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Papers for Thursday, May 25 2023

Papers with local authors

K. Kohno, S. Fujimoto, A. Tsujita, V. Kokorev, G. Brammer, G. E. Magdis, F. Valentino, N. Laporte, Fengwu Sun, E. Egami, F. E. Bauer, A. Guerrero, N. Nagar, K. I. Caputi, G. B. Caminha, J.-B. Jolly, K. K. Knudsen, R. Uematsu, Y. Ueda, M. Oguri, A. Zitrin, M. Ouchi, Y. Ono, J. Gonzalez-Lopez, J. Richard, I. Smail, D. Coe, M. Postman, L. Bradley, A. M. Koekemoer, A. M. Munoz Arancibia, M. Dessauges-Zavadsky, D. Espada, H. Umehata, B. Hatsukade, F. Egusa, K. Shimasaku, K. Matsui-Morokuma, W.-H. Wang, T. Wang, Y. Ao, A. J. Baker, Minju M. Lee, C. del P. Lagos, D. H. Hughes, ALCS collaboration

6 pages, 4 figures, Proceedings of the 7th Chile-Cologne-Bonn-Symposium: Physics and Chemistry of Star Formation, V. Ossenkopf-Okada, R. Schaaf, I. Breloy (eds.)

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Paper 40 — arXiv:2305.15126
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Paper 40 — arXiv:2305.15126

The ALMA lensing cluster survey (ALCS) is a 96-hr large program dedicated to uncovering and characterizing intrinsically faint continuum sources and line emitters with the assistance of gravitational lensing. All 33 cluster fields were selected from HST/Spitzer treasury programs including CLASH, Hubble Frontier Fields, and RELICS, which also have Herschel and Chandra coverages. The total sky area surveyed reaches $\sim$133 arcmin$^2$ down to a depth of $\sim$60 $\mu$Jy beam$^{-1}$ (1$\sigma$) at 1.2 mm, yielding 141 secure blind detections of continuum sources and additional 39 sources aided by priors. We present scientific motivation, survey design, the status of spectroscopy follow-up observations, and number counts down to $\sim$7 $\mu$Jy. Synergies with JWST are also discussed.

Papers reserved for later discussion

These are papers reserved by people for discussion at a later date. All reservations are kept for 2 days after the date of the reservation.

Yuhao Zhou, Xiaohong Li, Jie Hong, Rony Keppens

14 pages, 6 figures. Accepted by A&A

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05/23/2023: arXiv:2305.13237
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05/23/2023: arXiv:2305.13237

Observations have shown that some filaments appear and disappear in the H$\alpha$ line wing images periodically. There have been no attempts to model these "winking filaments" thus far. The evaporation--condensation mechanism is widely used to explain the formation of solar filaments. Here, we demonstrate, for the first time, how multi-dimensional evaporation--condensation in an arcade setup invariably causes a stretching of the magnetic topology. We aim to check whether this magnetic stretching during cyclic evaporation--condensation could reproduce a winking filament. We used our open-source code MPI-AMRVAC to carry out 2D magnetohydrodynamic simulations based on a quadrupolar configuration. A periodic localized heating, which modulates the evaporation--condensation process, was imposed before, during, and after the formation of the filament. Synthetic H$\alpha$ and 304 \r{A}, images were produced to compare the results with observations. For the first time, we noticed the winking filament phenomenon in a simulation of the formation of on-disk solar filaments, which was in good agreement with observations. Typically, the period of the winking is different from the period of the impulsive heating. A forced oscillator model explains this difference and fits the results well. A parameter survey is also done to look into details of the magnetic stretching phenomenon. We found that the stronger the heating or the higher the layer where the heating occurs, the more significant the winking effect appears.

All other papers

Rico K. L. Lo

Submitted to the Journal of Open Source Software

Masked autoregressive flow (MAF) is a state-of-the-art non-parametric density estimation technique. It is based on the idea (known as a normalizing flow) that a simple base probability distribution can be mapped into a complicated target distribution that one wishes to approximate, using a sequence of bijective transformations. The denmarf package provides a scikit-learn-like interface in Python for researchers to effortlessly use MAF for density estimation in their applications to evaluate probability densities of the underlying distribution of a set of data and generate new samples from the data, on either a CPU or a GPU, as simple as "from denmarf import DensityEstimate; de = DensityEstimate().fit(X)". The package also implements logistic transformations to facilitate the fitting of bounded distributions.

A primordial black hole (PBH) with mass $10^{-15}\leq M_{\rm PBH}/M_{\odot}\leq 10^{-10}$ is currently beyond the sensitivity of both microlensing and black hole (BH) evaporation methods. A novel scenario has been proposed: When a PBH with mass $10^{-14}\leq M_{\rm PBH}/M_{\odot}\leq 10^{-11}$ transits through a white dwarf (WD) made up of carbon and oxygen, Bondi-Hoyle-Lyttleton (BHL) accretion in a reactive medium creates a shock wave, which generates direct detonation ignition in the WD core and then leads to thermonuclear supernovae (SNe Ia). The aim of this study is to impose constraints on the PBH to dark matter (DM) abundance fraction, $f_{\rm PBH}$, via comparing the SN Ia event rates between PBH hypotheses and observational data. For PBH fraction less than unity, we found the observed event rate prefers PBH mass region, $7.6\times 10^{-13}\leq M_{\rm PBH}/M_{\odot}\leq 6.1\times 10^{-12}$, under the Navarro-Frenk-White (NFW) profile. Meanwhile, the aforementioned PBH mass and abundance can be efficiently produced via a cosmological first-order phase transition (FOPT) in dark sector which associates with $\mathcal{O}({\rm MeV})$ energy scale and thus gives rise to complementary signals of stochastic gravitational waves (GWs) from $10^{-6}$ Hz to $10^{-5}$ Hz peak frequency which can be probed by future $\mu$Ares GW interferometer.

E. Vanzella, F. Loiacono, P. Bergamini, U. Mestric, M. Castellano, P. Rosati, M. Meneghetti, C. Grillo, F. Calura, M. Mignoli, M. Bradac, A. Adamo, G. Rihtarsic, M. Dickinson, M. Gronke, A. Zanella, F. Annibali, C. Willott, M. Messa, E. Sani, A. Acebron, A. Bolamperti, A. Comastri, R. Gilli, K. I. Caputi, M. Ricotti, C. Gruppioni, S. Ravindranath, A. Mercurio, V. Strait, N. Martis, R. Pascale, G. B. Caminha, M. Annunziatella

15 pages, 10 figures, 1 table. Submitted to A&A. Comments welcome

We present JWST/NIRSpec integral field spectroscopy (IFS) of a lensed Population III candidate stellar complex (dubbed Lensed And Pristine 1, LAP1), with a lensing-corrected stellar mass ~<10^4 Msun, absolute luminosity M_UV > -11.2 (m_UV > 35.6), confirmed at redshift 6.639 +/- 0.004. The system is strongly amplified (\mu >~ 100) by straddling a critical line of the Hubble Frontier Field galaxy cluster MACS J0416. Despite the stellar continuum is currently not detected in the Hubble and JWST/NIRCam and NIRISS imaging, arclet-like shapes of Lyman and Balmer lines, Lya, Hg, Hb and Ha are detected with NIRSpec IFS with signal-to-noise ratios SNR=5-13 and large equivalent widths (>300-2000A), along with a remarkably weak [OIII]4959-5007 at SNR ~ 4. LAP1 shows a large ionizing photon production efficiency, log(\xi_{ion}[erg~Hz^{-1}])>26. From the metallicity indexes R23 = ([OIII]4959-5007 + [OII]3727) / Hb ~< 0.74 and R3 = ([OIII]5007 / Hb) = 0.55 +/- 0.14, we derive an oxygen abundance 12+log(O/H) ~< 6.3. Intriguingly, the Ha emission is also measured in mirrored sub-components where no [OIII] is detected, providing even more stringent upper limits on the metallicity if in-situ star formation is ongoing in this region (12+log(O/H) < 6, or Z < 0.002 Zsun). The formal stellar mass limit of the sub-components would correspond to ~10^{3} Msun or M_UV fainter than -10. Alternatively, such a metal-free pure line emitting region could be the first case of a fluorescing HI gas region, induced by transverse escaping ionizing radiation from a nearby star-complex. The presence of large equivalent-width hydrogen lines and the deficiency of metal lines in such a small region, make LAP1 the most metal poor star-forming region currently known in the reionization era and a promising site that may host isolated, pristine stars.

Annalisa Citro, Danielle A. Berg, Dawn K. Erb, Matthew W. Auger, George D. Becker, Bethan L. James, Evan D. Skillman

26 pages, 16 figures

We provide one of the most comprehensive metallicity studies at z ~ 4 by analyzing the UV/optical HST photometry, and rest-frame VLT-FORS2 ultraviolet and VLT-XSHOOTER optical spectra of J0332-3557, a gravitationally lensed galaxy magnified by a factor of 20. With a 5{\sigma} detection of the auroral O III] {\lambda}1666 line, we are able to derive a direct gas metallicity estimate for our target. We find Zgas = 12 + log(O/H) = 8.26 +/- 0.06, which is compatible with an increasing of both the gas fraction and the outflow metal loading factor from z ~ 0 to z ~ 4. J0332 is the most metal-rich individual galaxy at z > 3.6 for which the C/O ratio has been measured. We derive a low log(C/O)= -1.02 +/- 0.2, which suggests that J0332 is in the early stages of ISM carbon enrichment driven mostly by massive stars. The low C/O also indicates that J0332 is characterized by a low star formation efficiency, higher yields of oxygen and longer burst duration. We find that the EW[C III]1906,9 is as low as ~ 3 {\AA}. The main drivers of the low EW[C III]1906,9 are the higher gas metallicity and the low C/O. J0332 is characterized by one diffuse and two more compact regions ~ 1 kpc in size. We find that the carbon emission mostly originates in the compact knots.

Alexandros Ziampras, Richard P. Nelson, Roman R. Rafikov

18 pages, 28 figures, 4 tables; submitted to MNRAS

ALMA observations of protoplanetary disks in dust continuum emission reveal a variety of annular structures. Attributing the existence of such features to embedded planets is a popular scenario, supported by studies using hydrodynamical models. Recent work has shown that radiative cooling greatly influences the capability of planet-driven spiral density waves to transport angular momentum, ultimately deciding the number, position, and depth of rings and gaps that a planet can carve in a disk. However, radiation transport has only been treated via local thermal relaxation, not taking into account radiative diffusion along the disk plane. We compare the previous state-of-the-art models of planet-disk interaction with local cooling prescriptions to our new models that include cooling in the vertical direction and radiative diffusion in the plane of the disk, and show that the response of the disk to the induced spiral waves can differ significantly when comparing these two treatments of the disk thermodynamics. We follow up with synthetic emission maps of ALMA systems, and show that our new models reproduce the observations found in the literature better than models with local cooling. We conclude that appropriate treatment of radiation transport is key to constraining the parameter space when interpreting ALMA observations using the planet-disk interaction scenario.

Guillermo Barro, Pablo G. Perez-Gonzalez, Dale D. Kocevski, Elizabeth J. McGrath, Jonathan R. Trump, Raymond C. Simons, Rachel S. Somerville, L. Y. Aaron Yung, Pablo Arrabal Haro, Michaela B. Bagley, Nikko J. Cleri, Luca Costantin, Kelcey Davis, Mark Dickinson, Steve L. Finkelstein, Mauro Giavalisco, Carlos Gomez-Guijarro, Nimish P. Hathi, Michaela Hirschmann, Hollis B. Akins, Benne W. Holwerda, Marc Huertas-Company, Ray A. Lucas, Casey Papovich, Lise-Marie Seille, Sandro Tacchella, Stephen M. Wilkins, Alexander de la Vega, Guang Yang, Jorge A. Zavala

26 pages, 10 figures, submitted to ApJ

We study a new population of extremely red objects (EROs) recently discovered by JWST based on their NIRCam colors F277W$-$F444W $>1.5$ mag. We find 37 EROs in the CEERS field with F444W $<28$ mag and photometric redshifts between $5<z<7$, with median $z=6.9^{+1.0}_{-1.6}$. Surprisingly, despite their red long-wavelength colors, these EROs have blue short-wavelength colors (F150W$-$F200W$\sim$0 mag) indicative of bimodal SEDs with a red, steep slope in the rest-frame optical, and a blue, flat slope in the rest-frame UV. Moreover, all these EROs are unresolved, point-like sources in all NIRCam bands. We analyze the spectral energy distributions of 8 of them with MIRI and NIRSpec observations using stellar population models and AGN templates. We find that a dusty galaxy or an obscured AGN provide similarly good SED fits but different stellar properties: massive and dusty, log M/M_sun$\sim$10 and A$_{\rm V}\gtrsim3$ mag, or low mass and obscuration, log M/M_sun$\sim$7.5 and A$_{\rm V}\sim0$ mag, hosting an obscured QSO. SED modeling does not favor either scenario, but their unresolved sizes are more suggestive of an AGN. If any EROs are confirmed to have log M/M_sun$\gtrsim10.5$, it would increase pre-JWST number densities at $z>7$ by up to a factor $\sim$60. Similarly, if they are OSOs with luminosities in the L$_{\rm bol}>10^{46-47}$ erg s$^{-1}$ range, their number would exceed that of bright blue QSOs by more than two orders of magnitude. Additional photometry at mid-IR wavelengths will reveal the true nature of the red continuum emission in these EROs and will place this puzzling population in the right context of galaxy evolution.

Constant Auclair, Erwan Allys, François Boulanger, Matthieu Béthermin, Athanasia Gkogkou, Guilaine Lagache, Antoine Marchal, Marc-Antoine Miville-Deschênes, Bruno Régaldo-Saint Blancard, Pablo Richard

Submitted to A&A. Comments welcome

The low brightness dust emission at high Galactic latitude is of interest to study the interplay between physical processes in shaping the structure of the interstellar medium (ISM), as well as to statistically characterize dust emission as a foreground to the Cosmic Microwave Background (CMB). Progress in this avenue of research have been hampered by the difficulty of separating the dust emission from the Cosmic Infrared Background (CIB). We demonstrate that dust and CIB may be effectively separated based on their different structure on the sky and use the separation to characterize the structure of diffuse dust emission on angular scales where CIB is a significant component in terms of power. We use scattering transform statistics, the Wavelet Phase Harmonics (WPH), to perform a statistical component separation using Herschel SPIRE observations. This component separation is done only from observational data using non-Gaussian properties as a lever arm, and is done at a single 250 microns frequency. This method, that we validate on mock data, gives us access to non-Gaussian statistics of the interstellar dust and an output dust map essentially free from CIB contamination. Our statistical modelling characterizes the non-Gaussian structure of the diffuse ISM down to the smallest scales observed by Herschel. We recover the power-law shape of the dust power spectrum up to a wavenumber of 2 arcmin$^{-1}$ where the dust signal represents 2 percent of the total power. The output dust map reveals coherent structures at the smallest scales which were hidden by the CIB anisotropies. It opens new observational perspectives on the formation of structure in the diffuse ISM which we discuss with reference to past work. We have succeeded to perform a statistical separation from observational data only at a single frequency by using non-Gaussian statistics.

Alex I. Malz, Mi Dai, Kara A. Ponder, Emille E.O. Ishida, Santiago Gonzalez-Gaitain, Rupesh Durgesh, Alberto Krone-Martins, Rafael S. de Souza, Noble Kennamer, Sreevarsha Sreejith, Lluis Galbany, The LSST Dark Energy Science Collaboration (DESC), The Cosmostatistics Initiative (COIN)

9 pages, 6 figures; submitted to A&A

Context: When selecting a classifier to use for a supernova Ia (SN Ia) cosmological analysis, it is common to make decisions based on metrics of classification performance, i.e. contamination within the photometrically classified SN Ia sample, rather than a measure of cosmological constraining power. If the former is an appropriate proxy for the latter, this practice would save those designing an analysis pipeline from the computational expense of a full cosmology forecast. Aims: This study tests the assumption that classification metrics are an appropriate proxy for cosmology metrics. Methods: We emulate photometric SN Ia cosmology samples with controlled contamination rates of individual contaminant classes and evaluate each of them under a set of classification metrics. We then derive cosmological parameter constraints from all samples under two common analysis approaches and quantify the impact of contamination by each contaminant class on the resulting cosmological parameter estimates. Results: We observe that cosmology metrics are sensitive to both the contamination rate and the class of the contaminating population, whereas the classification metrics are insensitive to the latter. Conclusions: We therefore discourage exclusive reliance on classification-based metrics for cosmological analysis design decisions, e.g. classifier choice, and instead recommend optimizing using a metric of cosmological parameter constraining power.

Brent Tan, Drummond B. Fielding

32 pages, 34 figures; Submitted to MNRAS

Galaxies comprise intricate networks of interdependent processes which together govern their evolution. Central among these are the multiplicity of feedback channels, which remain incompletely understood. One outstanding problem is the understanding and modeling of the multiphase nature of galactic winds, which play a crucial role in galaxy formation and evolution. We present the results of three dimensional magnetohydrodynamical tall box interstellar medium patch simulations with clustered supernova driven outflows. Fragmentation of the interstellar medium during superbubble breakout seeds the resulting hot outflow with a population of cool clouds. We focus on analyzing and modeling the origin and properties of these clouds. Their presence induces large scale turbulence, which in turn leads to complex cloud morphologies. Cloud sizes are well described by a power law distribution and mass growth rates can be modelled using turbulent radiative mixing layer theory. Turbulence provides significant pressure support in the clouds, while magnetic fields only play a minor role. We conclude that many of the physical insights and analytic scalings derived from idealized small scale simulations translate well to larger scale, more realistic turbulent magnetized winds, thus paving a path towards their necessary yet challenging inclusion in global-scale galaxy models.

Tsun Hin Navin Tsung, S. Peng Oh, Chad Bustard

33 pages, 25 figures, submitted to MNRAS

We investigate how cosmic rays (CRs) affect thermal and hydrostatic stability of circumgalactic (CGM) gas, in simulations with both CR streaming and diffusion. Local thermal instability can be suppressed by CR-driven entropy mode propagation, in accordance with previous analytic work. However, there is only a narrow parameter regime where this operates, before CRs overheat the background gas. As mass dropout from thermal instability causes the background density and hence plasma $\beta \equiv P_g/P_B$ to fall, the CGM becomes globally unstable. At the cool disk to hot halo interface, a sharp drop in density boosts Alfven speeds and CR gradients, driving a transition from diffusive to streaming transport. CR forces and heating strengthen, while countervailing gravitational forces and radiative cooling weaken, resulting in a loss of both hydrostatic and thermal equilibrium. In lower $\beta$ halos, CR heating drives a hot, single-phase diffuse wind with velocities $v \propto (t_\mathrm{heat}/t_\mathrm{ff})^{-1}$, which exceeds the escape velocity when $t_\mathrm{heat}/t_\mathrm{ff} \lesssim 0.4$. In higher $\beta$ halos, CR forces drive multi-phase winds with cool, dense fountain flows and significant turbulence. These flows are CR dominated due to "trapping" of CRs by weak transverse B-fields, and have the highest mass loading factors. Thus, local thermal instability can result in winds or fountain flows where either the heat or momentum input of CRs dominates.

Amir Sharon, Doron Kushnir, Wenlong Yuan, Lucas Macri, Adam Riess

20 pages, 12 figures. Submitted to MNRAS

The SH0ES collaboration Hubble constant determination is in a $\mathord{\sim}5\sigma$ difference with the \textit{Planck} value, known as the Hubble tension. The accuracy of the Hubble constant measured with extragalactic Cepheids depends on robust stellar-crowding background estimation. Riess et al. 2020 (R20) compared the light curves amplitudes of extragalactic and MW Cepheids to constrain an unaccounted systematic blending bias, $\gamma=-0.029\pm0.037\,\rm{mag}$, which cannot explain the required, $\gamma=0.24\pm0.05\,\rm{mag}$, to resolve the Hubble tension. Further checks by Riess et al. 2022 demonstrate that a possible blending is not likely related to the size of the crowding correction. We repeat the R20 analysis, with the following main differences: 1. We limit the extragalactic and MW Cepheids comparison to periods $P\lesssim50\,\rm{d}$, since the number of MW Cepheids with longer periods is minimal; 2. We use publicly available data to recalibrate amplitude ratios of MW Cepheids in standard passbands; 3. We remeasure the amplitudes of Cepheids in NGC 5584 and NGC 4258 in two HST filters (F555W and F350LP) to improve the empirical constraint on their amplitude ratio $A^{555}/A^{350}$. We show that the filter transformations introduce an $\mathord{\approx}0.04\,\rm{mag}$ uncertainty in determining $\gamma$, not included by R20. While our final estimate, $\gamma=0.013\pm0.057\,\rm{mag}$, is consistent with the value derived by R20, the error is somewhat larger, and the best-fit value is shifted by $\mathord{\approx}0.04\,\rm{mag}$. Although the obtained $\gamma$ for this crowding test is consistent with zero, folding (in quadratures) it is $\mathord{\approx}3.0\sigma$ away from aligning with \textit{Planck}. Future observations, especially with JWST, would allow better calibration of $\gamma$.

Mattia C. Sormani, Ashley T. Barnes, Jiayi Sun, Sophia K. Stuber, Eva Schinnerer, Eric Emsellem, Adam K. Leroy, Simon C.O. Glover, Jonathan D. Henshaw, Sharon E. Meidt, Justus Neumann, Miguel Querejeta, Thomas G. Williams, Frank Bigiel, Cosima Eibensteiner, Francesca Fragkoudi, Rebecca C. Levy, Kathryn Grasha, Ralf S. Klessen, J. M. Diederik Kruijssen, Nadine Neumayer, Francesca Pinna, Erik W. Rosolowsky, Rowan J. Smith, Yu-Hsuan Teng, Robin G. Tress, Elizabeth J. Watkins

Accepted in MNRAS

Galactic bars can drive cold gas inflows towards the centres of galaxies. The gas transport happens primarily through the so-called bar ``dust lanes'', which connect the galactic disc at kpc scales to the nuclear rings at hundreds of pc scales much like two gigantic galactic rivers. Once in the ring, the gas can fuel star formation activity, galactic outflows, and central supermassive black holes. Measuring the mass inflow rates is therefore important to understanding the mass/energy budget and evolution of galactic nuclei. In this work, we use CO datacubes from the PHANGS-ALMA survey and a simple geometrical method to measure the bar-driven mass inflow rate onto the nuclear ring of the barred galaxy NGC~1097. The method assumes that the gas velocity in the bar lanes is parallel to the lanes in the frame co-rotating with the bar, and allows one to derive the inflow rates from sufficiently sensitive and resolved position-position-velocity diagrams if the bar pattern speed and galaxy orientations are known. We find an inflow rate of $\dot{M}=(3.0 \pm 2.1)\, \rm M_\odot\, yr^{-1}$ averaged over a time span of 40 Myr, which varies by a factor of a few over timescales of $\sim$10 Myr. Most of the inflow appears to be consumed by star formation in the ring which is currently occurring at a rate of ${\rm SFR}\simeq~1.8$-$2 \rm M_\odot\, yr^{-1}$, suggesting that the inflow is causally controlling the star formation rate in the ring as a function of time.

Joanne L. Pledger, Michael M. Shara

5 pages, 3 figures, 1 table, submitted to ApJL

Stellar evolution theory predicts multiple pathways to the explosive deaths of stars as supernovae. Locating and characterizing the progenitors of well-studied supernovae is important to constrain the theory, and to justify and design future surveys to improve on progenitor detections. Here we report the serendipitous pre-explosion imaging, by the Hubble Space Telescope, of SN2023ixf, one of the nearest extragalactic supernovae ever discovered, in the galaxy M101. The extremely red color and absolute magnitude M(F814W)=-5.42+/-0.06mag suggest that the progenitor was a red supergiant and comparison with stellar evolutionary isochrones suggests a mass of ~12M_Sun.

Bruno L. Canto Martins, Yuri S. Messias, Maria I. Arruda Gonçalves, Izan C. Leão, Roseane L. Gomes, Lorenza F. Barraza, Dasaev O. Fontinele, José R. De Medeiros

15 pages, 1 figure in main paper, 6 supplementary figures. Published in Nature Astronomy, May 2023

Star-planet interactions play, among other things, a crucial role in planetary orbital configurations by circularizing orbits, aligning the star and planet spin and synchronizing stellar rotation with orbital motions. This is especially true for innermost giant planets, which can be schematized as binary systems with a very large mass ratio. Despite a few examples where spin-orbit synchronization has been obtained, there is no demographic study on synchronous regimes in those systems yet. Here we use a sample of 1,055 stars with innermost planet companions to show the existence of three observational loci of star-planet synchronization regimes. Two of them have dominant fractions of subsynchronous and supersynchronous star-planet systems, and a third less populated regime of potentially synchronized systems. No synchronous star-planet system with a period higher than 40 days has been detected yet. This landscape is different from eclipsing binary systems, most of which are synchronized. We suggest that planets in a stable asynchronous spin state belonging to star-planet systems in a supersynchronized regime offer the most favourable conditions for habitability.

Alvio Renzini

Four pages, no figures, submitted to MNRAS on May 22, 2023

The mere existence of multiple stellar generations in Milky Way globular clusters indicates that each generation was unable to stop star formation, that instead persisted unimpeded for several million years. This evidence argues for an extended stage of star formation within a forming globular cluster, during which stellar feedback was substantially ineffective and the nascent globular cluster was able to accrete processed gas from its surrounding, and efficiently convert it into successive stellar generations. It has been argued that such delayed feedback results from core collapse in most massive stars failing to trigger an energetic supernova explosion, but rather leading directly to black hole formation. Thus, globular clusters offer a concrete phenomenological example for the lack of feedback in young starbursts, an option that has been widely advocated to account for the unexpected abundance of UV-luminous galaxies at z = 9-16, as revealed by JWST observations. The paper is meant to attract attention to this opportunity for a synergic cooperation of globular cluster and high redshift research.

Sicong Huang, Nico Cappelluti, Massimiliano Galeazzi, Anjali Gupta, Wenhao Liu, Eugenio Ursino, Tomykkutty J. Velliyedathu

18 pages, 13 figures, 5 tables

We studied the spectral signature of different components of the Diffuse X-ray Background (DXB), including Local Hot Bubble (LHB), Solar Wind Charge Exchange (SWCX), Galactic Halo, and typically unresolved point sources (galaxies and AGN), in the direction of the Chandra Deep Field South (CDFS) using the 4 Ms XMM-Newton survey and Chandra 4 Ms Source Catalog. In this paper, we present our results showing how the different components contribute to the DXB below 1 keV. In particular, we have found that ~6% of the emission at 3/4 keV (all-sky average value ~ 3$\times10^{-3}$ cm$^{-6}$pc), which is typically associated with Galactic Halo (GH) and Circum-galactic medium (CGM) is, in fact, due to emission from typically unresolved galaxies. We will discuss the effect that this has on our understanding of GH and CGM, and to our understanding of the missing CGM baryons.

M. Patel, B. P. Gompertz, P. T. O'Brien, G. P. Lamb, R. L. C. Starling, P. A Evans, L. Amati, A. J. Levan, M. Nicholl, J. Lyman, K. Ackley, M. J. Dyer, K. Ulaczyk, D. Steeghs, D. K. Galloway, V. S. Dhillon, G. Ramsay, K. Noysena, R. Kotak, R. P. Breton, L. K. Nuttall, E. Palle, D. Pollacco

15 pages, 4 figures

GRB 201015A is a peculiarly low luminosity, spectrally soft gamma-ray burst (GRB), with $T_{\rm 90} = 9.8 \pm 3.5$ s (time interval of detection of 90\% of photons from the GRB), and an associated supernova (likely to be type Ic or Ic-BL). GRB 201015A has an isotropic energy $E_{\gamma,\rm iso} = 1.75 ^{+0.60} _{-0.53} \times 10^{50}$ erg, and photon index $\Gamma = 3.00 ^{+0.50} _{-0.42}$ (15-150 keV). It follows the Amati relation, a correlation between $E_{\gamma,\rm iso}$ and spectral peak energy $E_{\rm p}$ followed by long GRBs. It appears exceptionally soft based on $\Gamma$, the hardness ratio of HR = $0.47 \pm 0.24$, and low-$E_{\rm p}$, so we have compared it to other GRBs sharing these properties. These events can be explained by shock breakout, poorly collimated jets, and off-axis viewing. Follow-up observations of the afterglow taken in the X-ray, optical, and radio, reveal a surprisingly late flattening in the X-ray from $t = (2.61 \pm 1.27)\times 10^4$ s to $t = 1.67 ^{+1.14} _{-0.65} \times 10^6$ s. We fit the data to closure relations describing the synchrotron emission, finding the electron spectral index to be $p = 2.42 ^{+0.44} _{-0.30}$, and evidence of late-time energy injection with coefficient $q = 0.24 ^{+0.24} _{-0.18}$. The jet half opening angle lower limit ($\theta_{j} \ge 16^{\circ}$) is inferred from the non-detection of a jet break. The launch of SVOM and Einstein Probe in 2023, should enable detection of more low luminosity events like this, providing a fuller picture of the variety of GRBs.

F. Stoppa, R. Ruiz de Austri, P. Vreeswijk, S. Bhattacharyya, S. Caron, S. Bloemen, G. Zaharijas, G. Principe, V. Vodeb, E. Cator, G. Nelemans

Aims. In astronomy, machine learning has demonstrated success in various tasks such as source localization, classification, anomaly detection, and segmentation. However, feature regression remains an area with room for improvement. We aim to design a network that can accurately estimate sources' features and their uncertainties from single-band image cutouts, given the approximated locations of the sources provided by the previously developed code ASID-L or other external catalogues. Methods. The algorithm presented here, AutoSourceID-FeatureExtractor (ASID-FE), uses single-band cutouts of 32x32 pixels around the localized sources to estimate flux, sub-pixel centre coordinates, and their uncertainties. ASID-FE employs what we call a TS-MVE, a Two-Step Mean Variance Estimator approach to first estimate the features and then their uncertainties without the need for additional information, e.g. Point Spread Function (PSF). Results. We show that ASID-FE, trained on synthetic images from the MeerLICHT telescope, can predict more accurate features with respect to similar codes like SourceExtractor and that the two-step method can estimate well-calibrated uncertainties that are better behaved compared to similar methods that use deep ensembles of simple MVE networks. Finally, we evaluate the model on real images from the MeerLICHT telescope and the Zwicky Transients Facility (ZTF) to test its Transfer Learning abilities.

M. C. Baglio, F. Coti Zelati, S. Campana, G. Busquet, P. D'Avanzo, S. Giarratana, M. Giroletti, F. Ambrosino, S. Crespi, A. Miraval Zanon, X. Hou, D. Li, J. Li, P. Wang, D. M. Russell, D. F. Torres, K. Alabarta, P. Casella, S. Covino, D. M. Bramich, D. de Martino, M. Méndez, S. E. Motta, A. Papitto, P. Saikia, F. Vincentelli

25 pages, 12 figures, 9 tables. Submitted to Astronomy and Astrophysics

Transitional millisecond pulsars are an emerging class of sources linking low-mass X-ray binaries to millisecond radio pulsars in binary systems. These pulsars alternate between a radio pulsar state and an active low-luminosity X-ray disc state. During the active state, these sources exhibit two distinct emission modes (high and low) that alternate unpredictably, abruptly, and incessantly. X-ray to optical pulsations are observed only during the high mode. Knowledge of the root reason for this puzzling behaviour remains elusive. This paper presents the results of the most extensive multi-wavelength campaign ever conducted on the transitional pulsar prototype, PSR J1023+0038, covering from radio to X-rays. The campaign was carried out over two nights in June 2021, and involved 12 different telescopes and instruments including XMM-Newton, HST, VLT/FORS2 (in polarimetric mode), ALMA, VLA and FAST. By modelling the broadband spectral energy distributions in both emission modes, we show that the mode switches are caused by changes in the innermost region of the accretion disc. These changes trigger the emission of discrete mass ejections, which occur on top of a compact jet, as testified by the detection of at least one short-duration millimetre flare with ALMA at the high-to-low mode switch. A subsequent re-enshrouding of the pulsar completes the scenario behind the mode switches.

Rebecca G. Martin

Accepted for publication in MNRAS Letters

Superorbital periods are observed in the optical light curves of many Be/X-ray binaries yet their origin has remained somewhat elusive. We suggest that precession of the spin axis of the Be star can drive superorbital periods, particularly for short orbital period binaries. We consider the short orbital period ($P_{\rm orb}=16.6\,\rm day$) and highly eccentric ($e_{\rm b}=0.72$) Be/X-ray binary A0538-66 that has a superorbital period of $421\,\rm day$. First we show that the spin axis precession timescale is about twice the observed superorbital period. Then, with hydrodynamic simulations we show that the Be star decretion disc can remain locked to the equator of the precessing Be star. At each periastron passage of the neutron star, material is accreted into a disc around the neutron star. The neutron star disc nodally precesses on the same timescale as the Be star disc and therefore both discs can contribute to the observed superorbital period. For wider and less eccentric binary systems, the Be star disc can have a larger radial extent and more complex behaviour is expected as a result of disc warping and breaking.

Ryan M. Lau, Jason Wang, Matthew J. Hankins, Thayne Currie, Vincent Deo, Izumi Endo, Olivier Guyon, Yinuo Han, Anthony P. Jones, Nemanja Jovanovic, Julien Lozi, Anthony F. J. Moffat, Takashi Onaka, Garreth Ruane, Andreas A. C. Sander, Samaporn Tinyanont, Peter G. Tuthill, Gerd Weigelt, Peredur M. Williams, Sebastien Vievard

21 pages, 8 figures, Accepted for publication in ApJ

Wolf-Rayet (WR) 140 is the archetypal periodic dust-forming colliding-wind binary that hosts a carbon-rich WR (WC) star and an O-star companion with an orbital period of 7.93 years and an orbital eccentricity of 0.9. Throughout the past several decades, multiple dust-formation episodes from WR 140 have been observed that are linked to the binary orbit and occur near the time of periastron passage. Given its predictable dust-formation episodes, WR 140 presents an ideal astrophysical laboratory for investigating the formation and evolution of dust in the hostile environment around a massive binary system. In this paper, we present near- and mid-infrared (IR) spectroscopic and imaging observations of WR 140 with Subaru/SCExAO+CHARIS, Keck/NIRC2+PyWFS, and Subaru/COMICS taken between 2020 June and Sept that resolve the circumstellar dust emission linked to its most recent dust-formation episode in 2016 Dec. Our spectral energy distribution (SED) analysis of WR 140's resolved circumstellar dust emission reveals the presence of a hot ($T_\mathrm{d}\sim1000$ K) near-IR dust component that is co-spatial with the previously known and cooler ($T_\mathrm{d}\sim500$ K) mid-IR dust component composed of $300-500$ {\AA}-sized dust grains. We attribute the hot near-IR dust emission to the presence of nano-sized ("nanodust") grains and suggest they were formed from grain-grain collisions or the rotational disruption of the larger grain size population by radiative torques in the strong radiation field from the central binary. Lastly, we speculate on the astrophysical implications of nanodust formation around colliding-wind WC binaries, which may present an early source of carbonaceous nanodust in the interstellar medium.

Aida Wofford, Andrés Sixtos, Stephane Charlot, Gustavo Bruzual, Fergus Cullen, Thomas M. Stanton, Svea Hernández, Linda J. Smith, Matthew Hayes

17 pages, 17 figures, accepted in MNRAS

Super star cluster (SSC) A1 (3.1E5 Msun) in NGC 3125 has one of the strongest (EW = 4.6 +/- 0.5 Ang) broad (FWHM = 1131 +\- 40 km/s) He II 1640 emission lines in the nearby Universe and constitutes an important template for interpreting observations of extreme He II emitters out to redshifts of z = 2-3. We use Cosmic Origins Spectrograph (COS) observations of A1 to show that there is no significant contamination of the He II line with nebular emission and that the line is redshifted by 121 +/-17 km/s relative to ISM lines. We compare the COS G130M + G160M observations of A1 to recent binary BPASS and single-star Charlot & Bruzual (C&B) simple stellar population (SSP) models with Very Massive Stars (VMS) of up to 300 Msun. We suggest why BPASS models fail to reproduce A1's He II emission. On the other hand, a C&B model with Z = 0.008, age = 2.2 Myr, and VMS approaching the Eddington limit provides an excellent fit to the He II emission and fits reasonably well C III 1175, N V 1238,1241, and C IV 1548, 1551. We present O V 1371 line-profile predictions showing that this line constitutes an important tracer of youth and VMS in galaxies. Finally, we discuss the presence of VMS in CDFS131717, a highly star-forming low-metallicity galaxy located at z = 3.071, which has a tentative detection of O V absorption and strong broad He II emission. These features are rare and hint to the presence of short-lived VMS in the galaxy. Our results show the effect of the latest developments of stellar wind theory and the importance of accounting for VMS in models.

Wuhyun Sohn, James R. Fergusson, E. P. S. Shellard

35 pages, 12 figures, public codes at this https URL and this https URL

We present a new independent pipeline for the CMB bispectrum estimation of primordial non-Gaussianity and release a public code for constraining bispectrum shapes of interest based on the Planck 2018 temperature and polarization data. The estimator combines the strengths of the conventional KSW and Modal estimators at the cost of increased computational complexity, which has been made manageable through intensive algorithmic and implementation optimization. We also detail some methodological advances in numerical integration over a tetrapyd - domain where the bispectrum is defined on - via new quadrature rules. The pipeline has been validated both internally and against Planck. As a proof-of-concept example, we constrain some highly oscillatory models that were out of reach in conventional analyses using a targeted basis with a fixed oscillation frequency, and no significant evidence for primordial non-Gaussianity of these shapes is found. The methodology and code developed in this work will be directly applicable to future surveys where we expect a notable boost in sensitivity.

A. D. Cameron, M. Bailes, D. J. Champion, P. C. C. Freire, M. Kramer, M. A. McLaughlin, C. Ng, A. Possenti, A. Ridolfi, T. M. Tauris, H. M. Wahl, N. Wex

23 pages, 16 figures, 7 tables

PSR J1757$-$1854 is one of the most relativistic double neutron star binary systems known in our Galaxy, with an orbital period of $P_\text{b}=4.4\,\text{hr}$ and an orbital eccentricity of $e=0.61$. As such, it has promised to be an outstanding laboratory for conducting tests of relativistic gravity. We present the results of a 6-yr campaign with the 100-m Green Bank and 64-m Parkes radio telescopes, designed to capitalise on this potential. We identify secular changes in the profile morphology and polarisation of PSR J1757$-$1854, confirming the presence of geodetic precession and allowing the constraint of viewing geometry solutions consistent with General Relativity. We also update PSR J1757$-$1854's timing, including new constraints of the pulsar's proper motion, post-Keplerian parameters and component masses. We conclude that the radiative test of gravity provided by PSR J1757$-$1854 is fundamentally limited to a precision of 0.3 per cent due to the pulsar's unknown distance. A search for pulsations from the companion neutron star is also described, with negative results. We provide an updated evaluation of the system's evolutionary history, finding strong support for a large kick velocity of $w\ge280\,\text{km s}^{-1}$ following the second progenitor supernova. Finally, we reassess PSR J1757$-$1854's potential to provide new relativistic tests of gravity. We conclude that a 3-$\sigma$ constraint of the change in the projected semi-major axis ($\dot{x}$) associated with Lense-Thirring precession is expected no earlier than 2031. Meanwhile, we anticipate a 3-$\sigma$ measurement of the relativistic orbital deformation parameter $\delta_\theta$ as soon as 2026.

Jean-Marie Malherbe, Florence Cornu, Isabelle Bualé

arXiv admin note: text overlap with arXiv:2301.11105

Systematic observations of the chromosphere and the photosphere started in Meudon Observatory 115 years ago with Deslandres spectroheliograph. An exceptional collection of more than 100 000 monochromatic images in CaII K and H$\alpha$ spanning more than 10 solar cycles is proposed to the international community by the BASS2000 solar database. We started in 2023 a ''PRO-AM'' collaboration between professional and amateur astronomers with the Solar Explorer (SOLEX), a compact and high quality spectroheliograph designed by Christian Buil, in order to record images every day, and several times per day, owing to tens of observing stations in various places. This paper summarizes the scientific objectives and provides practical and technical information to amateurs willing to join the observing network.

Ian D. Roberts, Toby Brown, Nikki Zabel, Christine D. Wilson, Aeree Chung, Laura C. Parker, Dhruv Bisaria, Alessandro Boselli, Barbara Catinella, Ryan Chown, Luca Cortese, Timothy A. Davis, Sara Ellison, Maria Jesus Jimenez-Donaire, Bumhyun Lee, Rory Smith, Kristine Spekkens, Adam R.H. Stevens, Mallory Thorp, Vincente Villanueva, Adam B. Watts, Charlotte Welker, Hyein Yoon

15 pages, 8 figures, 1 table, accepted for publication in A&A

We analyze cold-gas distributions in Virgo cluster galaxies using resolved CO(2-1) (tracing molecular hydrogen, H2) and HI observations from the Virgo Environment Traced In CO (VERTICO) and the VLA Imaging of Virgo in Atomic Gas (VIVA) surveys. From a theoretical perspective, it is expected that environmental processes in clusters will have a stronger influence on diffuse atomic gas compared to the relatively dense molecular gas component, and that these environmental perturbations can compress the cold interstellar medium in cluster galaxies leading to elevated star formation. In this work we observationally test these predictions for star-forming satellite galaxies within the Virgo cluster. We divide our Virgo galaxy sample into HI-normal, HI-tailed, and HI-truncated classes and show, unsurprisingly, that the HI-tailed galaxies have the largest quantitative HI asymmetries. We also compare to a control sample of non-cluster galaxies and find that Virgo galaxies, on average, have HI asymmetries that are 40 +/- 10 per cent larger than the control. There is less separation between control, HI-normal, HI-tailed, and HI-truncated galaxies in terms of H2 asymmetries, and on average, Virgo galaxies have H2 asymmetries that are only marginally (20 +/- 10 per cent) larger than the control sample. We find a weak correlation between HI and H2 asymmetries over our entire sample, but a stronger correlation for those specific galaxies being strongly impacted by environmental perturbations. Finally, we divide the discs of the HI-tailed Virgo galaxies into a leading half and trailing half according to the observed tail direction. We find evidence for excess molecular gas mass on the leading halves of the disc. This excess molecular gas on the leading half is accompanied by an excess in star formation rate such that the depletion time is, on average, unchanged.

Jeremy L. Smallwood

10 pages, 8 figures, accepted for publication in MNRAS

In light of the recent confirmation of an eccentric orbit giant planet, $\beta$ Pic c, I revisit the formation and evolution of the warped debris disc in the system. $\beta$ Pic c is interior to $\beta$ Pic b, and the debris disc is exterior to both planets. Previous $N$-body simulations have shown that $\beta$ Pic b is responsible for exciting the inclination of the debris disc. With hydrodynamical simulations, I model a protoplanetary gas disc misaligned with the planets. I find that the gas disc does not exhibit significant long lasting inclination excitation from the planets even for the observed disc size. The warp that is excited by the planets propagates through the entire disc with a timescale much less than the gas disc lifetime. Therefore, the observed warp in the debris disc must be produced after the gas disc has dispersed. With analytical secular theory calculations, I show that two secular resonances are exterior to $\beta$ Pic b, located at $\sim 20\, \rm au$ and $\sim 25\, \rm au$. This agrees with my $N$-body simulations that show that these secular resonances shape the inner edge of the $\beta$ Pic debris disc at a radius that agrees with observations.

M. Muñoz-Echeverría, J. F. Macías-Pérez, E. Artis, W. Cui, D. de Andres, F. De Luca, M. De Petris, A. Ferragamo, C. Giocoli, C. Hanser, F. Mayet, M. Meneghetti, A. Moyer, A. Paliwal, L. Perotto, E. Rasia, G. Yepes

The determination of the mass of galaxy clusters from observations is subject to systematic uncertainties. Beyond the errors due to instrumental and observational systematic effects, in this work we investigate the bias introduced by modelling assumptions. In particular, we consider the reconstruction of the mass of galaxy clusters from convergence maps employing spherical mass density models. We make use of The Three Hundred simulations, selecting clusters in the same redshift and mass range as the NIKA2 Sunyaev-Zel'dovich Large Program sample: $3 \leq M_{500}/ 10^{14} \mathrm{M}_{\odot} \leq 10$ and $0.5 \leq z \leq 0.9$. We study different modelling and intrinsic uncertainties that should be accounted for when using the single cluster mass estimates for scaling relations. We confirm that the orientation of clusters and the radial ranges considered for the fit have an important impact on the mass bias. The effect of the projection adds uncertainties to the order of $10\%$ to $14\%$ to the mass estimates. We also find that the scatter from cluster to cluster in the mass bias when using spherical mass models is less than $20\%$ of the true mass of the clusters.

M. Glowacki, K. Lee-Waddell, A. T. Deller, N. Deg, A. C. Gordon, J. A. Grundy, L. Marnoch, A. X. Shen, S. D. Ryder, R. M. Shannon, O. I. Wong, H. Dénes, B. S. Koribalski, C. Murugeshan, J. Rhee, T. Westmeier, S. Bhandari, A. Bosma, B. W. Holwerda, J. X. Prochaska

13 pages, 5 figures. Published in ApJ

We report on the commensal ASKAP detection of a fast radio burst (FRB), FRB20211127I, and the detection of neutral hydrogen (HI) emission in the FRB host galaxy, WALLABYJ131913-185018 (hereafter W13-18). This collaboration between the CRAFT and WALLABY survey teams marks the fifth, and most distant, FRB host galaxy detected in HI, not including the Milky Way. We find that W13-18 has a HI mass of $M_{\rm HI}$ = 6.5 $\times$ 10$^{9}$ M$_{\odot}$, a HI-to-stellar mass ratio of 2.17, and coincides with a continuum radio source of flux density at 1.4 GHz of 1.3 mJy. The HI global spectrum of W13-18 appears to be asymmetric, albeit the HI observation has a low S/N, and the galaxy itself appears modestly undisturbed. These properties are compared to the early literature of HI emission detected in other FRB hosts to date, where either the HI global spectra were strongly asymmetric, or there were clearly disrupted HI intensity map distributions. W13-18 lacks sufficient S/N to determine whether it is significantly less asymmetric in its HI distribution than previous examples of FRB host galaxies. However, there are no strong signs of a major interaction in the HI or optical image of the host galaxy that would stimulate a burst of star formation and hence the production of putative FRB progenitors related to massive stars and their compact remnants.

Z.X. Ling, X.J. Sun, C. Zhang, S.L. Sun, G. Jin, S.N. Zhang, X.F. Zhang, J.B. Chang, F.S. Chen, Y.F. Chen, Z.W. Cheng, W. Fu, Y.X. Han, H. Li, J.F. Li, Y. Li, Z.D. Li, P.R. Liu, Y.H. Lv, X.H. Ma, Y.J. Tang, C.B. Wang, R.J. Xie, Y.L. Xue, A.L. Yan, Q. Zhang, C.Y. Bao, H.B. Cai, H.Q. Cheng, C.Z. Cui, Y.F. Dai, D.W. Fan, H.B. Hu, J.W. Hu, M.H. Huang, Z.Q. Jia, C.C. Jin, D.Y. Li, J.Q. Li, H.Y. Liu, M.J. Liu, Y. Liu, H.W. Pan, Y.L. Qiu, M. Sugizaki, H. Sun, W.X. Wang, Y.L. Wang, Q.Y. Wu, X.P. Xu, Y.F. Xu, H.N. Yang, X. Yang, B. Zhang, M. Zhang, W.D. Zhang, Z. Zhang, D.H. Zhao, X.Q. Cong, B.W. Jiang, L.H. Li, X.B. Qiu, J.N. Sun, D.T. Su, J. Wang, C. Wu, Z. Xu, X.M. Yang, S.K. Zhang, Z. Zhang, N. Zhang, Y.F. Zhu, H.Y. Ban, X.Z. Bi, Z.M. Cai, W. Chen, X. Chen, Y.H. Chen, Y. Cui, X.L. Duan, Z.G Feng, et al. (45 additional authors not shown)

Accepted by RAA

The Lobster Eye Imager for Astronomy (LEIA), a pathfinder of the Wide-field X-ray Telescope of the Einstein Probe (EP) mission, was successfully launched onboard the SATech-01 satellite of the Chinese Academy of Sciences on 27 July 2022. In this paper, we introduce the design and on-ground test results of the LEIA instrument. Using state-of-the-art Micro-Pore Optics (MPO), a wide field-of-view (FoV) of 346 square degrees (18.6 degrees * 18.6 degrees) of the X-ray imager is realized. An optical assembly composed of 36 MPO chips is used to focus incident X-ray photons, and four large-format complementary metal-oxide semiconductor (CMOS) sensors, each of 6 cm * 6 cm, are used as the focal plane detectors. The instrument has an angular resolution of 4 - 8 arcmin (in FWHM) for the central focal spot of the point spread function, and an effective area of 2 - 3 cm2 at 1 keV in essentially all the directions within the field of view. The detection passband is 0.5 - 4 keV in the soft X-rays and the sensitivity is 2 - 3 * 10-11 erg s-1 cm-2 (about 1 mini-Crab) at 1,000 second observation. The total weight of LEIA is 56 kg and the power is 85 W. The satellite, with a design lifetime of 2 years, operates in a Sun-synchronous orbit of 500 km with an orbital period of 95 minutes. LEIA is paving the way for future missions by verifying in flight the technologies of both novel focusing imaging optics and CMOS sensors for X-ray observation, and by optimizing the working setups of the instrumental parameters. In addition, LEIA is able to carry out scientific observations to find new transients and to monitor known sources in the soft X-ray band, albeit limited useful observing time available.

Luis Guerrero-Mendez, Anxo Lema-Saavedra, Elena Jimenez, Antonio Fernandez-Ramos, Emilio Martinez-Nunez

Our automated reaction discovery program, AutoMeKin, has been utilized to investigate the formation of glycolonitrile (HOCH$_{2}$CN) in the gas phase under the low temperatures of the interstellar medium (ISM). The feasibility of a proposed pathway depends on the absence of barriers above the energy of reactants and the availability of the suggested precursors in the ISM. Based on these criteria, several radical-radical reactions and a radical-molecule reaction have been identified as viable formation routes in the ISM. Among the radical-radical reactions, OH+CH$_{2}$CN appears to be the most relevant, considering the energy of the radicals and its ability to produce glycolonitrile in a single step. However, our analysis reveals that this reaction produces hydrogen isocyanide (HNC) and formaldehyde (CH$_{2}$O), with rate coefficients ranging from (7.3-11.5)$\times$10$^{-10}$ cm$^3$ molecule$^{-1}$ s$^{-1}$ across the temperature range of 10-150 K. This finding is particularly interesing given the persistently unexplained overabundance of hydrogen isocyanide in the ISM. Among the radical-molecule reactions investigated, the most promising one is OH+CH$_{2}$CNH, which forms glycolonitrile and atomic hydrogen with rate coefficients in the range (0.3-6.6)$\times$10$^{-10}$ cm$^3$ molecule$^{-1}$ s$^{-1}$ within the 10-150 K temperature range. Our calculations indicate that the formation of both hydrogen isocyanide and glycolonitrile is efficient under the harsh conditions of the ISM.

Tinatin Baratashvili, Christine Verbeke, Rony Keppens, Stefaan Poedts

17 pages, 9 figures, 4 tables, to appear in Sun and Geosphere

Coronal mass ejections (CMEs) are large eruptions close to the solar surface, where plasma is ejected outwards into space at large speeds. When directed towards Earth, they interfere with Earth's magnetic fields and cause strong geo-effective storms. In order to mitigate the potential damage, forecasting tools are implemented. Recently, a novel heliospheric modelling tool, Icarus, has been implemented, which exploits the open-source framework MPI-AMRVAC as its core MHD solver. This new model efficiently performs 3D MHD simulations of the solar wind and the evolution of interplanetary CMEs with the help of advanced techniques, such as adaptive mesh refinement and gradual radial grid stretching. The numerical methods applied in the simulations can have significant effects on the simulation results and on the efficiency of the model. In this study, the effect of different combinations of numerical schemes and slope limiters, for reconstructing edge-based variabes used in fluxes, is considered. We explore frequently exploited combinations from the available numerical schemes in MPI-AMRVAC: TVDLF, HLL and HLLC along with the slope limiters 'woodward', 'minmod', 'vanleer', and 'koren'. For analysis purposes, we selected one particular solar wind configuration and studied the influence on variables at 1 AU in the equatorial plane. The goal is to find the optimal combination to produce accurate results fast and in a robust way so that the model can be reliable for day-to-day use by space weather scientists. As a conclusion, the best result assessed with these two criteria is the combination of the TVDLF scheme with the 'woodward' limiter.

Waleed El Hanafy, Adel Awad

PdfLaTeX, 12 pages, 3 figures, 1 table, 1 appendix. To appear in ApJ

It has been shown that the nonminimal coupling between geometry and matter can provide models for massive compact Stars \citep{ElHanafy:2022kjl}, which are consistent with the conformal bound on the sound speed, $0\leq c_s^2 \leq c^2/3$, where the core density approaches a few times the nuclear saturation density. We impose the conformal sound speed upper bound constraint on Rastall's field equations of gravity, with Krori-Barua potentials in presence of an anisotropic fluid as a matter source, to estimate the radius of the most massive pulsar PSR J0952\textendash{0607} ever observed. For its measured mass $M = 2.35\pm 0.17\, M_\odot$, we obtain a radius $R=14.087 \pm 1.0186$~km as inferred by the model. We investigate possible connection between Rastall garvity and MIT bag model with an EoS, $p_r(\rho) \approx c_s^2\left(\rho - \rho_\text{s}\right)$, in the radial direction, with $c_s=c/\sqrt{3}$ and a surface density $\rho_\text{s}$ slightly above the nuclear saturation density $\rho_\text{nuc}=2.7\times 10^{14}$~g/cm$^3$. The corresponding mass\textendash{radius} diagram is in agreement with our estimated value of the radius and with astrophysical observations of other pulsars at 68\% C.L.

Alessandro Ursi, Nicolò Parmiggiani, Mauro Messerotti, Alberto Pellizzoni, Carlotta Pittori, Francesco Longo, Francesco Verrecchia, Andrea Argan, Andrea Bulgarelli, Marco Tavani, Patrizio Tempesta, Fabio D'Amico

22 pages, 10 figures

We report the Astrorivelatore Gamma ad Immagini LEggero (AGILE) observations of solar flares, detected by the on board anticoincidence system in the 80-200 keV energy range, from 2007 May 1st to 2022 August 31st. In more than 15 yr, AGILE detected 5003 X-ray, minute-lasting transients, compatible with a solar origin. A cross-correlation of these transients with the Geostationary Operational Environmental Satellites (GOES) official solar flare database allowed to associate an intensity class (i.e., B, C, M, or X) to 3572 of them, for which we investigated the main temporal and intensity parameters. The AGILE data clearly revealed the solar activity covering the last stages of the 23rd cycle, the whole 24th cycle, and the beginning of the current 25th cycle. In order to compare our results with other space missions operating in the high-energy range, we also analyzed the public lists of solar flares reported by RHESSI and Fermi Gamma-ray Burst Monitor. This catalog reports 1424 events not contained in the GOES official dataset, which, after statistical comparisons, are compatible with low-intensity, short-duration solar flares. Besides providing a further dataset of solar flares detected in the hard X-ray range, this study allowed to point out two main features: a longer persistence of the decay phase in the high-energy regime, with respect to the soft X-rays, and a tendency of the flare maximum to be reached earlier in the soft X-rays with respect to the hard X-rays. Both these aspects support a two-phase acceleration mechanism of electrons in the solar atmosphere.

M. Caramazza, B. Stelzer, E. Magaudda, St. Raetz, M. Güdel, S. Orlando, K. Poppenhäger

accepted for publication in Astronomy & Astrophysics (A&A)

We have embarked in a systematic study of the X-ray emission in a volume-limited sample of M dwarf stars, in order to explore the full range of activity levels present in their coronae and, thus, to understand the conditions in their outer atmospheres and their possible impact on the circumstellar environment. We identify in a recent catalog of the Gaia objects within 10 pc from the Sun all the stars with spectral type between M0 and M4, and search systematically for X-ray measurements of this sample. To this end, we use both archival data (from ROSAT, XMM-Newton, and from the ROentgen Survey with an Imaging Telescope Array (eROSITA) onboard the Russian Spektrum-Roentgen-Gamma mission) and our own dedicated XMM-Newton observations. To make inferences on the properties of the M dwarf corona we compare the range of their observed X-ray emission levels to the flux radiated by the Sun from different types of magnetic structures: coronal holes, background corona, active regions and cores of active regions. At the current state of our project, with more than 90\% of the 10pc M dwarf sample observed in X-rays, only GJ 745 A has no detection. With an upper limit luminosity of log Lx [erg/s] < 25.4 and an X-ray surface flux of log FX,SURF [erg/cm^2/s] < 3.6 GJ 745 A defines the lower boundary of the X-ray emission level of M dwarfs. Together with its companion GJ 745 B, GJ 745 A it is the only star in this volume-complete sample located in the range of FX,SURF that corresponds to the faintest solar coronal structures, the coronal holes. The ultra-low X-ray emission level of GJ 745 B (log Lx [erg/s] = 25.6 and log FX,SURF [erg/cm^2/s] = 3.8) is entirely attributed to flaring activity, indicating that, while its corona is dominated by coronal holes, at least one magnetically active structure is present and determines the total X-ray brightness and the coronal temperature of the star.

Recent observations in extreme-ultraviolet (EUV) wavelengths reveal an EUV late phase in some solar flares, which is characterized by a second peak in the warm coronal emissions (about 3 MK) occurring several tens of minutes to a few hours after the corresponding main flare peak. We aim to clarify the physical origin of an atypical plateau-like EUV late phase in an X1.8-class solar flare occurring on 2011 September 7 from active region (AR) 11283. We first characterize the plateau-like late phase using EUV Variability Experiment (EVE) full-disk integrated irradiance observations and Atmospheric Imaging Assembly (AIA) spatially-resolved imaging observations on board the Solar Dynamics Observatory (SDO). Then we perform a nonlinear force-free-field (NLFFF) extrapolation, from which a filament-hosting magnetic flux rope (MFR) is revealed. The eruption of the MFR is tracked both in the plane of the sky (POS) and along the line of sight (LOS) through visual inspection and spectral fitting, respectively. Finally, we carry out differential emission measure (DEM) analysis to explore the thermodynamics of the late-phase loops. The MFR shows a non-radial eruption from a fan-spine magnetic structure. The eruption of the MFR and its interaction with overlying arcades invoke multiple magnetic reconnections, which are responsible for the production of different groups of late-phase loops. Afterwards, the late-phase loops enter a long-lasting cooling stage, appearing sequentially in AIA passbands of decreasing response temperatures. Due to their different lengths, the different groups of late-phase loops cool down at different cooling rates, which makes their warm coronal emission peaks temporally separated from each other. Combing the emissions from all late-phase loops together, an elongated plateau-like late phase is formed.

Sunay Ibryamov, Gabriela Zidarova, Evgeni Semkov, Stoyanka Peneva

13 pages, 11 figures, 4 tables, accepted for publication in Research in Astronomy and Astrophysics (RAA)

This paper reports results from our long-term $BV(RI)_{c}$ photometric CCD observations of eight pre-main-sequence stars collected from June 2008 to October 2022. These stars are located in the young open cluster Trumpler 37, in the field of GM Cephei. The observational data indicate that all stars from our study exhibit variability in all-optical passbands, typical for young stars. In this paper, we describe and discuss the photometric behavior of the stars and the possible reasons for their variability. For two of the objects, we identified periodicity in their light variation.

Petrosian Vah/'e, Maria Giovanna Dainotti

6 pages, 4 figures of two panels

Bimodal distribution of the observed duration of gamma-ray bursts (GRBs) has led to two distinct progenitors; compact star mergers, either two neutron stars (NSs) or a NS and a black hole (BH), for short GRBs (SGRBs), and so-called collapsars for long GRBs (LGRBs). It is therefore expected that formation rate (FR) of LGRBs should be similar to the cosmic star formation rate (SFR), while that of SGRBs to be delayed relative to the SFR. The localization of some LGRBs in and around the star forming regions of host galaxies and some SGRBs away form such regions support this expectation. Another distinct feature of SGRBs is their association with gravitational wave (GW) sources and kilonovae. However, several independent investigations of the FRs of long and short bursts, using the Efron-Petrosian non-parametric method have shown a LGRB FR that is significantly larger than SFR at low redhift, and similar to the FR of SGRBs. In addition, recent discovery of association of a low redshift long GRB211211A with a kilonova raises doubt about its collapsar origin. In this letter we review these results and show that low redshift LGRBs could also have compact star mergers as progenitor increasing the expected rate of the GW sources and kilonovae significantly.

The common-spectrum process observed by pulsar-timing arrays is interpreted as stochastic gravitational wave backgrounds originating from various sources in the early Universe. Along with generating gravitational waves, we find energy density perturbations also arise with the sources such as bubble collisions and sound waves during first-order phase transitions, cosmic strings, domain walls, condensate fragmentation, and primordial curvature perturbations from inflation. These perturbations can lead to the formation of abundant ultracompact minihalos. Currently, the observational precision is inadequate for discriminating between different models. Then, ongoing and future astrophysical observations of ultracompact minihalos can help to distinguish and constrain the gravitational-wave sources in the nanohertz and $\mu$Hz bands.

A. Alonso-Herrero, S. Garcia-Burillo, M. Pereira-Santaella, T. Shimizu, F. Combes, E. K. S. Hicks, R. Davies, C. Ramos Almeida, I. Garcia-Bernete, S. F. Hoenig, N. A. Levenson, C. Packham, E. Bellocchi, L. K. Hunt, M. Imanishi, C. Ricci, P. Roche

Accepted for publication to A&A

We present new ALMA observations of the CO(3-2) transition and 854micron continuum at 0.06-0.3" resolution, together with new VLT/SINFONI observations of NGC7172. This is a luminous (bolometric luminosity of ~10^44 erg/s) Seyfert galaxy that belongs to the Galaxy Activity, Torus, and Outflow Survey (GATOS). The CO(3-2) observations reveal the presence of a highly inclined cold molecular gas ring with an approximate radius of 3-4"~540-720 pc, which is likely associated with an inner Lindblad resonance of a putative stellar bar. There are noncircular motions in the VLT/SINFONI [SiVI]1.96micron and H2 at 2.12micron, and ALMA CO(3-2) velocity fields. After subtracting the stellar velocity field, we detected [SiVI] blueshifted velocities of a few hundred km/s to the south of the AGN. They trace outflowing ionized gas outside the plane of the galaxy and out to projected distances of ~200 pc. The CO(3-2) position-velocity diagram along the kinematic minor axis displays noncircular motions with observed velocities of up to ~150 km/s. Assuming that these are taking place in the disk of the galaxy, the observed velocity signs imply that the molecular gas ring is not only rotating but also outflowing. We derived an integrated cold molecular gas mass outflow rate of ~40 Msun/yr for the ring. Using the 854micron map, we resolved a 32 pc radius torus with a gas mass of 8x10^5 Msun. These torus properties are similar to other Seyfert galaxies in the GATOS sample. We measured a decreased cold molecular gas concentration in the nuclear-torus region relative to the circumnuclear region when compared to other less luminous Seyfert galaxies. We conclude that the effects of AGN feedback in NGC7172, which are likely caused by the AGN wind and/or the moderate luminosity radio jet, are seen as a large-scale outflowing molecular gas ring and accompanying redistribution of molecular gas in the nuclear regions.

Anson Ka Long Yip, Patrick Chi-Kit Cheong, Tjonnie Guang Feng Li

12 pages, 4 figures

Strong magnetic fields make neutron stars potential sources of detectable electromagnetic and gravitational-wave signals. Hence, inferring these magnetic fields is critical to understand the emissions of neutron stars. However, due to the lack of direct observational evidence, the interior magnetic field configuration remains ambiguous. Here, for the first time, we show that the internal magnetic field strength along with the composition of a neutron star can be directly constrained by detecting the gravitational waves from the phase-transition-induced collapse of a magnetized neutron star. By dynamically simulating this collapsing event, we first find that the dominant peaks in the gravitational waveform are the fundamental $l=0$ quasi-radial $F$ mode and the fundamental $l=2$ quadrupolar $^2f$ mode. We next show that the maximum gravitational wave amplitude $|h|_\mathrm{max}$ increases with the maximum magnetic field strength of the interior toroidal field $\mathcal{B}_\mathrm{max}$ until the maximum rest-mass density at bounce $\rho_\mathrm{max,b}$ decreases due to the increasing $\mathcal{B}_\mathrm{max}$. We then demonstrated that the magnetic suppression of fundamental modes found in our previous work remains valid for the hybrid stars formed after the phase-transition-induced collapses. We finally show that measuring the frequency ratio between the two fundamental modes $f_{^2f}/f_{F}$ allows one to infer $\mathcal{B}_\mathrm{max}$ and the baryonic mass fraction of matter in the mixed phase $M_\mathrm{mp} / M_{0}$ of the resulting hybrid star. Consequently, taking $\mathcal{B}_\mathrm{max}$ and $M_\mathrm{mp} / M_{0}$ as examples, this work has demonstrated that much information inside neutron stars could be extracted similarly through measuring the oscillation modes of the stars.

Alessandra Fumagalli, Yodovina Piškur, Anže Slosar

14 pages, 7 figures

We present a new class of models that have potential to alleviate tensions present in the cosmological data today. We postulate variation in the sound horizon scale on super-horizon scales, i.e. on scales that are larger than that of the present observable low-redshift universe ($\gtrsim 1\,$Gpc) while at the same time smaller than the largest scales probed by the cosmic microwave background (CMB) ($\lesssim10\,$Gpc). In this scenario, CMB peaks are naturally smoothed as preferred by the Planck data, while at the same time the low-redshift baryon acoustic oscillation calibration is partially decoupled from the CMB. Taking super-horizon variations in baryon fraction as an example and using approximate modeling, we find improvement in the best fit Planck power spectrum model $\Delta \chi^2 \sim 6$ for one extra degree of freedom with the relevant extension parameter $10^3 \sigma_b = 2.12 \pm 0.50 $, implying about $10\%$ variations in baryon fraction across the universe. At the same time, $S_8$ drops by about 1 sigma, easing tension with weak lensing surveys. While $H_0$ increases in this model by about 1 sigma, this is insufficient to explain the Hubble tension in $\Lambda$CDM. Since the power of low redshift BAO is relaxed, we find that the combination of Planck 2018 data, eBOSS BAO data and Riess et al distance ladder Hubble parameter determination produces a satisfactory fit in the model with free dark energy equation of state. Such a fit, however, favors a phantom dark energy equation of state $w<-1$ at 2-3 sigma.

Inflationary cosmology has made significant strides in understanding the physics driving the rapid expansion of the early universe. However, many inflation models with diverse potential shapes present analysis, comparison, and classification challenges. In this paper, we propose a novel approach to tackle this issue. We introduce a general potential formula encompassing all inflationary potentials, whether single-field or multi-field, into a single mathematical framework. This formula establishes a unified framework for systematically classifying inflation models based on their potential functions. We showcase the efficacy of the general potential formula by successfully reproducing well-known inflation models, such as the Starobinsky potential and the Valley Hybrid Inflation model. Moreover, we derive general inflationary parameters, including the slow-roll parameters and power spectra, using the proposed formula. Our approach provides a versatile tool for classifying and studying various inflationary scenarios, simplifying the analysis and comparison of different models in the field of inflationary cosmology.

Auchère, F., Berghmans, D., Dumesnil, C., Halain, J.-P., Mercier, R., Rochus, P., Delmotte, F., François, S., Hermans, A., Hervier, V., Kraaikamp, E., Meltchakov, E., Morinaud, G., Philippon, A., Smith, P. J., Stegen, K., Verbeeck, C., Zhang, X. Y., Andretta, V., Abbo, L., Buchlin, E., Frassati, F., Gissot, S., Gyo, M., Harra, L., Jerse, G., Landini, F., Mierla, M., Nicula, B., Parenti, S., Renotte, E., Romoli, M., Russano, G., Sasso, C., Schühle, U., Schmutz, W., Soubrié, E., Susino, R., Teriaca, L., West, M., Zhukov, A. N

Most observations of the solar corona beyond 2 Rs consist of broadband visible light imagery from coronagraphs. The associated diagnostics mainly consist of kinematics and derivations of the electron number density. While the measurement of the properties of emission lines can provide crucial additional diagnostics of the coronal plasma (temperatures, velocities, abundances, etc.), these observations are comparatively rare. In visible wavelengths, observations at these heights are limited to total eclipses. In the VUV range, very few additional observations have been achieved since the pioneering results of UVCS. One of the objectives of the Full Sun Imager (FSI) channel of the EUI telescope on board the Solar Orbiter mission has been to provide very wide field-of-view EUV diagnostics of the morphology and dynamics of the solar atmosphere in temperature regimes that are typical of the lower transition region and of the corona. FSI carries out observations in two narrowbands of the EUV spectrum centered on 17.4 nm and 30.4 nm that are dominated, respectively, by lines of Fe IX/X (formed in the corona around 1 MK) and by the resonance line of He II (formed around 80 kK in the lower transition region). Unlike previous EUV imagers, FSI includes a moveable occulting disk that can be inserted in the optical path to reduce the amount of instrumental stray light to a minimum. FSI detects signals at 17.4 nm up to the edge of its FOV (7~Rs), which is about twice further than was previously possible. Comparisons with observations by the LASCO and Metis coronagraphs confirm the presence of morphological similarities and differences between the broadband visible light and EUV emissions, as documented on the basis of prior eclipse and space-based observations. The very-wide-field observations of FSI are paving the way for future dedicated instruments.

Valery F. Suleimanov, Sofia V. Forsblom, Sergey S. Tsygankov, Juri Poutanen, Victor Doroshenko, Rosalia Doroshenko, Fiamma Capitanio, Alessandro Di Marco, Denis González-Caniulef, Jeremy Heyl, Fabio La Monaca, Alexander A. Lutovinov, Sergey V. Molkov, Christian Malacaria, Alexander A. Mushtukov, Andrey E. Shtykovsky, Iván Agudo, Lucio A. Antonelli, Matteo Bachetti, Luca Baldini, Wayne H. Baumgartner, Ronaldo Bellazzini, Stefano Bianchi, Stephen D. Bongiorno, Raffaella Bonino, Alessandro Brez, Niccolò Bucciantini, Simone Castellano, Elisabetta Cavazzuti, Chien-Ting Chen, Stefano Ciprini, Enrico Costa, Alessandra De Rosa, Ettore Del Monte, Laura Di Gesu, Niccolò Di Lalla, Immacolata Donnarumma, Michal Dovčiak, Steven R. Ehlert, Teruaki Enoto, Yuri Evangelista, Sergio Fabiani, et al. (63 additional authors not shown)

10 pages, 10 figures, submitted to A&A

The phase- and energy-resolved polarization measurements of accreting X-ray pulsars (XRPs) allow us to test different theoretical models of their emission, as well as to provide an avenue to determine the emission region geometry. We present the results of the observations of the XRP GX 301-2 performed with the Imaging X-ray Polarimetry Explorer (IXPE). GX 301-2 is a persistent XRP with one of the longest known spin periods of ~680 s. A massive hyper-giant companion star Wray 977 supplies mass to the neutron star via powerful stellar winds. We do not detect significant polarization in the phase-averaged data using spectro-polarimetric analysis, with the upper limit on the polarization degree (PD) of 2.3% (99% confidence level). Using the phase-resolved spectro-polarimetric analysis we get a significant detection of polarization (above 99% c.l.) in two out of nine phase bins and marginal detection in three bins, with a PD ranging between ~3% and ~10%, and a polarization angle varying in a very wide range from ~0 deg to ~160 deg. Using the rotating vector model we obtain constraints on the pulsar geometry using both phase-binned and unbinned analysis getting excellent agreement. Finally, we discuss possible reasons for a low observed polarization in GX 301-2.

J. Cernicharo, B. Tercero, N. Marcelino, M. Agundez, P. de Vicente

Accepted for publication in A&A Letters

We present a highly sensitive 2D line survey of TMC-1 obtained with the Yebes 40m radio telescope in the Q-band (31.13-49.53 GHz). These maps cover a region of 320 arcsec x 320 arcsec centred on the position of the QUIJOTE line survey with a spatial sampling of 20 arcsec. The region covering 240 arcsec x 240 arcsec, where a longer integration time was used, shows a homogenous sensitivity of 2-4 mK across the band. We present in this work the first determination of the spatial extent of benzonitrile (C6H5CN), which follows that of cyanopolyynes rather well, but differs significantly from that of the radicals CnH and CnN. We definitively conclude that aromatic species in TMC-1 are formed from chemical reactions involving smaller species in the densest zones of the cloud.

J. D. Wagenveld, H-R. Klöckner, D. J. Schwarz

14 pages, 11 figures. Accepted for publication in Astronomy & Astrophysics

The cosmic radio dipole is an anisotropy in the number counts of radio sources, analogous to the dipole seen in the cosmic microwave background (CMB). Measurements of source counts of large radio surveys have shown that though the radio dipole is generally consistent in direction with the CMB dipole, the amplitudes are in tension. These observations present an intriguing puzzle as to the cause of this discrepancy, with a true anisotropy breaking with the assumptions of the cosmological principle, invalidating the most common cosmological models that are built on these assumptions. We present a novel set of Bayesian estimators to determine the cosmic radio dipole and compare the results with commonly used methods on the Rapid ASKAP Continuum Survey (RACS) and the NRAO VLA Sky Survey (NVSS) radio surveys. In addition, we adapt the Bayesian estimators to take into account systematic effects known to affect such large radio surveys, folding information such as the local noise floor or array configuration directly into the parameter estimation. The enhancement of these estimators allows us to greatly increase the amount of sources used in the parameter estimation, yielding tighter constraints on the cosmic radio dipole estimation than previously achieved with NVSS and RACS. We extend the estimators further to work on multiple catalogues simultaneously, leading to a combined parameter estimation using both NVSS and RACS. The result is a dipole estimate that perfectly aligns with the CMB dipole in terms of direction but with an amplitude that is three times as large, and a significance of 4.8$\sigma$. This new dipole measurement is made to an unprecedented level of precision for radio sources, which is only matched by recent results using infrared quasars.

Jorryt Matthee, Christopher Golling, Ruari Mackenzie, Gabriele Pezzulli, Simon Lilly, Joop Schaye, Roland Bacon, Haruka Kusakabe, Tanya Urrutia, Leindert Boogaard, Jarle Brinchmann, Michael V. Maseda, Thibault Garel, Nicolas F. Bouché, Lutz Wisotzki

Submitted to MNRAS. Main text 9 pages, 9 figures. Key results in Fig 4 (Lya forest transmission in the MXDF field) and Fig 9 (transmission - galaxy distance cross-correlation)

Observationally mapping the relation between galaxies and the intergalactic medium (IGM) is of key interest for studies of cosmic reionization. Diffuse hydrogen gas has typically been observed in HI Lyman-$\alpha$ (Ly$\alpha$) absorption in the spectra of bright background quasars. However, it is important to extend these measurements to background galaxies as quasars become increasingly rare at high redshift and rarely probe closely separated sight-lines. Here we use deep integral field spectroscopy in the MUSE eXtremely Deep Field to demonstrate the measurement of the Ly$\alpha$ transmission at $z\approx4$ in absorption to a background galaxy at $z=4.77$. The HI transmission is consistent with independent quasar sight-lines at similar redshifts. Exploiting the high number of spectroscopic redshifts of faint galaxies (500 between $z=4.0-4.7$ within a radius of 8 arcmin) that are tracers of the density field, we show that Ly$\alpha$ transmission is inversely correlated with galaxy density, i.e. transparent regions in the Ly$\alpha$ forest mark under-dense regions at $z\approx4$. Due to large-scale clustering, galaxies are surrounded by excess HI absorption over the cosmic mean out to 4 cMpc/h. We also find that redshifts from the peak of the Ly$\alpha$ line are typically offset from the systemic redshift by +170 km/s. This work extends results from $z\approx 2 - 3$ to higher redshifts and demonstrates the power of deep integral field spectroscopy to simultaneously measure the ionization structure of the IGM and the large-scale density field in the early Universe.

Donatella Romano, Francesco R. Ferraro, Livia Origlia, Simon Portegies Zwart, Barbara Lanzoni, Chiara Crociati, Davide Massari, Emanuele Dalessandro, Alessio Mucciarelli, R. Michael Rich, Francesco Calura, Francesca Matteucci

14 pages, 2 tables, 8 figures, accepted for publication in ApJ

Terzan 5 is a heavily obscured stellar system located in the inner Galaxy. It has been postulated to be a stellar relic, a Bulge Fossil Fragment witnessing the complex history of the assembly of the Milky Way bulge. In this paper, we follow the chemical enrichment of a set of putative progenitors of Terzan 5 to assess whether the chemical properties of this cluster fit within a formation scenario in which it is the remnant of a primordial building block of the bulge. We can explain the metallicity distribution function and the runs of different element-to-iron abundance ratios as functions of [Fe/H] derived from optical-infrared spectroscopy of giant stars in Terzan 5, by assuming that the cluster experienced two major star formation bursts separated by a long quiescent phase. We further predict that the most metal-rich stars in Terzan 5 are moderately He-enhanced and a large spread of He abundances in the cluster, Y = 0.26-0.335. We conclude that current observations fit within a formation scenario in which Terzan 5 originated from a pristine, or slightly metal-enriched, gas clump about one order of magnitude more massive than its present-day mass. Losses of gas and stars played a major role in shaping Terzan 5 the way we see it now. The iron content of the youngest stellar population is better explained if the white dwarfs that give rise to type Ia supernovae (the main Fe factories) sink towards the cluster center, rather than being stripped by the strong tidal forces exerted by the Milky Way in the outer regions.

William Giarè, Supriya Pan, Eleonora Di Valentino, Weiqiang Yang, Jaume de Haro, Alessandro Melchiorri

12 pages, 1 figure, 2 tables

The cosmic microwave background (CMB) temperature and polarization anisotropies, as observed by independent astronomical missions such as WMAP, Planck, and most recently the Atacama Cosmology Telescope (ACT), have played a vital role in accurately constraining cosmological theories and models, establishing cosmic inflation as the most widely accepted theory for describing the physics of the early Universe. However, the absence of a definitive detection of B-mode polarization and the emerging discrepancies among different CMB experiments present a challenge in determining precise predictions for the inflationary models that best explain the observed data. In this work, we further explore this difficulty and conduct a case study by analyzing four well-known inflationary potentials in light of the most recent CMB observations released by Planck and ACT, along with B-modes polarization data from the BICEP Collaboration, and measurements of Baryon Acoustic Oscillations (BAO) and Redshift Space Distortions (RSD) from BOSS DR12 and eBOSS DR16. We show that the most typical models such as Starobisnky and $\alpha$-attractors are in disagreement with the ACT small-scale CMB measurements, particularly when combined with B-modes polarization data. On the other hand, these potentials are in perfect agreement with the Planck measurements at larger angular scales. This dichotomy makes it challenging to identify a single model or a group of models that can be universally considered as the preferred choice based on all available CMB observations.

Antón Baleato Lizancos, Martin White

25 pages + appendices & bibliography. 13 figures. Code available at this https URL

A leading way to constrain physical theories from cosmological observations is to test their predictions for the angular clustering statistics of matter tracers, a technique that is set to become ever more central with the next generation of large imaging surveys. Interpretation of this clustering requires knowledge of the projection kernel, or the redshift distribution of the sources, and the typical assumption is an isotropic redshift distribution for the objects. However, variations in the the kernel are expected across the survey footprint due to photometric variations and residual observational non-idealities. We develop the formalism for anisotropic projection and present several limiting cases that elucidate the key aspects. We quantify the impact of anisotropies in the redshift distribution on a general class of angular two-point statistics. In particular, we identify a mode-coupling effect that can add power to auto-correlations, including galaxy clustering and cosmic shear, and remove it from certain cross-correlations. If the projection anisotropy is primarily at large scales, the mode-coupling depends upon its variance as a function of redshift; furthermore, it is often of similar shape to the signal. In contrast, the cross-correlation of a field whose selection function is anisotropic with another one featuring no such variations -- such as CMB lensing -- is immune to these effects. We discuss explicitly several special cases of the general formalism including galaxy clustering, galaxy-galaxy lensing, cosmic shear and cross-correlations with CMB lensing, and publicly release a code to compute the biases.

We investigate how our baryon-loss limits from anomalous binary-pulsar period lengthening can be interpreted microscopically to yield specific constraints on the particle physics of baryon number violation within a neutron star. We focus on the possibility of anomalous baryon disappearance via dark baryon processes and on scenarios in which the produced dark-sector particles do not survive to influence the response of the star to baryon-number-violating effects. We flesh out the conditions for which this may occur, as well as other key assumptions. We then turn to the analysis of particle processes in the dense nuclear medium found at the core of a neutron star, employing the techniques of relativistic mean-field theory. Using our study of in-medium effects and limits on macroscopic baryon number violation we extract limits on in-vacuum baryon-number-violating processes, and we determine them for various equations of state. We conclude by noting the implications of our results for models of dark-sector-enabled baryogenesis.

Francesco D'Eramo, Giuseppe Lucente, Newton Nath, Seokhoon Yun

40 pages, 9 figures

Solar nuclear reactions can occasionally produce sub-MeV elusive beyond the Standard Model particles that escape the solar interior without further interactions. This study focuses on massive spin-one particles. We construct the general theoretical framework and identify two crucial mixing sources involving the photon, which facilitate communication between the hidden and visible sectors: kinetic mixing with the photon, and plasma-induced mixing due to thermal electron loops. For both cases, we focus on the second stage of the solar proton-proton chain and evaluate the fluxes of monochromatic 5.49 MeV hidden vectors produced by the $p(d, ^3{\rm He})\gamma^\prime$ nuclear reaction. We then investigate their terrestrial detection via Compton-like scatterings and decays. The incoming fluxes are polarized, and we evaluate the cross sections for Compton-like scatterings for transverse and longitudinal vectors. Finally, we apply this framework to a concrete case by investigating the sensitivity of the forthcoming Jiangmen Underground Neutrino Observatory (JUNO) experiment. We find that JUNO will access an uncharted parameter space region of the kinetic mixing scenario when the vector mass exceeds twice the electron mass.

S. Sandner, P. Hernandez, J. Lopez-Pavon, N. Rius

28 + 4 pages, 8 figures

We consider the generation of a baryon asymmetry in an extension of the Standard Model with two singlet Majorana fermions that are degenerate above the electroweak phase transition. The model can explain neutrino masses as well as the observed matter-antimatter asymmetry, for masses of the heavy singlets below the electroweak scale. The only physical CP violating phases in the model are those in the PMNS mixing matrix, i.e. the Dirac phase and a Majorana phase that enter light neutrino observables. We present an accurate analytic approximation for the baryon asymmetry in terms of CP flavour invariants, and derive the correlations with neutrino observables. We demonstrate that the measurement of CP violation in neutrino oscillations as well as the mixings of the heavy neutral leptons with the electron, muon and tau flavours suffice to pin down the matter-antimatter asymmetry from laboratory measurements.

Marcos A. G. Garcia, Mathias Pierre, Sarunas Verner

6 pages, 3 figures (Supplementary Material: 13 pages, 5 figures)

Conventional scenarios of purely gravitationally produced dark matter with masses below the Hubble parameter at the end of inflation are in tension with Cosmic Microwave Background (CMB) constraints on the isocurvature power spectrum. We explore a more general scenario with a non-minimal coupling between the scalar dark matter field and gravity, which allows for significantly lighter scalar dark matter masses compared to minimal coupling predictions. By imposing relic abundance, isocurvature, Lyman-$\alpha$, and Big Bang Nucleosynthesis (BBN) constraints, we show the viable parameter space for these models. Our findings demonstrate that the presence of a non-minimal coupling expands the parameter space, yielding a dark matter mass lower bound of $2 \times 10^{-4} \, \rm{eV}$.

Francesco Pecora, Sergio Servidio, Yan Yang, William H. Matthaeus, Alexandros Chasapis, Antonella Greco, Daniel J. Gershman, Barbara L. Giles, James L. Burch

A novel multispacecraft technique applied to Magnetospheric Multiscale (MMS) mission data collected in the Earth's magnetosheath enables evaluation of the energy cascade rate solving the full Yaglom's equation in a turbulent space plasma. The method differs from existing approaches in that (i) it is inherently three-dimensional; (ii) it provides a statistically significant number of estimates from a single data stream; and (iii) it allows for a direct visualization of energy flux in turbulent plasmas. This new technique will ultimately provide a realistic, comprehensive picture of the turbulence process in plasmas.

The relativistic hydrodynamics (RHD) equations have three crucial intrinsic physical constraints on the primitive variables: positivity of pressure and density, and subluminal fluid velocity. However, numerical simulations can violate these constraints, leading to nonphysical results or even simulation failure. Designing genuinely physical-constraint-preserving (PCP) schemes is very difficult, as the primitive variables cannot be explicitly reformulated using conservative variables due to relativistic effects. In this paper, we propose three efficient Newton--Raphson (NR) methods for robustly recovering primitive variables from conservative variables. Importantly, we rigorously prove that these NR methods are always convergent and PCP, meaning they preserve the physical constraints throughout the NR iterations. The discovery of these robust NR methods and their PCP convergence analyses are highly nontrivial and technical. As an application, we apply the proposed NR methods to design PCP finite volume Hermite weighted essentially non-oscillatory (HWENO) schemes for solving the RHD equations. Our PCP HWENO schemes incorporate high-order HWENO reconstruction, a PCP limiter, and strong-stability-preserving time discretization. We rigorously prove the PCP property of the fully discrete schemes using convex decomposition techniques. Moreover, we suggest the characteristic decomposition with rescaled eigenvectors and scale-invariant nonlinear weights to enhance the performance of the HWENO schemes in simulating large-scale RHD problems. Several demanding numerical tests are conducted to demonstrate the robustness, accuracy, and high resolution of the proposed PCP HWENO schemes and to validate the efficiency of our NR methods.

This paper proposes and analyzes a novel efficient high-order finite volume method for the ideal magnetohydrodynamics (MHD). As a distinctive feature, the method simultaneously preserves a discretely divergence-free (DDF) constraint on the magnetic field and the positivity-preserving (PP) property, which ensures the positivity of density, pressure, and internal energy. To enforce the DDF condition, we design a new discrete projection approach that projects the reconstructed point values at the cell interface into a DDF space, without using any approximation polynomials. This projection method is highly efficient, easy to implement, and particularly suitable for standard high-order finite volume WENO methods, which typically return only the point values in the reconstruction. Moreover, we also develop a new finite volume framework for constructing provably PP schemes for the ideal MHD system. The framework comprises the discrete projection technique, a suitable approximation to the Godunov--Powell source terms, and a simple PP limiter. We provide rigorous analysis of the PP property of the proposed finite volume method, demonstrating that the DDF condition and the proper approximation to the source terms eliminate the impact of magnetic divergence terms on the PP property. The analysis is challenging due to the internal energy function's nonlinearity and the intricate relationship between the DDF and PP properties. To address these challenges, the recently developed geometric quasilinearization approach is adopted, which transforms a nonlinear constraint into a family of linear constraints. Finally, we validate the effectiveness of the proposed method through several benchmark and demanding numerical examples. The results demonstrate that the proposed method is robust, accurate, and highly effective, confirming the significance of the proposed DDF projection and PP techniques.

Tiberiu Harko

23 pages, 8 figures, accepted for publication in PRD

We consider a generalization of the quintessence type scalar field cosmological models, by adding a multiplicative dissipative term in the scalar field Lagrangian, which is represented in an exponential form. The generalized dissipative Klein-Gordon equation is obtained from the variational principle in a covariant form. The energy-momentum tensor of the dissipative scalar field is also obtained from the dissipative Lagrangian. The generalized Friedmann equations in the presence of the dissipative scalar field are obtained for a specific form of dissipation, with the dissipation exponent represented as the time integral of the product of the Hubble function, and of a function describing the dissipative properties of the scalar field. Several cosmological models, corresponding to different choices of the dissipation function, and of the scalar field potential, are considered in detail. The evolutions of the basic cosmological parameters (Hubble function, deceleration parameter etc.) are investigated by using both analytical and numerical techniques. A comparison with the observational data for the Hubble function, and with the predictions of the standard $\Lambda$CDM paradigm is also presented for each dissipative scalar field model. In the large time limit the model describes an accelerating Universe, with the effective negative pressure induced by the dissipative effects associated to the scalar field. Accelerated expansion in the absence of the scalar field potential is also possible, with the kinetic term dominating the expansionary evolution. The dissipative scalar field models describe well the observational data, with the free parameters of the model obtained by a trial and error method. The obtained results show that the dissipative scalar field model offers an effective dynamical possibility for explaining the recent cosmological observational data.

Einstein-Maxwell dilaton-axion (EMDA) gravity provides a simple framework to investigate the signatures of string theory. The axion and the dilaton fields arising in EMDA gravity have important implications in inflationary cosmology and in addressing the late time acceleration of the universe. It is therefore instructive to explore the implications of such a model in explaining the astrophysical observations. In this work we explore the role of EMDA gravity in explaining the observed shadows of black holes (M87* and Sgr A*) released by the Event Horizon Telescope (EHT) collaboration. The Kerr-Sen metric represents the exact, stationary and axisymmetric black hole solution of EMDA gravity. Such a black hole is characterized by the angular momentum $a$ acquired from the axionic field and the dilatonic charge $r_2$ arising from string compactifications. We study the role of spin and the dilaton charge in modifying the shape and size of the black hole shadow. We note that black holes with larger dilaton charge cast a smaller shadow. We investigate the consequences of such a result in addressing the EHT observations of M87* and Sgr A*. Our analysis reveals that the shadow of M87* exhibits a preference towards the Kerr scenario. However, when 10% offset in the shadow diameter is considered, $0.1\lesssim r_2\lesssim 0.3$ is observationally favored within 1-$\sigma$. The shadow of Sgr A* on the other hand shows a preference towards the Kerr-Sen scenario since the central value of its shadow can be better explained by a non-zero dilaton charge $0.1 \lesssim r_2 \lesssim 0.4$. However, when the 1-$\sigma$ interval is considered the Kerr scenario is included. We discuss the implications of our results.

In a recent work by Fernandes [arXiv:2305.10382], an exact stationary and axisymmetric solution was discovered in semiclassical gravity with type-A trace anomaly, identified as a quantum-corrected version of the Kerr black hole. This discovery presents exciting research opportunities for observing non-circular spacetimes. In this study, we explore the light rings and shadow of this black hole solution. Our investigation reveals that there exist prograde and retrograde normal light rings, whose radii increase monotonically with the coupling parameter $\alpha$. We also observe that when $\alpha$ is negative, the shadow area for the quantum-corrected black hole is smaller than that of the Kerr black hole, whereas when $\alpha$ is positive, the area is larger. Furthermore, the NHEKline for nearly extreme black hole disappears when $\alpha$ is greater than zero, while it appears for negative $\alpha$, even if the spin is not too high. Such line sinks in the middle part when $|\alpha|$ is relatively large if $\alpha$ is less than zero.

The third observing run of advanced LIGO, Virgo and KAGRA brought unprecedented sensitivity towards a variety of quasi-monochromatic, persistent gravitational-wave signals. Continuous waves allow us to probe not just the existence of canonical asymmetrically rotating neutron stars, but also different forms of dark matter, thus showing the wide-ranging astrophysical implications of using a relatively simple signal model. I will describe the major results from the numerous continuous-wave searches that were performed in O3, both inside and outside the LIGO/Virgo/KAGRA collaborations, and show how impactful to multi-messenger physics that they have been.

In the context of $F(\phi)R$ models of gravity, the conformal invariance of the curvature perturbation on the uniform-field slicings has been already demonstrated in several publications. In this work, we study the conformal invariance of the curvature perturbation defined on hypersurfaces that are comoving with an effective fluid. We derive the comoving curvature perturbation in each conformal frame and relate both. It is shown that the conformal invariance of this gauge-invariant curvature perturbation does not always hold, and the analysis on superhorizon and subhorizon scales is performed in the slow-roll regime of inflation. We find that the comoving curvature perturbation is conformally invariant on superhorizon scales but the same cannot be concluded on the subhorizon regime.