectra, to correct for telluric absorption. The corrected spectra are coadded to construct template spectra for each of our targets. This library of telluric-free, high signal-to-noise ratio, high-resolution (R>80000) templates comprises the most comprehensive collection of spectral M-dwarf data available to date, both in terms of quantity and quality, and is available at the project website (this http URL).

Stéphane Paltani (university of Geneva), J. Coupon, W. G. Hartley, A. Alvarez-Ayllon, F. Dubath, J. J. Mohr, M. Schirmer, J.-C. Cuillandre, G. Desprez, O. Ilbert, K. Kuijken, N. Aghanim, B. Altieri, A. Amara, N. Auricchio, M. Baldi, R. Bender, C. Bodendorf, D. Bonino, E. Branchini, M. Brescia, J. Brinchmann, S. Camera, V. Capobianco, C. Carbone, V. F. Cardone, J. Carretero, F. J. Castander, M. Castellano, S. Cavuoti, R. Cledassou, G. Congedo, C. J. Conselice, L. Conversi, Y. Copin, L. Corcione, F. Courbin, M. Cropper, A. Da Silva, H. Degaudenzi, J. Dinis, M. Douspis, X. Dupac, S. Dusini, S. Farrens, S. Ferriol, P. Fosalba, M. Frailis, E. Franceschi, P. Franzetti, S. Galeotta, B. Garilli, W. Gillard, B. Gillis, C. Giocoli, A. Grazian, S. V. Haugan, H. Hoekstra, A. Hornstrup, et al. (157 additional authors not shown)

19 pages, 13 figures; Accepted for publication in A&A

The technique of photometric redshifts has become essential for the exploitation of multi-band extragalactic surveys. While the requirements on photo-zs for the study of galaxy evolution mostly pertain to the precision and to the fraction of outliers, the most stringent requirement in their use in cosmology is on the accuracy, with a level of bias at the sub-percent level for the Euclid cosmology mission. A separate, and challenging, calibration process is needed to control the bias at this level of accuracy. The bias in photo-zs has several distinct origins that may not always be easily overcome. We identify here one source of bias linked to the spatial or time variability of the passbands used to determine the photometric colours of galaxies. We first quantified the effect as observed on several well-known photometric cameras, and found in particular that, due to the properties of optical filters, the redshifts of off-axis sources are usually overestimated. We show using simple simulations that the detailed and complex changes in the shape can be mostly ignored and that it is sufficient to know the mean wavelength of the passbands of each photometric observation to correct almost exactly for this bias; the key point is that this mean wavelength is independent of the spectral energy distribution of the source}. We use this property to propose a correction that can be computationally efficiently implemented in some photo-z algorithms, in particular template-fitting. We verified that our algorithm, implemented in the new photo-z code Phosphoros, can effectively reduce the bias in photo-zs on real data using the CFHTLS T007 survey, with an average measured bias Delta z over the redshift range 0.4<z<0.7 decreasing by about 0.02, specifically from Delta z~0.04 to Delta z~0.02 around z=0.5. Our algorithm is also able to produce corrected photometry for other applications.

Yunlang Guo, Bo Wang, Xiangdong Li

6 pages, 3 figures, 1 table, submitted to MNRAS (revised version), comments welcome!

Black widows (BWs) are a type of eclipsing millisecond pulsars (MSPs) with low companion masses ($\lesssim0.05\,\rm M_\odot$) and tight orbits ($<1\,$d). PSR J1953+1844 is a BW with the shortest orbital period ($\sim53$ minutes) ever discovered, which was recently detected by Five-hundred-meter Aperture Spherical radio Telescope. Its companion mass is $\sim0.01\,\rm M_\odot$ according to its mass function, indicating that the companion may be a hydrogen-deficient star. However, the origin of PSR J1953+1844 is highly unclear. In this paper, we explored the origin of PSR J1953+1844 through the neutron star+He star channel, in which the system can experience ultracompact X-ray binary phase. We found that the He star donor channel can reproduce the characteristics of PSR J1953+1844, indicating that this work provides an alternative formation channel for this source. Meanwhile, the minimum orbital period of BWs formed by this channel is $\sim28$ minutes, corresponding to the companion mass of $0.058\,\rm M_\odot$. In addition, we note that even though PSR J1953+1844 has a short orbital period, it cannot be detected by the gravitational wave (GW) observatories like Laser Interferometer Space Antenna, TaiJi and TianQin. However, we still expect that the BWs with extremely tight orbit produced by this channel are the potential sources of future space-based GW observatories. Moreover, our simulations show that PSR J1953+1844 may eventually evolve into an isolated MSP.

Nicola Gaspari, Andrew J. Levan, Ashley A. Chrimes, Gijs Nelemans

13 pages, 7 figures, accepted for publication in MNRAS

The merger locations of binary neutron stars (BNSs) encode their galactic kinematics and provide insights into their connection to short gamma-ray bursts (SGRBs). In this work, we use the sample of Galactic BNSs with measured proper motions to investigate their kinematics and predict their merger locations. Using a synthetic image of the Milky Way and its Galactic potential we analyse the BNS mergers as seen from an extragalactic viewpoint and compare them to the location of SGRBs on and around their host galaxies. We find that the Galactocentric transverse velocities of the BNSs are similar in magnitude and direction to those of their Local Standards of Rest, which implies that the present-day systemic velocities are not isotropically oriented and the peculiar velocities might be as low as those of BNS progenitors. Both systemic and peculiar velocities fit a lognormal distribution, with the peculiar velocities being as low as $\sim 22-157$ km s$^{-1}$. We also find that the observed BNS sample is not representative of the whole Galactic population, but rather of systems born around the Sun's location with small peculiar velocities. When comparing the predicted BNS merger locations to SGRBs, we find that they cover the same range of projected offsets, host-normalized offsets, and fractional light. Therefore, the spread in SGRB locations can be reproduced by mergers of BNSs born in the Galactic disk with small peculiar velocities, although the median offset match is likely a coincidence due to the biased BNS sample.

Understanding the Resident Space Objects (RSOs) is nowadays a major societal challenge; indeed, the number of resident objects increases with an incredible steady pace, because of the fragmentation of uncontrolled orbiting objects and new launches. There is thus the need for a better understanding of the system as a whole to be able to determine and shape sustainable and ecological policies. This paper presents a new paradigm for analysing the structural properties of RSOs collisions from the complex systems perspective. Based on neighbouring relationships, we introduce the Resident Space Object Network (RSONet) by connecting RSOs that experience near-collisions events over a finite-time window. The structural collisional properties of RSOs are thus encoded into the RSONet and analysed with the tools of network science. This framework and paradigm shift allow us to use quantitative characteristics related to the RSONet to introduce indices for space sustainability criteria.

H. Netzel

Invited review at 2022 RR Lyrae and Cepheids conference on La Palma, 9 pages, 2 figures

Pulsations in RR Lyrae stars and classical Cepheids were thought to be relatively simple since they typically pulsate only in one or two radial modes. This picture changes at a closer look when modulation or additional low-amplitude signals are detected. I will review different multi-periodic groups known among classical pulsators, including stars showing the Blazhko modulation.

Stefano Ferrero, Cecilia Ceccarelli, Piero Ugliengo, Mariona Sodupe, Albert Rimola

The reactivity of interstellar carbon atoms (C) on the water-dominated ices is one of the possible ways to form interstellar complex organic molecules (iCOMs). In this work, we report a quantum chemical study of the coupling reaction of C ($^3$P) with an icy water molecule, alongside possible subsequent reactions with the most abundant closed shell frozen species (NH$_3$, CO, CO$_2$ and H$_2$), atoms (H, N and O), and molecular radicals (OH, NH$_2$ and CH$_3$). We found that C spontaneously reacts with the water molecule, resulting in the formation of $^3$C-OH$_2$, a highly reactive species due to its triplet electronic state. While reactions with the closed-shell species do not show any reactivity, reactions with N and O form CN and CO, respectively, the latter ending up into methanol upon subsequent hydrogenation. The reactions with OH, CH$_3$ and NH$_2$ form methanediol, ethanol and methanimine, respectively, upon subsequent hydrogenation. We also propose an explanation for methane formation, observed in experiments through H additions to C in the presence of ices. The astrochemical implications of this work are: i) atomic C on water ice is locked into $^3$C-OH$_2$, making difficult the reactivity of bare C atoms on the icy surfaces, contrary to what is assumed in astrochemical current models; and ii) the extraordinary reactivity of $^3$C-OH$_2$ provides new routes towards the formation of iCOMs in a non-energetic way, in particular ethanol, mother of other iCOMs once in the gas-phase.

Ryosuke Kobashi, Shiu-Hang Lee, Takaaki Tanaka, Keiichi Maeda

13 pages, 9 figures, 1 table, accepted for publication in ApJ

Among Type Ia supernova remnants (SNRs), Tycho's SNR has been considered as a typical object from the viewpoints of its spectroscopic, morphological and environmental properties. A recent reanalysis of Chandra data shows that its forward shock is experiencing a substantial deceleration since around 2007, which suggests recent shock interactions with a dense medium as a consequence of the cavity-wall environment inside a molecular cloud. Such a non-uniform environment can be linked back to the nature and activities of its progenitor. In this study, we perform hydrodynamic simulations to characterize Tycho's cavity-wall environment using the latest multi-epoch proper motion measurements of the forward shock. A range of parameters for the environment is explored in the hydrodynamic models to fit with the observation data for each azimuthal region. Our results show that a wind-like cavity with $\rho(r)\propto r^{-2}$ reconciles with the latest data better than a uniform medium with a constant density. In addition, our best-fit model favors an anisotropic wind with an azimuthally varying wind parameter. The overall result indicates a mass-loss rate which is unusually high for the conventional single-degenerate explosion scenario.

M.D. Afonina, A.V. Biryukov, S.B. Popov

12 pages, 2 figures, submitted to PASA

We model long-term magneto-rotational evolution of isolated neutron stars with long initial spin periods. This analysis is motivated by the recent discovery of young long-period neutron stars observed as periodic radio sources: PSR J0901-4046, GLEAM-X J1627-52, and GPM J1839-10. Our calculations demonstrate that for realistically rapid spin-down during the propeller stage all isolated neutron stars with velocities $\lesssim100$ km s$^{-1}$ are able to reach the stage of accretion from the interstellar medium within a few billion years. If neutron stars with long initial spin periods form a relatively large fraction of all Galactic neutron stars then the number of isolated accretors is sufficiently larger than it has been predicted by previous studies.

Pavan Vynatheya, Taeho Ryu, Ruediger Pakmor, Selma E. de Mink, Hagai B. Perets

14 pages, 9 figures, submitted to A&A

In the centers of dense star clusters, close encounters between stars and compact objects are likely to occur. We study tidal disruption events of main-sequence (MS) stars by stellar-mass black holes (termed $\mu$TDEs), which can shed light on the processes occurring in these clusters, including being an avenue in the mass growth of stellar-mass BHs. Using the moving-mesh hydrodynamics code \texttt{AREPO}, we perform a suite of hydrodynamics simulations of partial $\mu$TDEs of realistic, \texttt{MESA}-generated MS stars by varying the initial mass of the star ($0.5\,{\rm M}_{\rm \odot}$ and $1\,{\rm M}_{\rm \odot}$), the age of the star (zero-age, middle-age and terminal-age), the mass of the black hole ($10\,{\rm M}_{\rm \odot}$ and $40\,{\rm M}_{\rm \odot}$) and the impact parameter (yielding almost no mass loss to full disruption). We then examine the dependence of the masses, spins, and orbital parameters of the partially disrupted remnant on the initial encounter parameters. We find that the mass lost from a star decreases exponentially with increasing distance of approach and that a $1\,{\rm M}_{\rm \odot}$ star loses lesser mass than a $0.5\,{\rm M}_{\rm \odot}$. Moreover, a more evolved star is less susceptible to mass loss. Tidal torques at the closest approach spin up the remnant by factors of $10^2$--$10^4$ depending on the impact parameter. The remnant star can be bound (eccentric) or unbound (hyperbolic) to the black hole: hyperbolic orbits occur when the star's central density concentration is relatively low and the black hole-star mass ratio is high, which is the case for the disruption of a $0.5\,{\rm M}_{\rm \odot}$ star. Finally, we provide best-fit analytical formulae for a range of parameters that can be incorporated into cluster codes to model star-black hole interaction more accurately.

Engin Bahar, Hakan V. Şenavcı, Emre Işık, Gaitee A.J. Hussain, Oleg Kochukhov, David Montes, Yue Xiang

Accepted for publication by the Astrophysical Journal

Measuring coverage of dark spots on cool stars is important in understanding how stellar magnetic activity scales with the rotation rate and convection zone depth. In this respect, it is crucial to infer surface magnetic patterns on G and K stars, to reveal solar-like stellar dynamos in action. Molecular bands serve as invaluable indicators of cool spots on the surfaces of stars, as they play a crucial role in enabling accurate assessments of the extent of spot coverage across the stellar surface. Therefore, more reliable surface images can be obtained considering the inversion of atomic lines with molecular bands. In this context, we simultaneously carry out Doppler imaging (DI) using atomic lines as well as Titanium Oxide (TiO) band profiles of PW And (K2 V) and also investigate chromospheric activity indicators for the first time in the literature, using the high-resolution spectra. The surface spot distribution obtained from the inversion process represents both atomic line and TiO-band profiles quite accurately. The chromospheric emission is also correlated with photospheric spot coverage, except during a possible flare event during the observations. We detect frequent flare activity, using TESS photometry. We also introduce a new open-source, Python-based DI code SpotDIPy that allows performing surface reconstructions of single stars using the maximum entropy method. We test the code by comparing surface reconstruction simulations with the extensively used DoTS code. We show that the surface brightness distribution maps reconstructed via both codes using the same simulated data are consistent with each other.

Lingzhi Wang, Maokai Hu, Lifan Wang, Yi Yang, Jiawen Yang, Haley Gomez, Sijie Chen, Lei Hu, Ting-Wan Chen, Jun Mo, Xiaofeng Wang, Dietrich Baade, Peter Hoeflich, J. Craig Wheeler, Giuliano Pignata, Jamison Burke, Daichi Hiramatsu, D. Andrew Howell, Curtis McCully, Craig Pellegrino, Lluís Galbany, Eric Y. Hsiao, David J. Sand, Jujia Zhang, Syed A Uddin, J. P. Anderson, Chris Ashall, Cheng Cheng, Mariusz Gromadzki, Cosimo Inserra, Han Lin, N. Morrell, Antonia Morales-Garoffolo, T. E. M üller-Bravo, Matt Nicholl, Estefania Padilla Gonzalez, M. M. Phillips, J. Pineda-García, Hanna Sai, Mathew Smith, M. Shahbandeh, Shubham Srivastav, M. D. Stritzinger, Sheng Yang, D. R. Young, Lixin Yu, Xinghan Zhang

Resubmitted to Nature Astronomy, 6 main figures, 7 extended figures, and 2 extended tables

We report evidence of dust formation in the cold, dense shell behind the ejecta-circumstellar medium (CSM) interaction in the Type Ia (SNIa) SN2018evt three years after the explosion, characterized by a rise in the mid-infrared (MIR) flux accompanied by an accelerated decline in the optical. Such a dust-formation picture is also corroborated by the concurrent evolution of the profiles of the Ha emission lines. Our models suggest enhanced dust concentration at increasing distances from the SN as compared to what can be expected from the density profile of the mass loss from a steady stellar wind. This may indicate an enhanced dust presence at larger distances from the progenitor star. The dust distribution can be modeled in terms of a double-shell which assumes a sudden change of the density profile of the dust or a single-shell model with a flatter radial profile. The inferred mass-loss history of SN2018evt is consistent with a progenitor's mass loss in a binary system containing a C/O white dwarf and a massive asymptotic giant branch star. The grand rebrightening in the MIR after day +310 is attributed to the formation of new dust within the CDS region behind the forward shock. The mass of the newly-formed dust increases rapidly with time and follows a power law with an index of 4. By the time of the last MIR observations at day +1041, a total amount of 1.2+-0.2 x 10^{-2} Msun of dust has been produced, making SN 2018evt one of the most prolific dust factory among SNe with evidence of dust formations.

Qinyu Wu, Zhixing Ling, Chen Zhang, Shuang-Nan Zhang, Weimin Yuan

accepted by PASP

In recent years, tremendous progress has been made on scientific Complementary Metal Oxide Semiconductor (sCMOS) sensors, making them a promising device for future space X-ray missions. We have customized a large-format sCMOS sensor, G1516BI, dedicated for X-ray applications. In this work, a 200-nm-thick aluminum layer is successfully sputtered on the surface of this sensor. This Al-coated sensor, named EP4K, shows consistent performance with the uncoated version. The readout noise of the EP4K sensor is around 2.5 e- and the dark current is less than 0.01 e-/pixel/s at -30 degree. The maximum frame rate is 20 Hz in the current design. The ratio of single pixel events of the sensor is 45.0%. The energy resolution can reach 153.2 eV at 4.51 keV and 174.2 eV at 5.90 keV at -30 degree. The optical transmittance of the aluminum layer is approximately 1e-8 to 1e-10 for optical lights from 365 to 880 nm, corresponding to an effective aluminum thickness of around 140 to 160 nm. The good X-ray performance and low optical transmittance of this Al-coated sCMOS sensor make it a good choice for space X-ray missions. The Lobster Eye Imager for Astronomy (LEIA), which has been working in orbit for about one year, is equipped with four pieces of EP4K sensors. Furthermore, 48 pieces of EP4K sensors are used on the Wide-field X-ray Telescope (WXT) on the Einstein Probe (EP) satellite, which will be launched at the end of 2023.

Higher-order spatial laser modes have recently been investigated as candidates for reducing test-mass thermal noise in ground-based gravitational-wave detectors such as advanced LIGO. In particular, higher-order Hermite-Gauss (HG) modes have gained attention within the community for their more robust behaviors against random test-mass surface deformations and stronger sensing and control capacities. In this letter we offer experimental investigations on various aspects of HG mode interferometry. We have generated purified HG modes up to the 12-th order $\mathrm{HG}_{6,6}$ mode, with a power conversion efficiency of 38.8% and 27.7% for the $\mathrm{HG}_{3,3}$ and $\mathrm{HG}_{6,6}$ modes respectively. We demonstrated for the first time the misalignment and mode mismatch-induced power coupling loss measurements for HG modes up to the $\mathrm{HG}_{6,6}$. We report an excellent agreement with the extended numerical power loss factors that in the ``small power loss'' region converge to $2n+1$ or $n^2+n+1$ for a misaligned or mode mismatched $\mathrm{HG}_{n,n}$ mode. We also demonstrated the wavefront sensing (WFS) signal measurement for HG modes up to the $\mathrm{HG}_{6,6}$. The measurement result is accurately in accordance with theoretical WFS gain $\beta_{n,n-1}\sqrt{n} + \beta_{n,n+1}\sqrt{n+1}$ for an $\mathrm{HG}_{n,n}$ mode, with $\beta_{n,n-1}$ being the beat coefficient of the adjacent $\mathrm{HG}_{n,n}$ and $\mathrm{HG}_{n-1,n}$ modes on a split photodetector.

Hikmet Çakmak

14 pages, 9 figures and 7 tables, accepted for publication in Physics and Astronomy Reports

Determining the electron density is a challenging task in solar corona studies, as it requires certain assumptions to be made, such as symmetric, homogeneous and radial distribution, thermal equilibrium, etc. In such studies, the observed $K$ corona brightness is based on the coronal electron density. An important paper on the calculation of electron density was published in 1950 by van de Hulst in an article titled "The Electron Density of the Solar Corona". The author developed a method with some assumptions to calculate the electron density from the observed $K$ corona brightness. We presented here, a new simplified calculation method for the coronal electron density is presented. The integral equation solution given by van de Hulst is interpreted from a different perspective and the $K$ coronal electron density is calculated using only observational data without making any additional adjustments such as successive approximations and multiple attempts.

H. L. M. Osborne, V. Van Eylen, E. Goffo, D. Gandolfi, G. Nowak, C. M. Persson, J. Livingston, A. Weeks, E. Pallé, R. Luque, C. Hellier, I. Carleo, S. Redfield, T. Hirano, M. Garbaccio Gili, J. Alarcon, O. Barragán, N. Casasayas-Barris, M. R. Díaz, M. Esposito, J. S. Jenkins, E. Knudstrup, F. Murgas, J. Orell-Miquel, F. Rodler, L. Serrano, M. Stangret, S. H. Albrecht, A. Alqasim, W. D. Cochran, H. J. Deeg, M. Fridlund, A. Hatzes, J. Korth, K. W. F. Lam

Re-submitted to MNRAS following moderate review, 23 October 2023

We report on the precise radial velocity follow-up of TOI-544 (HD 290498), a bright K star (V=10.8), which hosts a small transiting planet recently discovered by the Transiting Exoplanet Survey Satellite (TESS). We collected 122 high-resolution HARPS and HARPS-N spectra to spectroscopically confirm the transiting planet and measure its mass. The nearly 3-year baseline of our follow-up allowed us to unveil the presence of an additional, non-transiting, longer-period companion planet. We derived a radius and mass for the inner planet, TOI-544b, of 2.018 $\pm$ 0.076 R$_{\oplus}$ and 2.89 $\pm$ 0.48 M$_{\oplus}$ respectively, which gives a bulk density of $1.93^{+0.30}_{-0.25}$ g cm$^{-3}$. TOI-544c has a minimum mass of 21.5 $\pm$ 2.0 M$_{\oplus}$ and orbital period of 50.1 $\pm$ 0.2 days. The low density of planet-b implies that it has either an Earth-like rocky core with a hydrogen atmosphere, or a composition which harbours a significant fraction of water. The composition interpretation is degenerate depending on the specific choice of planet interior models used. Additionally, TOI-544b has an orbital period of 1.55 days and equilibrium temperature of 999 $\pm$ 14 K, placing it within the predicted location of the radius valley, where few planets are expected. TOI-544b is a top target for future atmospheric observations, for example with JWST, which would enable better constraints of the planet composition.

Amaury H.M.J. Triaud, Julien de Wit, Frieder Klein, Martin Turbet, Benjamin V. Rackham, Prajwal Niraula, Ana Glidden, Oliver E. Jagoutz, Matej Pec, Janusz J. Petkowski, Sara Seager, Franck Selsis

35 pages, 5 figures

The conventional observables to identify a habitable or inhabited environment in exoplanets, such as an ocean glint or abundant atmospheric O$_2$, will be challenging to detect with present or upcoming observatories. Here we suggest a new signature. A low carbon abundance in the atmosphere of a temperate rocky planet, relative to other planets of the same system, traces the presence of substantial amount of liquid water, plate tectonic and/or biomass. We show that JWST can already perform such a search in some selected systems like TRAPPIST-1 via the CO$_2$ band at $4.3\,\rm \mu m$, which falls in a spectral sweet spot where the overall noise budget and the effect of cloud/hazes are optimal. We propose a 3-step strategy for transiting exoplanets: 1) detection of an atmosphere around temperate terrestrial planets in $\sim 10$ transits for the most favorable systems, (2) assessment of atmospheric carbon depletion in $\sim 40$ transits, (3) measurements of O$_3$ abundance to disentangle between a water- vs biomass-supported carbon depletion in $\sim100$ transits. The concept of carbon depletion as a signature for habitability is also applicable for next-generation direct imaging telescopes.

Yuxi Lu, Ruth Angus, Daniel Foreman-Mackey, Soichiro Hattori

Submitted to AJ. Missing citations welcome

Gyrochronology, the field of age-dating stars using mainly their rotation periods and masses, is ideal for inferring the ages of individual main-sequence stars. However, due to the lack of physical understanding of the complex magnetic fields in stars, gyrochronology relies heavily on empirical calibrations that require consistent and reliable stellar age measurements across a wide range of periods and masses. In this paper, we obtain a sample of consistent ages using the gyro-kinematic age-dating method, a technique to calculate the kinematics ages of stars. Using a Gaussian Process model conditioned on ages from this sample (~ 1 - 14 Gyr) and known clusters (0.67 - 3.8 Gyr), we calibrate the first empirical gyrochronology relation that is capable of inferring ages for single, main-sequence stars between 0.67 Gyr to 14 Gyr. Cross-validating and testing results suggest our model can infer cluster and asteroseismic ages with an average uncertainty of just over 1 Gyr. With this model, we obtain gyrochronology ages for ~ 100,000 stars within 1.5 kpc of the Sun with period measurements from Kepler and ZTF, and 384 unique planet host stars.

Delphine Porquet, Scott Hagen, Nicolas Grosso, Andrew Lobban, James N. Reeves, Valentina Braito, Chris Done

12 pages, 7 figures, accepted for publication in A&A

[Abridged] The X-ray broadband spectra of the bare AGN Mrk 110, obtained by simultaneous XMM-Newton and NuSTAR observations (Nov 2019 and April 2020), are characterised by the presence of a prominent and absorption-free smooth soft X-ray excess, moderately broad OVII and Fe Kalpha emission lines, and a lack of a strong Compton hump. While relativistic reflection as the sole emission is ruled out, a simplified combination of soft and hard Comptonisation from a warm and a hot coronae, plus mild relativistic disc reflection reproduces the data very well. We aim to confirm the physical origin of the soft X-ray excess of Mrk 110 and to determine its disc-corona system properties from its energetics using two new sophisticated models: reXcor and relagn, respectively. At both epochs, the inferred high-values of the warm-corona heating from the X-ray broadband spectral analysis using reXcor confirm that the soft X-ray excess originates mainly from a warm corona rather than relativistic reflection. The intrinsic best-fit SED determined at both epochs using relagn show a high X-ray contribution relative to the UV and are very well reproduced by a warm and hot coronae plus mild relativistic reflection. The outer radii of the hot and warm coronae are located at a few 10s and ~100 Rg, respectively. Moreover, combining the inferred low Eddington ratio (~ a few %) from this work, and previous multi-wavelength spectral and timing studies suggests that Mrk 110 could be classified as a moderate changing-state AGN. Our analysis confirms the existence of a warm corona as a significant contribution to the soft X-ray excess and UV emission in Mrk 110, adding to growing evidence that AGN accretion deviates from standard disc theory. This strengthens the importance of long-term multi-wavelength monitoring on both single targets and large AGN surveys to reveal the real nature of disc-corona system in AGN.

The pointing pattern is an integral part of designing one's observation strategy for a certain scientific goal. But accounting for the particular science case or instrument artifacts (like distortion, vignetting or large areas of bad pixels) can make it hard to predict how the exposure map of the final stack will be. To help address this problem, Gnuastro 0.21 includes a new executable program called astscript-pointing-simulate that is fully described in the Gnuastro manual and comes with a complete tutorial. The figures of this research note are reproducible with Maneage, on the Git commit 4176d29.

Marie Ygouf, Charles Beichman, Jorge Llop-Sayson, Geoffrey Bryden, Jarron Leisenring, Andras Gaspar, John Krist, Marcia Rieke, George Rieke, Schuyler Wolff, Thomas Roellig, Kate Su, Kevin Hainline, Klaus Hodapp, Thomas Greene, Michael Meyer, Doug Kelly, Karl Misselt, John Stansberry, Martha Boyer, Doug Johnstone, Scott Horner, Alexandra Greenbaum

24 pages, 17 figures

We report observations with the JWST/NIRCam coronagraph of the Fomalhaut system. This nearby A star hosts a complex debris disk system discovered by the IRAS satellite. Observations in F444W and F356W filters using the round 430R mask achieve a contrast ratio of ~ 4 x 10-7 at 1'' and ~ 4 x 10-8 outside of 3''. These observations reach a sensitivity limit <1 MJup across most of the disk region. Consistent with the hypothesis that Fomalhaut b is not a massive planet but is a dust cloud from a planetesimal collision, we do not detect it in either F356W or F444W (the latter band where a Jovian-sized planet should be bright). We have reliably detected 10 sources in and around Fomalhaut and its debris disk, all but one of which are coincident with Keck or HST sources seen in earlier coronagraphic imaging; we show them to be background objects, including the "Great Dust Cloud" identified in MIRI data. However, one of the objects, located at the edge of the inner dust disk seen in the MIRI images, has no obvious counterpart in imaging at earlier epochs and has a relatively red [F356W]-[F444W]>0.7 mag (Vega) color. Whether this object is a background galaxy, brown dwarf, or a Jovian mass planet in the Fomalhaut system will be determined by an approved Cycle 2 follow-up program. Finally, we set upper limits to any scattered light from the outer ring, placing a weak limit on the dust albedo at F356W and F444W.

Qiaoyang Hao, Shenwei Zhou, Huigen Liu

22 pages, 16 figures, accepted 2023 September 7, published 2023 September 29

Terrestrial planets in the habitable zone around nearby stars are of great interest and provide a good sample for further characteristics of their habitability. In this paper, we collect a nearby star catalog within 20 pc according to the Gaia Catalog of Nearby Stars, complete the physical parameters of the stars, and select stars that are not brown dwarfs or white dwarfs. After selection, a sample of 2234 main-sequence stars is used to estimate the extended HZ. Then we inject Earth-like planets into the extended HZ around each star and calculate the signals with four methods, i.e.; velocity amplitude for radial velocity, transit probability and depth for transit, stellar displacements for astrometry, and contrast and angular separation for imaging. Considering a typical noise model based on classic instruments, we predict the highest possible detection number of Earth-like planets via different methods in the best-case hypothetical scenario. According to this, we conclude that both astrometry and imaging have the potential to detect nearby Earth-like planets around G type stars, while radial velocity has the potential to detect 2% of nearby Earth-like planets around M stars under a precision of 0.2 m/s. Our work also provides the precision requirements for future missions to reveal the nearby Earth-like planet in the HZ.

Jian Qin, Pengjie Zhang, Haojie Xu, Yu Yu, Ji Yao, Ruijie Ma, Huanyuan Shan

Alternative to weak lensing measurements through cosmic shear, we present a weak lensing convergence $\hat{\kappa}$ map reconstructed through cosmic magnification effect in DECaLS galaxies of the DESI imaging surveys DR9. This is achieved by linearly weighing $12$ maps of galaxy number overdensity in different magnitude bins of $grz$ photometry bands. The weight is designed to eliminate the mean galaxy deterministic bias, minimize galaxy shot noise while maintaining the lensing convergence signal. We also perform corrections of imaging systematics in the galaxy number overdensity. The $\hat{\kappa}$ map has $8365$ deg$^2$ sky coverage. Given the low number density of DECaLS galaxies, the $\hat{\kappa}$ map is overwhelmed by shot noise and the map quality is difficult to evaluate using the lensing auto-correlation. Alternatively, we measure its cross-correlation with the cosmic shear catalogs of DECaLS galaxies of DESI imaging surveys DR8, which has $8365$ deg$^2$ overlap in sky coverage with the $\hat{\kappa}$ map. We detect a convergence-shear cross-correlation signal with $S/N\simeq 10$. The analysis also shows that the galaxy intrinsic clustering is suppressed by a factor $\mathcal{O}(10^2)$ and the residual galaxy clustering contamination in the $\hat{\kappa}$ map is consistent with zero. Various tests with different galaxy and shear samples, and the Akaike information criterion analysis all support the lensing detection. So is the imaging systematics corrections, which enhance the lensing signal detection by $\sim 30\%$. We discuss various issues for further improvement of the measurements.

M. Koussour, N. Myrzakulov, Alnadhief H. A. Alfedeel, Amare Abebe

Progress of Theoretical and Experimental Physics accepted version

Despite the significant accomplishments of general relativity, numerous unresolved issues persist in our understanding of the cosmos. One of the most perplexing challenges is the ongoing accelerated expansion of the Universe, which continues to elude a complete explanation. Consequently, scientists have proposed various alternative theories to GR in pursuit of a deeper understanding. In our analysis, we delve into the recently proposed modified $f(Q)$ gravity, where $Q$ represents the non-metricity scalar responsible for gravitational effects. Specifically, we investigate a cosmological model characterized by the functional form $f(Q) = Q+\alpha Q^n$, where $\alpha$ (with $\alpha \neq 0$) and $n$ serve as free parameters. Utilizing this functional form, we construct our Hubble rate, incorporating a specific equation of state to describe the cosmic fluid. Furthermore, we leverage a dataset consisting of 31 data points from Hubble measurements and an additional 1048 data points from the Pantheon dataset. These data serve as crucial constraints for our model parameters, and we employ the Markov Chain Monte Carlo (MCMC) method to explore the parameter space and derive meaningful results. With our parameter values constrained, our analysis yields several noteworthy findings. The deceleration parameter suggests a recent accelerated phase in the cosmic expansion. In addition, the EoS parameter paints a portrait of dark energy exhibiting phantom-like characteristics. Furthermore, we delve into the application of cosmological diagnostic tools, specifically the statefinder and the $Om(z)$ diagnostics. Both of these tools align with our previous conclusions, confirming the phantom-like behavior exhibited by our cosmological model. These results collectively contribute to our understanding of the dynamic interplay between gravity, dark energy, and the expanding cosmos.

Kurt Walsen, Paula Jofré, Sven Buder, Keaghan Yaxley, Payel Das, Robert Yates, Xia Hua, Theosamuele Signor, Camilla Eldridge, Alvaro Rojas-Arriagada, Patricia Tissera, Evelyn Johnston, Claudia Aguilera-Gómez, Manuela Zoccali, Gerry Gilmore, Robert Foley

Submitted to MNRAS journal. Associated catalog of high precision, Cannon-rederived abundances for GALAH solar twins to be made publicly available upon acceptance and available now upon request. See Manea et al. 2023 for a complementary, high precision, Cannon-rederived abundance catalog for GALAH red giant stars

Stellar chemical abundances have proved themselves a key source of information for understanding the evolution of the Milky Way, and the scale of major stellar surveys such as GALAH have massively increased the amount of chemical data available. However, progress is hampered by the level of precision in chemical abundance data as well as the visualization methods for comparing the multidimensional outputs of chemical evolution models to stellar abundance data. Machine learning methods have greatly improved the former; while the application of tree-building or phylogenetic methods borrowed from biology are beginning to show promise with the latter. Here we analyse a sample of GALAH solar twins to address these issues. We apply The Cannon algorithm (Ness et al. (2015)) to generate a catalogue of about 40,000 solar twins with 14 high precision abundances which we use to perform a phylogenetic analysis on a selection of stars that have two different ranges of eccentricities. From our analyses we are able to find a group with mostly stars on circular orbits and some old stars with eccentric orbits whose age-[Y/Mg] relation agrees remarkably well with the chemical clocks published by previous high precision abundance studies. Our results show the power of combining survey data with machine learning and phylogenetics to reconstruct the history of the Milky Way.

Gabriel Fabiano de Souza, Pieter Westera, Felipe Almeida-Fernandes, Guilherme Limberg, Bruno Dias, José A. Hernandez-Jimenez, Fábio R. Herpich, Leandro O. Kerber, Eduardo Machado-Pereira, Hélio D. Perottoni, Rafael Guerço, Liana Li, Laura Sampedro, Antonio Kanaan, Tiago Ribeiro, William Schoenell, Claudia Mendes de Oliveira

Accepted to MNRAS. 12 pages, 11 figures

The Magellanic Clouds are the most massive and closest satellite galaxies of the Milky Way, with stars covering ages from a few Myr up to 13 Gyr. This makes them important for validating integrated light methods to study stellar populations and star-formation processes, which can be applied to more distant galaxies. We characterized a set of stellar clusters in the Small Magellanic Cloud (SMC), using the $\textit{Southern Photometric Local Universe Survey}$. This is the first age (metallicity) determination for 11 (65) clusters of this sample. Through its 7 narrow bands, centered on important spectral features, and 5 broad bands, we can retrieve detailed information about stellar populations. We obtained ages and metallicities for all stellar clusters using the Bayesian spectral energy distribution fitting code $\texttt{BAGPIPES}$. With a sample of clusters in the color range $-0.20 < r-z < +0.35$, for which our determined parameters are most reliable, we modeled the age-metallicity relation of SMC. At any given age, the metallicities of SMC clusters are lower than those of both the Gaia Sausage-Enceladus disrupted dwarf galaxy and the Milky Way. In comparison with literature values, differences are $\Delta$log(age)$\approx0.31$ and $\Delta$[Fe/H]$\approx0.41$, which is comparable to low-resolution spectroscopy of individual stars. Finally, we confirm a previously known gradient, with younger clusters in the center and older ones preferentially located in the outermost regions. On the other hand, we found no evidence of a significant metallicity gradient.

Alison L. Coil, Serena Perrotta, David S. N. Rupke, Cassandra Lochhaas, Christy A. Tremonti, Aleks Diamond-Stanic, Drummond Fielding, James Geach, Ryan C. Hickox, John Moustakas, Gregory H. Rudnick, Paul Sell, Kelly E. Whalen

7 figures, accepted to Nature

A new class of extragalactic astronomical sources discovered in 2021, named Odd Radio Circles (ORCs, Norris et al. 2021), are large rings of faint, diffuse radio continuum emission spanning ~1 arcminute on the sky. Galaxies at the centers of several ORCs have photometric redshifts of z~0.3-0.6, implying physical scales of several 100 kiloparsecs in diameter for the radio emission, the origin of which is unknown. Here we report spectroscopic data on an ORC including strong [OII] emission tracing ionized gas in the central galaxy of ORC4 at z=0.4512. The physical extent of the [OII] emission is ~40 kpc in diameter, larger than expected for a typical early-type galaxy (Pandya et al, 2017) but an order of magnitude smaller than the large-scale radio continuum emission. We detect a ~200 km/s velocity gradient across the [OII] nebula, as well as a high velocity dispersion of ~180 km/s. The [OII] equivalent width (EW, ~50 Ang) is extremely high for a quiescent galaxy. The morphology, kinematics, and strength of the [OII] emission are consistent with the infall of shock ionized gas near the galaxy, following a larger-scale, outward moving shock driven by a galactic wind. Both the extended optical and radio emission, while observed on very different scales, may therefore result from the same dramatic event.

Paul A Crowther, M J Barlow, P Royer, D J Hillier, J M Bestenlehner, P W Morris, R Wesson

13 pages, 10 figures, plus Appendices, submitted to MNRAS

We present Herschel PACS spectroscopy of the [O III] 88.4um fine-structure line in the nearby WC8+O binary system gamma Vel to determine its oxygen abundance. The critical density of this line corresponds to several 10^5 R* such that it is spatially extended in PACS observations at the 336 pc distance to gamma Vel. Two approaches are used, the first involving a detailed stellar atmosphere analysis of gamma Vel using CMFGEN, extending to Ne ~ 10^0 cm^-3 in order to fully sample the line formation region of [O III] 88.4um. The second approach involves the analytical model introduced by Barlow et al. and revised by Dessart et al, additionally exploiting ISO LWS spectroscopy of [O III] 51.8um. We obtain higher luminosities for the WR and O components of gamma Vel with respect to De Marco et al, log L/L_sun = 5.31 and 5.56, respectively, primarily as a result of the revised (higher) interferometric distance. We obtain an oxygen mass fraction of X_O = 1.0+/- 0.3% for an outer wind volume filling factor of f = 0.5+/-0.25, favouring either standard or slightly reduced Kunz et al. rates for the ^12C(alpha, gamma)^16O reaction from comparison with BPASS binary population synthesis models. We also revisit sulphur and neon abundances in the outer wind of gamma Vel from ISO SWS spectroscopy of [S IV] 10.5um and [Ne III] 15.5um. The sulphur abundance of X_S = 0.04 +/- 0.01% agrees with the solar abundance, as expected for unprocessed elements, with the inferred neon abundance X_Ne = 1.5-0.5+0.3%, in good agreement with BPASS predictions.

Laboratory made granular-granular impact craters have been used as model analogues of planetary impact craters. These kind of craters have been observed and studied using profilometry techniques that allow to retrieve important morphologic features from the impacted surface. In this work, we propose to use a Time-of-Flight camera (Microsoft Kinect One) for the acquisition of depth data. We show comparisons between the typically used technique and the analysis derived from the Time-of-Flight data. We also release craterslab, a Python library developed to automate most of the tasks from the process of studying impact craters produced by granular projectiles hitting on the surface of granular targets. The library is able to acquire, identify, and measure morphological features of impacted surfaces through the reconstruction of 3D topographic maps. Our results show that using a Time-of-Flight camera and automating the data processing with a software library for the systematic study of impact craters can produce very accurate results while reducing the time spent on different stages of the process.

B. Barbosa, J. P. Palastro, D. Ramsey, K. Weichman, M. Vranic

8 pages, 5 figures

Electron-positron pair creation occurs throughout the universe in the environments of extreme astrophysical objects, such as pulsar magnetospheres and black hole accretion disks. The difficulty of emulating these environments in the laboratory has motivated the use of ultrahigh-intensity laser pulses for pair creation. Here we show that the phase offset between a laser pulse and its second harmonic can be used to control the relative transverse motion of electrons and positrons created in the nonlinear Breit-Wheeler process. Analytic theory and particle-in-cell simulations of a head-on collision between a two-color laser pulse and electron beam predict that with an appropriate phase offset, the electrons will drift in one direction and the positrons in the other. The resulting current may provide a collective signature of nonlinear Breit-Wheeler, while the spatial separation resulting from the relative motion may facilitate isolation of positrons for subsequent applications or detection.

Stefan Knirck, Gabe Hoshino, Mohamed H. Awida, Gustavo I. Cancelo, Martin Di Federico, Benjamin Knepper, Alex Lapuente, Mira Littmann, David W. Miller, Donald V. Mitchell, Derrick Rodriguez, Mark K. Ruschman, Matthew A. Sawtell, Leandro Stefanazzi, Andrew Sonnenschein, Gary W. Teafoe, Daniel Bowring, G. Carosi, Aaron Chou, Clarence L. Chang, Kristin Dona, Rakshya Khatiwada, Noah A. Kurinsky, Jesse Liu, Cristián Pena, Chiara P. Salemi, Christina W. Wang, Jialin Yu

7 pages, 4 figures

We present first results from a dark photon dark matter search in the mass range from 44 to 52 $\mu{\rm eV}$ ($10.7 - 12.5\,{\rm GHz}$) using a room-temperature dish antenna setup called GigaBREAD. Dark photon dark matter converts to ordinary photons on a cylindrical metallic emission surface with area $0.5\,{\rm m}^2$ and is focused by a novel parabolic reflector onto a horn antenna. Signals are read out with a low-noise receiver system. A first data taking run with 24 days of data does not show evidence for dark photon dark matter in this mass range, excluding dark photon - photon mixing parameters $\chi \gtrsim 10^{-12}$ in this range at 90% confidence level. This surpasses existing constraints by about two orders of magnitude and is the most stringent bound on dark photons in this range below 49 $\mu$eV.

Ilídio Lopes

13 pages, 1 table, 5 figures. Article published in Physical Review D,

Our study investigates the complex interaction between active neutrinos and the ultralight bosonic dark matter halo surrounding the Sun. This halo extends over several solar radii due to the Sun's gravitational field, and we represent it as a coherent oscillating classical field configuration of bosonic dark matter particles that vary in time. Our investigation has revealed that, based on the available solar neutrino flux data, these novel models do not surpass the performance of the conventional neutrino flavour oscillation model. Furthermore, we discuss how next-generation solar neutrino detectors have the potential to provide evidence for the existence or absence of the ultralight dark matter halo.

Niyaz Uddin Molla, Himanshu Chaudhary, Dhruv Arora, Farruh Atamurotov, Ujjal Debnath, G.Mustafa

21 pages, 14 figures

We investigate the strong gravitational lensing phenomena caused by a black hole with a dark matter halo. In this study, we examine strong gravitational lensing with two significant dark matter models: the universal rotation curve model and the cold dark matter model. To do this, we first numerically estimate the strong lensing coefficients and strong deflection angles for both the universal rotation curve and cold dark matter models. It is observed that the deflection angle, denoted as $\alpha_D$, increases with the parameter $\alpha$ while holding the value of $\gamma \cdot 2M$ constant. Additionally, it increases with the parameter $\gamma \cdot 2M$ while keeping the value of $\alpha$ constant. The strong deflection angle, $\alpha_D$, for the black hole with a dark matter halo, with parameters $\alpha=0$ and $\gamma \cdot 2M$, greatly enhances the gravitational bending effect and surpasses the corresponding case of the standard Schwarzschild black hole ($A=0, B=0, \alpha=0, \gamma \cdot 2M=0$). Furthermore, we investigate the astrophysical consequences through strong gravitational lensing observations, using examples of various supermassive black holes such as $M87^{*}$ and $SgrA^{*}$ located at the centers of several galaxies. It is observed that black holes with dark matter halos can be quantitatively distinguished and characterized from the standard Schwarzschild black hole ($A=0, B=0, \alpha=0, \gamma \cdot 2M=0$). The findings in our analysis suggest that observational tests for black holes influenced by dark matter halos are indeed feasible and viable.

Lorenzo Iorio

LaTex2e, 13 pages, 4 figures, 1 table. arXiv admin note: text overlap with arXiv:2310.02834

Right ascension $\alpha$ and declination $\delta$ are two of the most widely used astrometric observables in astronomical surveys targeted at bodies orbiting a primary like, e.g., the S-stars moving around the supermassive black hole in Sgr A$^\ast$ at the Galactic Center. Their post-Keplerian net shifts per orbit induced by some Newtonian (quadrupole mass moment $J_2$ of the central body) and post-Newtonian (gravitoelectromagnetic Schwarzschild and Lense-Thirring) perturbing accelerations are analytically calculated. The resulting expressions have a general validity since they hold for arbitrary orientations of the primary's spin axis $\mathbf{\hat{k}}$ in space and general orbital configurations. Numerical integrations of the equations of motion of a fictitious two-body system performed over one orbital period confirm the analytical calculations. The computational scheme adopted can be straightforwardly extended to modified models of gravity as well.

Karol Fulat, Artem Bohdan, Gabriel Torralba Paz, Martin Pohl

Accepted for publication in ApJ, 17 pages, 10 figures

Strong non-relativistic shocks are known to accelerate particles up to relativistic energies. However, for Diffusive Shock Acceleration electrons must have a highly suprathermal energy, implying a need for very efficient pre-acceleration. Most published studies consider shocks propagating through homogeneous plasma, which is an unrealistic assumption for astrophysical environments. Using 2D3V particle-in-cell simulations, we investigate electron acceleration and heating processes at non-relativistic high-Mach-number shocks in electron-ion plasma with a turbulent upstream medium. For this purpose slabs of plasma with compressive turbulence are separately simulated and then inserted into shock simulations, which requires matching of the plasma slabs at the interface. Using a novel procedure of matching electromagnetic fields and currents, we perform simulations of perpendicular shocks setting different intensities of density fluctuations ($\lesssim 10\%$) in the upstream. The new simulation technique provides a framework for studying shocks propagating in turbulent media. We explore the impact of the fluctuations on electron heating, the dynamics of upstream electrons, and the driving of plasma instabilities. Our results indicate that while the presence of the turbulence enhances variations in the upstream magnetic field, their levels remain too low to influence significantly the behavior of electrons at perpendicular shocks.

We point out, the scalar sector of gravitational perturbations may be excited by an isolated astrophysical system immersed in a universe whose accelerated expansion is not due to the cosmological constant, but due to extra field degrees of freedom. This is true even if the source of gravitational radiation did not couple directly to these additional fields. We illustrate this by considering a universe driven by a single canonical scalar field. By working within the gauge-invariant formalism, we solve for the electric components of the linearised Weyl tensor to demonstrate that both the gravitational massless spin-2 (transverse-traceless) tensor and the (Bardeen) scalar modes are generated by a generic astrophysical source. For concreteness, the Dark Energy scalar field is either released from rest, or allowed to asymptote to the minimum in a certain class of potentials; and we compute the traceless tidal forces induced by gravitational radiation from a hypothetical compact binary system residing in such a universe. Though their magnitudes are very small compared to the tensors', spin zero gravitational waves in such a canonical scalar driven universe are directly sensitive to both the Dark Energy equation of state and the eccentricity of the binary's orbit.

A triangular solution [Phys. Rev. D 107, 044005 (2023)] has recently been found to the planar circular three-body problem in the parametrized post-Newtonian (PPN) formalism, for which they focus on a class of fully conservative theories characterized by the Eddington-Robertson parameters $\beta$ and $\gamma$. The present paper extends the PPN triangular solution to quasi-elliptic motion, for which the shape of the triangular configuration changes with time at the PPN order. The periastron shift due to the PPN effects is also obtained.

Twenty years of gravity observations from various satellite missions have provided unique data about mass redistribution processes in the Earth system. This paper studies the benefit of enhanced electrostatic and novel optical accelerometers and gradiometers for the future gravimetry missions. One of the limiting factors in the current space gravimetry missions is the drift of the Electrostatic Accelerometers (EA). This study focuses on the modeling of enhanced EAs with laser-interferometric readout, so called 'optical accelerometers', and on evaluating their performance for gravity field recovery in future satellite missions. In this paper, we simulate gravimetry missions in multiple scopes, applying the various software modules for satellite dynamics integration, accelerometer (ACC) and gradiometer simulation and gravity field recovery. The total noise budget of the modeled enhanced Electrostatic and optical ACCs show a similar sensitivity as the ACC concepts from other research groups. Parametrization w.r.t. ACCs test mass (TM) weight and the gap between the test mass and surrounding electrode housing confirmed previously known results that an ACC with a heavier TM and larger gap will have better performance. Our results suggest that the anticipated gain of novel ACCs might at some point be potentially limited by noise from the inter-satellite laser ranging interferometry. In order to present the advantage of the novel sensors, time-variable background models and associated aliasing errors were not considered in our simulations. Utilization of enhanced EA and optical ACC show a significant improvement of accuracy w.r.t. current GRACE-like EA. Also, their benefit in double satellite pairs in a so called 'Bender' constellations as well as in the combination of low-low satellite-to-satellite tracking with cross-track gradiometry has been simulated.

It is well-known that the number of particles produced in cosmology, commonly defined in the literature from the Fock space of the instantaneous hamiltonian of the canonically normalized fields, is ambiguous. On the other hand, the energy computed from the energy-momentum tensor should be physical. We compare the corresponding Fock spaces and relate them through a Bogolyubov transformation. We find that for particles of spin $0$, $1$ and $3/2$ the two Fock spaces are different, whereas they are the same for spin $1/2$ fermions. For spin $0$ and $1$, for particles of high momenta the two Fock spaces align, as intuitively expected. For the spin $3/2$, one finds two puzzles. The first one is that the two corresponding Fock spaces do not match even in the limit of high momenta. The second is that whereas we provide evidence for the equivalence theorem between longitudinal gravitinos and the goldstino in terms of an exact matching between the lagrangians and the instantaneous hamiltonians for the canonically normalized fields, the energy operator computed from the Rarita--Schwinger action does not seem to be captured in a simple way by the goldstino action. Our results suggest a re-analysis of non-thermal gravitino production in cosmology.

Ricardo A. C. Cipriano, Tiberiu Harko, Francisco S. N. Lobo, Miguel A. S. Pinto, João Luís Rosa

17 pages; 6 figures

In this work, we analyze the possibility of gravitationally induced matter creation in the so-called Energy-Momentum-Squared gravity (EMSG), i.e. $f(R,T_{\mu\nu}T^{\mu\nu})$ gravity, in its dynamically equivalent scalar-tensor representation. Given the explicit nonminimal coupling between matter and geometry in this theory, the energy-momentum tensor is not generally covariantly conserved, which motivates the study of cosmological scenarios by resorting to the formalism of irreversible thermodynamics of open systems. We start by deriving the universe matter creation rates and subsequent thermodynamical properties, such as, the creation pressure, temperature evolution, and entropy evolution, in the framework of $f(R,T_{\mu\nu}T^{\mu\nu})$ gravity. These quantities are then analyzed for a Friedmann-Lema\^itre-Robertson-Walker (FLRW) background with a scale factor described by the de Sitter solution, under different assumptions for the mater distribution, namely a vacuum universe, a constant density universe, and a time-varying density universe. Finally, we explore cosmological solutions with varying Hubble parameters and provide a comparison with the standard cosmological model. Our results indicate that the cosmological evolution in the framework of EMSG are in close agreement with the observational cosmological data for low redshift.

Franco Cerino, Andrés Diaz-Pace, Emmanuel Tassone, Manuel Tiglio, Atuel Villegas

This paper is an invited contribution to the Special Issue "Recent Advances in Gravity: A Themed Issue in Honor of Prof. Jorge Pullin on his 60th Anniversary''

In a previous work we introduced, in the context of gravitational wave science, an initial study on an automated domain-decomposition approach for reduced basis through hp-greedy refinement. The approach constructs local reduced bases of lower dimensionality than global ones, with the same or higher accuracy. These ``light'' local bases should imply both faster evaluations when predicting new waveforms and faster data analysis, in particular faster statistical inference (the forward and inverse problems, respectively). In this approach, however, we have previously found important dependence on several hyperparameters, which do not appear in global reduced basis. This naturally leads to the problem of hyperparameter optimization (HPO), which is the subject of this paper. We tackle the problem through a Bayesian optimization, and show its superiority when compared to grid or random searches. We find that for gravitational waves from the collision of two spinning but non-precessing black holes, for the same accuracy, local hp-greedy reduced bases with HPO have a lower dimensionality of up to $4 \times$ for the cases here studied, depending on the desired accuracy. This factor should directly translate in a parameter estimation speedup, for instance. Such acceleration might help in the near real-time requirements for electromagnetic counterparts of gravitational waves from compact binary coalescences. In addition, we find that the Bayesian approach used in this paper for HPO is two orders of magnitude faster than, for example, a grid search, with about a $100 \times$ acceleration. The code developed for this project is available as open source from public repositories.

Indrajit Sen, Stephon Alexander, Justin Dressel

Comments welcomed

Unitarity is a difficult concept to implement in canonical quantum gravity because of state non-normalizability and the problem of time. In this work, we take a realist approach based on pilot-wave theory to address this issue in the Ashtekar formulation of the Wheeler-de Witt equation. We use the postulate of a definite configuration in the theory to define a global time for the gravitational-fermionic system recently discussed in (Phys. Rev. D 106.10 (2022): 106012), by parameterizing a variation of a Weyl-spinor that depends on the Kodama state. The total Hamiltonian constraint yields a time-dependent Schrodinger equation, without semi-classical approximations, which we use to derive a local continuity equation over the configuration space. We implement the reality conditions at the level of the guidance equation, and obtain a real spin-connection, extrinsic curvature and triad along the system trajectory. The non-normalizable Kodama state is naturally factored out of the full quantum state in the conserved current density, opening the possibility for quantum-mechanical unitarity. We also give a pilot-wave generalisation of the notion of unitarity applicable to non-normalizable states, and show the existence of equilibrium density for our system. Lastly, we find unitary states in mini-superspace by finding an approximate solution to the Hamiltonian constraint.