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Papers for Friday, Oct 25 2024

Papers with local authors

Amir Siraj, Christopher F. Chyba, Scott Tremaine
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Paper 5 — arXiv:2410.18170
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Paper 5 — arXiv:2410.18170

The plausibility of an unseen planet in the outer solar system, and the expected orbit and mass of such a planet, have long been a topic of inquiry and debate. We calculate the long-term orbital stability of distant trans-Neptunian objects (TNOs), which allows us to expand the sample of objects that would carry dynamical information about a hypothetical unseen planet in the outer solar system. Using this expanded sample, we find statistically significant clustering at the 3σ level for TNOs with semimajor axes >170\;AU, in longitude of perihelion (ϖ), but not in inclination (i), argument of perihelion (ω) or longitude of node (Ω). Since a natural explanation for clustering in ϖ is an unseen planet, we run 300 n-body simulations with the giant planets, a disk of test particles representing Kuiper belt objects, and an additional planet with varied initial conditions for its mass, semimajor axis, eccentricity, and inclination. Based on the distribution of test particles after 1--2 Gyr, we compute relative likelihoods given the actual distribution of ϖ as a function of semimajor axis for distant TNOs on stable orbits using a significantly larger sample (N=51) than previous work (N=11). We find that the unseen planet parameters that best fit the data are a mass of mp=4.4±1.1M, a semimajor axis of ap=290±30AU, an eccentricity of ep=0.29±0.13, and an inclination of ip=6.8±5.0 (all error bars are 1σ). Only 0.06% of the Brown & Batygin (2021) reference population produce probabilities within 1σ of the maximum within our quadrivariate model, indicating that our work identifies a distinct preferred region of parameter space for an unseen planet in the solar system. If such an unseen planet exists, it is likely to be discovered by LSST.

All other papers

Carlos Navia, Marcel Oliveira, B. Felicio, Andre Nepomuceno

We analyze a bright and rare burst, GRB20221009A, showing through NED data that the angular distance between GRB221009A and the supernova SN 2022xiw is almost the same angular separation with galactic objects, i.e., the SN-GRB connection at z = 0.151 is not robust. Gamma rays with up to 18 TeV detected in association with the GRB constrain the attenuation to which they are subject at cosmological distances. GR221009A is out of scale relative to other long-lasting GRBs and comes from a region with an excess of soft gamma repeaters (SGR), suggesting that GRB221009A is a giant SGR, with energy release Eiso aproximately 10^{44} erg. The GRBs propagation across the galactic plane reinforces this assumption.

Takuro Fujino, Satoru Takakura, Shahed Shayan Arani, Darcy Barron, Carlo Baccigalupi, Yuji Chinone, Josquin Errard, Giulio Fabbian, Chang Feng, Nils W. Halverson, Masaya Hasegawa, Masashi Hazumi, Oliver Jeong, Daisuke Kaneko, Brian Keating, Akito Kusaka, Adrian Lee, Tomotake Matsumura, Lucio Piccirillo, Christian L. Reichardt, Kana Sakaguri, Praween Siritanasak, Kyohei Yamada

At millimeter wavelengths, the atmospheric emission is circularly polarized owing to the Zeeman splitting of molecular oxygen by the Earth's magnetic field. We report a measurement of the signal in the 150 GHz band using 3 years of observations of the \textsc{Polarbear} project. Although the detectors are sensitive to linear polarization, we can measure the circular polarization because a continuously rotating half-wave plate in the optics converts part of circular polarization into linear polarization. The atmospheric circular polarization signal appears as a modulated signal at twice the frequency of rotation of the half-wave plate. We reconstruct the azimuthal gradient of the circular polarization signal and measure the dependencies on the scanning azimuth and the detector bandpass. We compare the signal with a simulation based on atmospheric emission theory, the detector bandpass, and the half-wave plate leakage spectrum model. We find the ratio of the observed azimuthal slope to the simulated slope is 0.92±0.01(stat)±0.07(sys), which demonstrates that our measurement is consistent with theoretical prediction. This result validates our understanding of the instrument and reinforces the feasibility of measuring the circular polarization using the imperfection of the half-wave plate. Quantifying atmospheric circular polarization is the first step toward conducting a search for cosmological circular polarization at these wavelengths.

Mauro Sereno, Sophie Maurogordato, Alberto Cappi, Rafael Barrena, Christophe Benoist, Christopher P. Haines, Mario Radovich, Mario Nonino, Stefano Ettori, Antonio Ferragamo, Raphael Gavazzi, Sophie Huot, Lorenzo Pizzuti, Gabriel W. Pratt, Alina Streblyanska, Stefano Zarattini, Gianluca Castignani, Dominique Eckert, Fabio Gastaldello, Scott T. Kay, Lorenzo Lovisari, Ben J. Maughan, Etienne Pointecouteau, Elena Rasia, Mariachiara Rossetti, Jack Sayers

The Cluster HEritage project with XMM-Newton - Mass Assembly and Thermodynamics at the Endpoint of structure formation (CHEX-MATE) is a programme to study a minimally biased sample of 118 galaxy clusters detected by Planck through the Sunyaev-Zeldovich effect. Accurate and precise mass measurements are required to exploit CHEX-MATE as an astrophysical laboratory and a calibration sample for cosmological probes in the era of large surveys. We measured masses based on the galaxy dynamics, which are highly complementary to weak-lensing or X-ray estimates. We analysed the sample with a uniform pipeline that is stable both for poorly sampled or rich clusters - using spectroscopic redshifts from public (NED, SDSS, and DESI) or private archives - and dedicated observational programmes. We modelled the halo mass density and the anisotropy profile. Membership is confirmed with a cleaning procedure in phase space. We derived masses from measured velocity dispersions under the assumed model. We measured dynamical masses for 101 CHEX-MATE clusters with at least ten confirmed members within the virial radius r_200c. Estimated redshifts and velocity dispersions agree with literature values when available. Validation with weak-lensing masses shows agreement within 8+-16(stat.)+-5(sys.)%, and confirms dynamical masses as an unbiased proxy. Comparison with {\it Planck} masses shows them to be biased low by 34+-3(stat.)+-5(sys.)%. A follow-up spectroscopic campaign is underway to cover the full CHEX-MATE sample.

G. Piotto, T. Zingales, L. Borsato, J. A. Egger, A. C. M. Correia, A. E. Simon, H.-G. Florén, S. G. Sousa, P. F. L. Maxted, T. G. Wilson, Y. Alibert, V. Adibekyan, A. Bonfanti, R. Luque, N. C. Santos, M. J. Hooton, L. Fossati, L. M. Serrano, A. M. S. Smith, S. Salmon, G. Lacedelli, R. Alonso, T. Bárczy, D. Barrado Navascues, S. C. C. Barros, W. Baumjohann, T. Beck, W. Benz, N. Billot, A. Brandeker, C. Broeg, A. Collier Cameron, Sz. Csizmadia, P. E. Cubillos, M. B. Davies, M. Deleuil, A. Deline, O. D. S. Demangeon, B.-O. Demory, A. Derekas, B. Edwards, D. Ehrenreich, A. Erikson, A. Fortier, M. Fridlund, D. Gandolfi, K. Gazeas, M. Gillon, M. Güdel, M. N. Günther, A. Heitzmann, Ch. Helling, K. G. Isaak, L. L. Kiss, J. Korth, K. W. F. Lam, J. Laskar, A. Lecavelier des Etangs, M. Lendl, P. Leonardi, D. Magrin, C. Mordasini, V. Nascimbeni, G. Olofsson, R. Ottensamer, I. Pagano, E. Pallé, G. Peter, D. Pollacco, D. Queloz, R. Ragazzoni, N. Rando, H. Rauer, I. Ribas, G. Scandariato, D. Ségransan, M. Stalport, S. Sulis, Gy. M. Szabó, S. Udry, S. Ulmer-Moll, V. Van Grootel, J. Venturini, E. Villaver, N. A. Walton

We present new observations from CHEOPS and TESS to clarify the architecture of the planetary system hosted by the old Galactic thick disk star TOI-561. Our global analysis, which also includes previously published photometric and radial velocity data, incontrovertibly proves that TOI-561 is hosting at least four transiting planets with periods of 0.44 days (TOI-561 b), 10.8 days (TOI-561 c), 25.7 days (TOI-561 d), and 77.1 days (TOI-561 e) and a fifth non-transiting candidate, TOI-561f with a period of 433 days. The precise characterisation of TOI-561's orbital architecture is interesting since old and metal-poor thick disk stars are less likely to host ultra-short period Super-Earths like TOI-561 b. The new period of planet -e is consistent with the value obtained using radial velocity alone and is now known to be 77.14399±0.00025 days, thanks to the new CHEOPS and TESS transits. The new data allowed us to improve its radius (Rp=2.517±0.045R from 5% to 2% precision) and mass (Mp=12.4±1.4M) estimates, implying a density of ρp=0.778±0.097ρ. Thanks to recent TESS observations and the focused CHEOPS visit of the transit of TOI-561 e, a good candidate for exomoon searches, the planet's period is finally constrained, allowing us to predict transit times through 2030 with 20-minute accuracy. We present an updated version of the internal structure of the four transiting planets. We finally performed a detailed stability analysis, which confirmed the long-term stability of the outer planet TOI-561 f.

Stellar-mass black-hole binaries are the most numerous gravitational-wave sources observed to date. Their properties make them suitable for observation both by ground- and space-based detectors. Starting from synthetic catalogues constructed based on observational constraints from ground-based detectors, we explore the detection rates and the characteristic parameters of the stellar-mass black-hole binaries observable by LISA during their inspiral, using signal-to-noise ratio thresholds as a detection criterion. We find that only a handful of these sources will be detectable with signal-to-noise ratio larger than 8: about 5 sources on average in 4 years of mission duration, among which only one or two are multiband ones (i.e. merging in less than 15 years). We find that detectable sources have chirp mass 10M, residual time-to-coalescence 4\mathrm{yr}\lesssim \tau_c\lesssim 100 \mathrm{yr}, and redshift z\lesssim 0.1, much closer than those observed up to now by ground-based detectors. We also explore correlations between the number of LISA detectable sources and the parameters of the population, suggesting that a joint measurement with the stochastic signal might be informative of the population characteristics. By performing parameter estimation on a subset of sources from the catalogues, we conclude that, even if LISA measurements will not be directly informative on the population due to the low number of resolvable sources, it will characterise a few, low-redshift candidates with great precision. Furthermore, we construct for the first time the LISA waterfall plot for low chirp mass, and demonstrate that LISA will also be able to discriminate and characterize, through very precise parameter estimation, a population of binaries with higher masses, \mathcal{M}_c\sim \mathcal{O}(10^3) M_\odot, if it exists.

Irene Ferranti, Mikel Falxa, Alberto Sesana, Aurelien Chalumeau, Nataliya Porayko, Golam Shaifullah, Ismael Cognard, Lucas Guillemot, Michael Kramer, Kuo Liu, Gilles Theureau

Pulsar Timing Array (PTA) collaborations gather high-precision timing measurements of pulsars with the aim of detecting gravitational wave (GW) signals. A major challenge lies in the identification and characterization of the different sources of noise that may hamper their sensitivity to GWs. The presence of time-correlated noise that resembles the target signal might give rise to degeneracies that can directly impact the detection statistics. In this work, we focus on the covariance that exists between a "chromatic" dispersion measure (DM) noise and an "achromatic" stochastic gravitational wave background (GWB). "Chromatic" associated to the DM noise means that its amplitude depends on the frequency of the incoming pulsar photons measured by the radio-telescope. Several frequency channels are then required to accurately characterise its chromatic features and when the coverage of incoming frequency is poor, it becomes impossible to disentangle chromatic and achromatic noise contributions. In this paper, we explore this situation by injecting realistic GWB into 100 realizations of two mock versions of the second data release (DR2) of the European PTA (EPTA), characterized by different frequency coverage. The first dataset is a faithful copy of DR2, in which the first half of the data is dominated by only one frequency channel of observation; the second one is identical except for a more homogeneous frequency coverage across the full dataset. We show that for 91% of the injections, a better frequency coverage leads to an improved statistical significance (~1.3dex higher log Bayes factor on average) of the GWB and a better characterization of its properties. We propose a metric to quantify the degeneracy between DM and GWB parameters and show that it is correlated with a loss of significance for the recovered GWB and an increase in the GWB bias towards a higher and flatter spectral shape.

We provide an updated inference of the proper motion of M31 using the Gaia DR3 proper motions of bright stars from the disc of M31. By refining the motion of the quasar reference frame, and statistically accounting for the variations in the inferred proper motions obtained across different regions of M31, we demonstrate that these inconsistencies most likely arise from systematic uncertainties. Our updated favoured values for the proper motion of M31 are 46.9\pm11.7(stat)\pm50.6(sys)\muas yr^{-1} along the right ascension direction, and -29.1\pm9.4(stat)\pm35.6(sys)\muas yr^{-1} along the declination direction, the systematics being determined at a 90% confidence level (the values for M33 are given in the paper). This clearly highlights that the systematics are the dominant source of uncertainty, their magnitudes being comparable to the proper motion of M31 itself. The analysis conducted using Gaia DR2 instead of DR3 revealed that a net reduction in these systematic uncertainties occurred between the two data releases. If similar progress is made with the upcoming DR4, the future Gaia-based estimates could match the level of uncertainties of HST, and could be used to refine the dynamics and history of M31 and M33.

Spectroscopic observations of exoplanet atmospheres can reveal the chemical composition, temperature, cloud properties, and (potentially) the habitability of these distant worlds. The inference of such properties is generally enabled by Bayesian atmospheric retrieval algorithms. However, until recently, many retrieval codes have not been publicly available. Here, we describe the open source release of the POSEIDON exoplanet radiative transfer and retrieval code. POSEIDON is a Python package for the 1D, 2D, or 3D modelling and analysis of exoplanet spectra, which is frequently used to interpret Hubble and JWST observations of exoplanet atmospheres. We provide extensive tutorials on both forward modelling and retrievals in POSEIDON's online documentation, which we hope will serve as a helpful resource for the exoplanet atmosphere community.

Himansh Rathore (U. Arizona), Yumi Choi (NSF NOIRLab), Knut A.G. Olsen (NSF NOIRLab), Gurtina Besla (U. Arizona)

We present new measurements of the two-dimensional (2-D) geometry of the LMC's stellar bar with precise astrometric observations of red clump stars in Gaia DR3. We develop a novel solution to tackle crowding induced incompleteness in Gaia datasets with the Gaia BP-RP color excess. Utilizing the color excess information, we derive a 2-D completeness map of the LMC's disk. We find that incompleteness biases the bar measurements and induces large uncertainties. With the completeness-corrected 2-D red clump map, we precisely measure the LMC bar's properties for the first time using Fourier decomposition. The bar radius is R_{bar} = 2.13^{+0.03}_{-0.04} kpc, and its position angle is 121.26^{\circ} \pm 0.21^{\circ}. The bar's strength as quantified by the Fourier bi-symmetric amplitude is S_{bar} = 0.27, indicating that the LMC has a significant bar perturbation. We find the bar has an axis ratio of 0.54 \pm 0.03, and is offset with respect to the center of the outer disk isophote at R \approx 5 kpc by 0.76 \pm 0.01 kpc. These LMC bar properties agree with a hydrodynamic model where the SMC has undergone a recent direct collision with the LMC. We compare the LMC's bar properties with other barred galaxies in the local universe, and discover that the LMC is similar to other barred galaxies in terms of bar-galaxy scaling relations. We discuss how our completeness correction framework can be applied to other systems in the Local Group.

Stefan Pelletier, Björn Benneke, Yayaati Chachan, Luc Bazinet, Romain Allart, H. Jens Hoeijmakers, Alexis Lavail, Bibiana Prinoth, Louis-Philippe Coulombe, Joshua D. Lothringer, Vivien Parmentier, Peter Smith, Nicholas Borsato, Brian Thorsbro

One of the outstanding goals of the planetary science community is to measure the present-day atmospheric composition of planets and link this back to formation. As giant planets are formed by accreting gas, ices, and rocks, constraining the relative amounts of these components is critical to understand their formation and evolution. For most known planets, including the Solar System giants, this is difficult as they reside in a temperature regime where only volatile elements (e.g., C, O) can be measured, while refractories (e.g., Fe, Ni) are condensed to deep layers of the atmosphere where they cannot be remotely probed. With temperatures allowing for even rock-forming elements to be in the gas phase, ultra-hot Jupiter atmospheres provide a unique opportunity to simultaneously probe the volatile and refractory content of giant planets. Here we directly measure and obtain bounded constraints on the abundances of volatile C and O as well as refractory Fe and Ni on the ultra-hot giant exoplanet WASP-121b. We find that ice-forming elements are comparatively enriched relative to rock-forming elements, potentially indicating that WASP-121b formed in a volatile-rich environment much farther away from the star than where it is currently located. The simultaneous constraint of ice and rock elements in the atmosphere of WASP-121b provides insights into the composition of giant planets otherwise unattainable from Solar System observations.

S. Britzen, A.B. Kovačević, M. Zajaček, L. Č. Popović, I.N. Pashchenko, E. Kun, R. Pánis, F. Jaron, T. Plšek, A. Tursunov, Z. Stuchlík

The BL Lac Object PKS 1717+177 has been identified as potential neutrino-emitting AGN in the point source stacking analysis of IceCube data. We explore peculiarities in the morphology and kinematics of the jet and examine multi-wavelength light curves for distinctive effects which might allow to pinpoint a likely neutrino generation mechanism. We re-modeled 34 high resolution radio interferometric Very Long Baseline Array (VLBA) observations obtained at 15 GHz (between 1999/12/27 and 2023/05/03). A correlation and periodicity analysis of optical KAIT and Tuorla data, as well as for Fermi-LAT \gamma-ray data has been performed. The nuclear jet appears deflected and bent at about 0.5 mas distance from the radio core by an encounter with a dark, unseen object. The deviation of the jet evolves over 23.5 years from a simple apparent bend into a significantly meandering structure with increasing amplitude: a zig-zag line. To our knowledge, this is the first time that the temporal evolution of a jet deviation can be traced. The turning point shifts with time and the jet seems to brighten up almost periodically at the point of deviation. The radio core as well as the jet contribute approximately equally to the total flux-density at 15 GHz. We discuss scenarios which could explain the complex jet bending and quasi-regular flaring. We propose that the jet could either be deflected by the magnetosphere of a second massive black hole, by the pressure gradient due to a circumnuclear dense cloud, or via gravitational lensing by an intervening black hole.

We analyse synthetic maps of the [CII] 158 \mum line and FIR continuum of simulated molecular clouds (MCs) within the SILCC-Zoom project to study the origin of the [CII]-deficit, i.e., the drop of the [CII]/FIR intensity ratio. All simulations include stellar radiative feedback and account for further ionisation of C^+ into C^{2+} inside HII regions. For individual HII regions, I_\mathrm{FIR} is initially high in the vicinity of young stars, and then moderately decreases as the gas is compressed into shells. In contrast, I_\mathrm{CII} drops strongly over time, to which the second ionisation of C^+ into C^{2+} contributes. This leads to a strong drop of I_\mathrm{[CII]}/I_\mathrm{FIR} inside HII regions, decreasing from 10^{-3}-10^{-2} at scales above 10 pc to 10^{-6}-10^{-4} at scales below 2pc. However, projection effects can affect the radial profile of I_\mathrm{[CII]} and I_\mathrm{FIR} and create apparent HII regions without any stars. On MC scales, L_\mathrm{[CII]}/L_\mathrm{FIR} decreases from values \gtrsim10^{-2} in MCs without star formation to values around \sim10^{-3} in MCs with star formation. We attribute this and the origin of the [CII]-deficit to two main contributors: (i) the saturation of the [CII] line and (ii) the conversion of C^+ into C^{2+} by stellar radiation. The drop of L_\mathrm{[CII]}/L_\mathrm{FIR} can be divided into two phases: (i) early on, the saturation of [CII] and the further ionisation of C^+ limit the increase of L_\mathrm{[CII]}, while L_\mathrm{FIR} increases rapidly, leading to the initial decline of L_\mathrm{[CII]}/L_\mathrm{FIR}. (ii) In more evolved HII regions, L_\mathrm{CII} stagnates and partially even drops due to the aforementioned reasons. L_\mathrm{FIR} stagnates as the gas gets pushed into the cooler shells keeping L_\mathrm{[CII]}/L_\mathrm{FIR} at low values of \sim10^{-3}.

Maria Jose Colmenares, Edwin Bergin, Colette Salyk, Klaus M. Pontopiddan, Nicole Arulanantham, Jenny Calahan, Andrea Banzatti, Sean Andrews, Geoffrey A. Blake, Fred Ciesla, Joel Green, Feng Long, Michiel Lambrechts, Joan Najita, Ilaria Pascucci, Paola Pinilla, Sebastiaan Krijt, Leon Trapman, the JDISCS Collaboration

It has been proposed, and confirmed by multiple observations, that disks around low mass stars display a molecule-rich emission and carbon-rich disk chemistry as compared to their hotter, more massive solar counterparts. In this work, we present JWST Disk Infrared Spectral Chemistry Survey (JDISCS) MIRI-MRS observations of the solar-mass star DoAr 33, a low-accretion rate T Tauri star showing an exceptional carbon-rich inner disk. We report detections of H_2O, OH, and CO_2, as well as the more complex hydrocarbons, C_2H_2 and C_4H_2. Through the use of thermochemical models, we explore different spatial distributions of carbon and oxygen across the inner disk and compare the column densities and temperatures obtained from LTE slab model retrievals. We find a best match to the observed column densities with models that have carbon enrichment, and the retrieved emitting temperature and area of C_2H_2 with models that have C/O = 2-4 inside the 500 K carbon-rich dust sublimation line. This suggests that the origin of the carbon-rich chemistry is likely due to the sublimation of carbon rich grains near the soot line. This would be consistent with the presence of dust processing as indicated by the detection of crystalline silicates. We propose that this long-lived hydrocarbon rich chemistry observed around a solar-mass star is a consequence of the unusually low M-star-like accretion rate of the central star, which lengthens the radial mixing timescale of the inner disk allowing the chemistry powered by carbon grain destruction to linger.

NGC 2506 is a rich, intermediate-age (2.0 Gyr), metal-poor ([Fe/H] \sim -0.2) open cluster. This work presents the results of 12,157 spectroscopic radial-velocity measurements of 2,442 stars in the NGC 2506 field over 41 years, made as part of the WIYN Open Cluster Study. Radial-velocity measurements are complete for the population of proper-motion member stars brighter than a Gaia G magnitude of 15.5, in which 320 proper-motion and radial-velocity cluster members were identified. Within the observation limit of G < 16.5, 469 proper-motion and radial-velocity members were identified. This work reports on the characteristics of NGC 2506, including projected spatial distribution, radial-velocity dispersion, and virial mass. This work also presents orbital solutions for 49 binary members with periods between 1 and 7,580 days. NGC 2506 has an incompleteness-corrected binary frequency for binaries with periods less than 10^4 days of 35 \pm 5%. This work also discusses in detail the 14 blue stragglers stars of NGC 2506\unicode{x2014}finding at least 64 \pm 21% to be in binaries, 5 yellow straggler stars, and several other stars of note.

Zhibo Yu, W. N. Brandt, Fan Zou, Ziyuan Zhu, Franz E. Bauer, Nathan Cristello, Bin Luo, Qingling Ni, Fabio Vito, Yongquan Xue

Dust-obscured galaxies (DOGs) are enshrouded by dust, and many are believed to host accreting supermassive black holes (SMBHs), which makes them unique objects for probing the coevolution of galaxies and SMBHs. We select and characterize DOGs in the 13\,deg^2 XMM-Spitzer Extragalactic Representative Volume Survey (XMM-SERVS), leveraging the superb multiwavelength data from X-rays to radio. We select 3738 DOGs at z\approx1.6-2.1 in XMM-SERVS, while maintaining good data quality without introducing significant bias. This represents the largest DOG sample with thorough multiwavelength source characterization. Spectral energy distribution (SED) modeling shows DOGs are a heterogeneous population consisting of both normal galaxies and active galactic nuclei (AGNs). Our DOGs are massive (\log M_\bigstar/M_\odot\approx10.7-11.3), 174 are detected in X-rays, and they are generally radio-quiet systems. X-ray detected DOGs are luminous and are moderately to heavily obscured in X-rays. Stacking analyses for the X-ray undetected DOGs show highly significant average detections. Critically, we compare DOGs with matched galaxy populations. DOGs have similar AGN fractions compared with typical galaxy populations. X-ray detected DOGs have higher M_\bigstar and higher X-ray obscuration, but they are not more star-forming than typical X-ray AGNs. The results potentially challenge the relevance of the merger-driven galaxy-SMBH coevolution framework for X-ray detected DOGs.

Ottavia Truttero, Joe Zuntz, Alkistis Pourtsidou, Naomi Robertson

Accurately modelling matter power spectrum effects at small scales, such as baryonic feedback, is essential to avoid significant bias in the estimation of cosmological parameters with cosmic shear. However, Stage IV surveys like LSST will be so precise that significant information can still be extracted from large scales alone. In this work, we simulate LSST Y1-like mock data and perform a cosmic shear analysis, considering different models of baryonic feedback. To focus on large scales, we apply physically motivated scale cuts which account for the redshift dependence of the multipoles in the tomographic bin. Our main focus is to study the changes in the constraining power of S_8 and \Omega_m parameters and assess possible effects on the tension with Planck measurements. We find that the S_8 tension is clearly detectable at k_{\rm eff}^{\rm max}=0.20\,h\rm Mpc^{-1} in the analysis where we imposed a DES-sized tension, and at k_{\rm eff}^{\rm max}=0.10\,h\rm Mpc^{-1} with a KiDS-sized tension, regardless of whether an incorrect model for baryons is assumed. However, to achieve these results, LSST will need high precision measurement of the redshift distributions, with photo-z biases of the order of 10^{-3}. Without this, the ability to constrain cosmological parameters independently of baryonic feedback - particularly regarding the S_8 tension - will be compromised.

M. S. Silcock, E. Curtis-Lake, D. J. B. Smith, I. E. B. Wallace, A. Vidal-García, A. Plat, M. Hirschmann, A. Feltre, J. Chevallard, S. Charlot, S. Carniani, A. J. Bunker

The presence of Active Galactic Nuclei (AGN) in low mass (Mstar \lesssim 10^{9} Msun) galaxies at high redshift has been established, and it is important to characterise these objects and the impact of their feedback on the host galaxies. In this paper we apply the Spectral Energy Distribution (SED) fitting code BEAGLE-AGN to SMACS S06355, a z \sim 7.66 Type-II AGN candidate from the JWST NIRSpec Early Release Observations. This object's spectrum includes a detection of the [NeIV]2426 line, indicating an obscured AGN due to its high ionization potential energy (\sim 63eV). We use BEAGLE-AGN to simultaneously model the Narrow Line Region (NLR) AGN and star-forming galaxy contributions to the observed line fluxes and photometry. Having a high-ionization emission line allows the contribution of the NLR to the remaining lines to be probabilistically disentangled. The HII region metallicity is derived to be 12+log(O/H)^{\mathrm{HII}} = 7.74^{+0.18}_{-0.19}. Assuming that the Neon-to-Oxygen abundance is similar to solar we derive a high NLR metallicity of 12+log(O/H)^\mathrm{NLR} = 8.77^{+0.14}_{-0.16}, with the 2\sigma lower-limit extending to 12+log(O/H)^{\mathrm{NLR}} \sim 8.00, showing the derivation is uncertain. We discuss this result with respect to non-solar Neon abundances that might boost the inferred NLR metallicity. The NLR metallicity places SMACS S06355 in a comparable region of the mass-metallicity plane to intermediate (1.5 \lesssim z \lesssim 3.0) redshift obscured AGN. Our derived accretion disc luminosity, log(L_{acc} / erg s^{-1}) = 45.19^{+0.12}_{-0.11}, is moderately high yet still uncertain. We highlight that deviations between bolometric luminosity calibrations and model grid tracks become enhanced at low metallicities.

Marco Turchetta, Manuel Linares, Karri Koljonen, Jorge Casares, Paulo A. Miles-Páez, Pablo Rodríguez-Gil, Tariq Shahbaz, Jordan A. Simpson

We report here the results obtained from a systematic optical photometric survey aimed at finding new compact binary millisecond pulsars (also known as "spiders"): the COmpact BInary PULsar SEarch (COBIPULSE). We acquired multi-band optical images over one year around 33 unidentified Fermi-LAT sources, selected as pulsar candidates based on their curved GeV spectra and steady \gamma-ray emission. We present the discovery of four optical variables coinciding with the Fermi sources 3FGL J0737.2-3233, 3FGL J2117.6+3725 (two systems in this field) and 3FGL J2221.6+6507, which we propose as new candidate spider systems. Indeed, they all show optical flux modulation consistent with orbital periods of 0.3548(5) \ \mathrm{d}, 0.25328(6) \ \mathrm{d}, 0.441961(2) \ \mathrm{d}, and 0.165(4) \ \mathrm{d}, respectively, with amplitudes \gtrsim 0.3 \ \mathrm{mag} and colors compatible with companion star temperatures of 5000--6000 \ \mathrm{K}. These properties are consistent with the "redback" sub-class of spider pulsars. If confirmed as a millisecond pulsar, 3FGL J0737.2-3233 will be the closest known spider to Earth (D=659_{-20}^{+16} \ \mathrm{pc}, from Gaia-DR3 parallax). We searched and did not find any X-ray sources matching our four candidates, placing 3\sigma upper limits of \sim10^{31}--10^{32} \ \mathrm{erg} \ \mathrm{s}^{-1} (0.3--10 \ \mathrm{keV}) on their soft X-ray luminosities. We also present and discuss other multi-wavelength information on our spider candidates, from infrared to X-rays.

Two formulations of superfluidity are reviewed: Landau's phenomenological two-fluid model and a relativistic effective field theory description. We demonstrate how the two-fluid formalism can be recovered from the nonrelativistic limit of the relativistic effective theory at finite temperatures. We show how self-gravitating, nonrelativistic superfluids are obtained from the Newtonian limit of the relativistic approach on curved spaces. The concepts are presented in an accessible manner for readers who may not be deeply familiar with superfluidity from a condensed matter perspective.

During the solar cycle, the Sun's magnetic field polarity reverses due to the emergence, cancellation, and advection of magnetic flux towards the rotational poles. Flux emergence events occasionally cluster together, although it is unclear if this is due to the underlying solar dynamo or simply by chance. Regardless of the cause, we aim to characterise how the reversal of the Sun's magnetic field and the structure of the solar corona are influenced by nested flux emergence. From the spherical harmonic decomposition of the Sun's photospheric magnetic field, we identify times when the reversal of the dipole component stalls for several solar rotations. Using observations from sunspot cycle 23 to present, we locate the nested active regions responsible for each stalling and explore their impact on the coronal magnetic field using potential field source surface extrapolations. Nested flux emergence has a more significant impact on the topology of the coronal magnetic field than isolated emergences as it produces a coherent (low spherical harmonic order) contribution to the photospheric magnetic field. The heliospheric current sheet (HCS), that separates oppositely directed coronal magnetic field, can become anchored above these regions due to the formation of strong opposing magnetic fluxes. Further flux emergence, cancellation, differential rotation, and diffusion, then effectively advects the HCS and shifts the dipole axis. Nested flux emergence can restrict the evolution of the HCS and impede the reversal of the coronal magnetic field. The sources of the solar wind can be more consistently identified around nested active regions as the magnetic field topology remains self-similar for multiple solar rotations. This highlights the importance of identifying nested active regions to guide the remote-sensing observations of modern heliophysics missions.

A. E. Lynas-Gray (1, 2, 3), O. L. Polyansky (1, 4), J. Tennyson (1), S. N. Yurchenko (1), N. F. Zobov (4) ((1) Department of Physics and Astronomy, University College London, London, UK, (2) Department of Physics, University of Oxford, UK, (3) Department of Physics and Astronomy, University of the Western Cape, Bellville, South Africa, (4) Institute of Applied Physics, Russian Academy of Science, Nizhnii Novgorod, Russia)

Improved opacities are needed for modelling the atmospheres and evolution of cool carbon-rich stars and extra-solar planets; in particular, contributions made by the astrophysically important propadienediylidene (C_3) molecule need, at a minimum, to be determined using a line list which includes all significant transitions in the energy range of interest. We report variational calculations giving ro-vibrational energy levels and corresponding line-strengths for ^{12}C_3, ^{12}C^{13}C^{12}C and ^{12}C^{12}C^{13}C. In the ^{12}C_3 case we obtain 2166503 ro-vibrational state energies \le 20000 cm^{-1} for the electronic \tilde{X}^1 \Sigma_g^+ ground-state. Comparison with experiment indicates a maximum error of +/- 0.03 cm^{-1} in calculated positions of lines involving an upper state energy \lesssim 4000 cm^{-1}. For lines with upper state energies \gtrsim 4000 cm^{-1} to have comparable line-position accuracies, conical intersections would need to be accounted for in an adopted potential energy surface. Line lists and associated opacities are provided in the ExoMol Database this http URL ).

The detection of gravitational waves (GWs) has provided a new tool to study the Universe, with the scientific return enriched when combined with established probes: electromagnetic (EM) radiation and energetic particles. Since the groundbreaking detection in 2017 of merging neutron stars producing GW emission, a gamma-ray burst and an optical 'kilonova', the field has grown rapidly. At present, no additional neutron star mergers have been jointly detected in GW and EM radiation, but with upgrades in EM and GW facilities now is a chance to take stock of almost a decade of observations. We discuss the motivations for following up GW sources and the basic challenges of searching large areas for a rapidly-evolving EM signal. We examine how the kilonova counterpart to GW170817 was discovered and the association confirmed, and outline some of the key physics enabled by this discovery. We then review the status of EM searches since 2017, highlighting areas where more information (in GW alerts or catalogs) can improve efficiency, and discuss what we have learned about kilonovae despite the lack of further multi-messenger detections. We discuss upcoming facilities and the many lessons learned, considering also how these could inform searches for lensed mergers.

Stefano Marchesi, Antonio Iuliano, Elisa Prandini, Paolo Da Vela, Michele Doro, Serena Loporchio, Davide Miceli, Chiara Righi, Roberta Zanin, Ettore Bronzini, Cristian Vignali

We present the results of a multi-wavelength study of blazars selected from the 5th ROMABZCAT catalog. We selected from this sample a subsample of 2435 objects having at least one counterpart in one of the three main archival X-ray catalogs, which is, the fourth release of the XMM-Newton Survey Science Catalogue, the second release of the Chandra Source Catalog, and the second Swift X-ray Point Source catalog of detections by Swift-XRT, or in the recently released eROSITA-DE Data Release 1 catalog. We first searched for different multi-wavelength trends between sources with a Gamma-ray counterpart in the Fermi-LAT 14-year Source Catalog (4FGL-DR4) and sources lacking one. We find that the non-4FGL sources are on average fainter both in the X-rays and in the radio with respect to the 4FGL-detected ones, but the two samples have similar X-ray-to-radio flux ratios, as well as synchrotron peak frequencies. We then focused on the 1007 non-Gamma-ray detected population, to determine if there is a sample of X-ray sources that could be TeV emitters. We find that a large number of sources, mostly BL Lacs or BL Lacs with host-galaxy contribution to the spectral energy distribution, have large synchrotron peak frequency and X-ray to radio flux ratio, two properties that characterize the vast majority of known TeV emitters. With respect to these known TeV emitters, our targets have X-ray fluxes ~1 order of magnitude fainter. We then computed the 0.2-12 keV and 20 GeV - 300 TeV fluxes for the known 5BZCAT TeV emitters, and determined the existence of a direct correlation between X-ray and TeV fluxes in the BL Lacs population. We used this trend to estimate the VHE flux of our targets, and found a promising sample of sources for follow-up observations with current or future, more sensitive, Cherenkov telescopes, first and foremost the Cherenkov Telescope Array Observatory.

Eka Puspita Arumaningtyas, Hasan Al Rasyid, Maria Giovanna Dainotti, Daisuke Yonetoku

The X-ray column density (NHX) of gamma-ray bursts (GRBs) can probe the local environment of their progenitors over a wide redshift range. Previous work has suggested an increasing trend as a function of redshift. The relevance of the current analysis relies on investigating the selection bias method, such as the effect of the X-ray spectrum in high-redshift GRBs, which complicates the measurement of small NHX, have yet to be fully evaluated or discussed elsewhere. In this work, we evaluated these effects through simulations to define appropriate observational limits in the NHX versus redshift plane. We then applied a one-sided nonparametric method developed by Efron and Petrosian. Within the framework of this method, we investigated the redshift dependence of NHX and the local distribution function. Our results show that the evolution of NHX with redshift firmly exists with a significance of more than four sigma and follows a power law of (1+z)^{1.39 (+0.22, -0.27)}. Based on these analyses and previous studies, the GRB progenitor mass varies but is more massive in the high redshift environment and has a higher gas column density. This suggests that part of the luminosity evolution of GRBs, which has been widely reported, may be due to the evolution of the progenitor's mass. Using the same method, we demonstrate that optically dark GRBs show a consistent evolution as (1+z)^{1.15(+0.67, -0.83)}. By applying the Kolmogorov-Smirnov (KS) test, it is shown that optically dark GRBs have statistically identical flux and photon index distributions compared to normal GRBs, but the NHX is systematically larger. This result suggests that the darkness of some GRB populations is not due to an intrinsic mechanism, but that a higher density surrounds them.

A new phosphorous mononitride ({}^{31}P{}^{14}N, {}^{31}P{}^{15}N) line list PaiN covering infrared, visible and ultraviolet regions is presented. The PaiN line list extending to the A\,{}^{1}\Pi -- X\,{}^{1}\Sigma^{+} vibronic band system, replaces the previous YYLT ExoMol line list for PN. A thorough analysis of high resolution experimental spectra from the literature involving the X\,{}^{1}\Sigma^{+} and A\,{}^{1}\Pi states is conducted, and many perturbations to the A\,{}^{1}\Pi energies are considered as part of a comprehensive MARVEL study. Ab initio potential energy and coupling curves from the previous work [Semenov et al., Phys. Chem. Chem. Phys., 23, 22057 (2021)] are refined by fitting their analytical representations to 1224 empirical energy levels determined using the MARVEL procedure. The PaiN line list is compared to previously observed spectra, recorded and calculated lifetimes, and previously calculated partition functions. The ab initio transition dipole moment curve for the A--X band is scaled to match experimentally measured lifetimes. The line list is suitable for temperatures up to 5000 K and wavelengths longer than 121 nm. PaiN is available from this http URL.

The Pluto-Charon system is a binary system, characterised by its high mass ratio and its tidally locked synchronous orbit. Surrounding the central binary, four satellites - Styx, Nix, Kerberos and Hydra - follow near-circular and near equatorial orbits. Mutual tidal forces have probably a great influence on their long term dynamics. Several studies have pointed out some commensurabilities, sometimes using the fast Fourier transform technique. We intend to precisely identify the commensurabilities between the Pluto-Charon satellites, using the tool of fine frequency analysis, not only to investigate known commensurabilities but also to explore new ones. We used a combination of analytical and numerical approaches. The epicyclic theory of Lee and Peale served as an initial description of the motions and a comparative benchmark for numerical integrations. These integrations were performed using the IAS15 integrator within the N-body orbital integrator, REBOUND, considering both 3-body with the central binary and a single moon, and complete 6-body models. Additionally, we applied Frequency Map Analysis to determine precisely the numerical values of the system's fundamental frequencies. Our fine frequency analysis successfully identified all fundamental frequencies of the system, along with a detailed examination of the associated uncertainties. The findings, obtained with both 3-body and 6-body numerical models, align well with predictions from the epicyclic analytical theory. Notably, we highlight commensurabilities previously reported and introduce novel ones. Furthermore, we demonstrate how smooth alterations of the initial conditions can lead to the observation of libration in specific arguments, providing insights into the dynamical behavior of such a complex system.

Antonio D. Montero-Dorta, Sergio Contreras, M. Celeste Artale, Facundo Rodriguez, Ginevra Favole

The large-scale linear halo bias encodes the relation between the clustering of dark-matter (DM) halos and that of the underlying matter density field. Although the primary dependence of bias on halo mass is well understood in the context of structure formation, the physical origins of the multiple additional relations at fixed halo mass, commonly known as secondary halo bias, have not been fully elucidated. Of particular relevance is the secondary dependence on halo assembly history, known as halo assembly bias. Our goal is to determine whether the properties of the initial regions from which z=0 halos originate produce any secondary bias at z=0. By analyzing these initial dependencies in connection with halo assembly bias, we intend to provide insight on the physical origins of the effect. To this end, we select halos at z=0 in the IllustrisTNG DM-only simulation and trace back the positions and velocities of their DM particles to z=12. The resulting initial regions are characterized according to several shape-related and kinematic properties. The secondary bias signal produced by these properties at z=0 is measured using an object-by-object bias estimator, which offers significant analytical advantages. We show that, when split by the properties of their initial DM clouds, z=0 halos display significant secondary bias, clearly exceeding the amplitude of the well-known halo assembly bias signal produced by concentration and age. The maximum bias segregation is measured for cloud velocity dispersion and radial velocity, followed by cloud concentration, sphericity, ellipticity and triaxiality. We further show that both velocity dispersion and radial velocity are also the properties of the initial clouds that most strongly correlate with halo age and concentration at fixed halo mass. Our results highlight the importance of linear effects in shaping halo assembly bias.

Using a uniform partitioning of cubic cells, we cover the total volume of a \LambdaCDM cosmological simulation based on particles. We define a visualisation cell as a spatial extension of the cubic cell, so that we collect all simulation particles contained in this visualisation cell to create a series of Cartesian plots in which the over-density of matter is clearly visible. We then use these plots as input to a convolutional neural network (CNN) based on the Keras library and TensorFlow for image classification. To assign a class to each plot, we approximate the Hessian of the gravitational potential in the centre of the cubic cells. Each selected cubic cell is then assigned a label of 1,2 or 3, depending on the number of positive eigenvalues obtained for the Householder reduction of the Hessian matrix. We apply the CNN to several models, including two models with different visualisation volumes, one with a cell size of type L (large) and the other with a cell type S (small). A third model that combines the plots of the previous L and S cell types. So far, we have mainly considered a slice parallel to the XY plane to make the plots. The last model is considered based on visualisations of cells that also include slices parallel to the ZX and ZY planes. We find that the accuracy in classificating plots is acceptable, and the ability of the models to predict the class works well. These results allow us to demonstrate the aim of this paper, namely that the usual Cartesian plots contain enough information to identify the observed structures of the cosmic web.

Vandana Ramakrishnan, Kyoung-Soo Lee, Nicole Firestone, Eric Gawiser, Maria Celeste Artale, Caryl Gronwall, Lucia Guaita, Sang Hyeok Im, Woong-Seob Jeong, Seongjae Kim, Ankit Kumar, Jaehyun Lee, Byeongha Moon, Nelson Padilla, Changbom Park, Hyunmi Song, Paulina Troncoso, Yujin Yang

The One-hundred-deg^2 DECam Imaging in Narrowbands (ODIN) survey is carrying out a systematic search for protoclusters during Cosmic Noon, using Ly\alpha-emitting galaxies (LAEs) as tracers. Once completed, ODIN aims to identify hundreds of protoclusters at redshifts of 2.4, 3.1, and 4.5 across seven extragalactic fields, covering a total area of up to 91~deg^2. In this work, we report strong clustering of high-redshift protoclusters through the protocluster-LAE cross-correlation function measurements of 150 protocluster candidates at z~=~2.4 and 3.1, identified in two ODIN fields with a total area of 13.9 deg^2. At z~=~2.4 and 3.1, respectively, the inferred protocluster biases are 6.6^{+1.3}_{-1.1} and 6.1^{+1.3}_{-1.1}, corresponding to mean halo masses of \log \langle M /M_\odot\rangle = 13.53^{+0.21}_{-0.24} and 12.96^{+0.28}_{-0.33}. By the present day, these protoclusters are expected to evolve into virialized galaxy clusters with a mean mass of \sim 10^{14.5}~M_\odot. By comparing the observed number density of protoclusters to that of halos with the measured clustering strength, we find that our sample is highly complete. Finally, the similar descendant masses derived for our samples at z=2.4 and 3.1 assuming that the halo number density remains constant suggest that they represent similar structures observed at different cosmic epochs. As a consequence, any observed differences between the two samples can be understood as redshift evolution. The ODIN protocluster samples will thus provide valuable insights into the cosmic evolution of cluster galaxies.

A. Kundu, Jagdish C. Joshi, C. Venter, N. E. Engelbrecht, W. Zhang, Diego F. Torres, I. Sushch, Shuta J. Tanaka

Recent observations of a few young pulsar wind nebulae (PWNe) have revealed their morphologies in some detail. Given the availability of spatio-spectral-temporal data, we use our multi-zone (1D) leptonic emission code to model the PWNe associated with G29.7-0.3 (Kes 75) and G21.5-0.9 (G21.5) and obtain (by-eye) constraints on additional model parameters compared to spectral-only modelling. Kes 75 is a Galactic composite supernova remnant (SNR) with an embedded pulsar, PSR J1846-0258. X-ray studies reveal rapid expansion of Kes 75 over the past two decades. PWN G21.5 is also a composite SNR, powered by PSR J1833-1034. For Kes 75, we study a sudden plasma bulk speed increase that may be due to the magnetar-like outbursts of the central pulsar. An increase of a few percent in this speed does not result in any significant change in the model outputs. For G21.5, we investigate different diffusion coefficients and pulsar spin-down braking indices. We can reproduce the broadband spectra and X-ray surface brightness profiles for both PWNe, and the expansion rate, flux over different epochs, and X-ray photon index vs epoch and central radius for Kes 75 quite well. The latter three features are also investigated for G21.5. Despite obtaining reasonable fits overall, some discrepancies remain, pointing to further model revision. We find similar values to overlapping parameters between our 1D code and those of an independent 0D dynamical code (TIDE). Future work will incorporate spatial data from various energy wavebands to improve model constraints.

Radio spectral shape of quasars can provide insight into the ages of quasars. We have compiled data for 1804 quasars with z\lesssim1 from the Sloan Digital Sky Survey (SDSS). Additionally, these quasars were also mapped by the Low-Frequency Array at 144 MHz and the Very Large Array Sky Survey at 3000 MHz. The radio spectral index, designated as \alpha^{\rm 144}_{\rm 3000} (with S(\nu)\propto\nu^\alpha), is analyzed between 144 MHz and 3000 MHz as a proxy for the ages of quasars. We measure the [O III] \lambda5007 emission line in the SDSS spectra. A strong correlation was found between the equivalent width of the core component of the [O III] \lambda5007 emission line and \alpha^{\rm 144}_{\rm 3000}. This relationship suggests that the core component of the [O III] \lambda5007 emission line could potentially serve as a surrogate for the evolutionary stage of a quasar. The quasars at an early stage of evolutions tend to show weaker [O III] \lambda5007 emission, while older quasars exhibit stronger [O III] \lambda5007 emission.

Quasars are bright active galactic nuclei powered by the accretion of matter around supermassive black holes at the center of galaxies. Their stochastic brightness variability depends on the physical properties of the accretion disk and black hole. The upcoming Rubin Observatory Legacy Survey of Space and Time (LSST) is expected to observe tens of millions of quasars, so there is a need for efficient techniques like machine learning that can handle the large volume of data. Quasar variability is believed to be driven by an X-ray corona, which is reprocessed by the accretion disk and emitted as UV/optical variability. We are the first to introduce an auto-differentiable simulation of the accretion disk and reprocessing. We use the simulation as a direct component of our neural network to jointly model the driving variability and reprocessing to fit simulated LSST 10-year quasar light curves. The driving variability is reconstructed using a latent stochastic differential equation, a physically motivated, generative deep learning method that can model continuous-time stochastic dynamics. By embedding these physical processes into our network, we achieve a model that is more robust and interpretable. We also use transformers to scale our model to tens of millions of parameters. We demonstrate how our model outperforms a Gaussian process regression baseline and can infer accretion disk parameters and time delays between wavebands, even for out-of-distribution driving signals. Our approach provides a powerful and scalable framework that can be adapted to solve other inverse problems in multivariate time series with irregular sampling.

Athira Unni, Thirupathi Sivarani, Jayesh Goyal, Yogesh C. Joshi, Apurva V. Oza, Ravinder K Banyal

Here, we present the low-resolution transmission spectroscopy of three giant planets using the Himalayan Faint Object Spectrograph Camera (HFOSC) on the 2m Himalayan Chandra Telescope (HCT) in Hanle, India. It is the first application of transmission spectroscopy with HCT. This study presents results from a single transit, each for three planets: HAT-P-1b, KELT- 18b and WASP-127b. The selection of suitable reference stars assisted in accurately tracking slit losses for the long cadence observations that are needed to achieve the required Signal to Noise Ratio (SNR). We employ the Common Mode Correction (CMC) technique, utilizing a white light transit curve to minimize time dependent systematic errors. The observed spectra for WASP-127b and HAT-P-1b agree with previous low-resolution transit spectroscopic observations using other observing facilities. We confirm the presence of Rayleigh scattering in the atmosphere of WASP-127b. In addition, we provide the first low-resolution transmission spectrum for KELT-18b. Modeling the exoplanet atmosphere with HFOSC and available IR observations from HST and SPITZER for WASP-127b and HAT-P-1b shows that HFOSC can be an alternative optical instrument to use in conjunction with IR observations to constrain the atmospheric parameters better.

[Abridged] The [OIII]_{88\mu m}/[CII]_{158\mu m} and [OIII]_{88\mu m}/[NII]_{122\mu m} luminosity ratios have shown to be promising tracers of the ionisation state and gas-phase metallicity of the ISM. Observations of galaxies at redshift z > 6 show peculiarly higher [OIII]_{88\mu m}/[CII]_{158\mu m} luminosity ratios compared to local sources. No model has so far successfully managed to match the observed emission from both [OIII]_{88\mu m} and [CII]_{158\mu m} as well as their ratio. We use Cloudy to model the [CII]_{158\mu m}, [OIII]_{88\mu m}, [NII]_{122\mu m} and [NIII]_{57\mu m} emission lines of Ponos: a high-resolution (m_{\mathrm{gas}} = 883.4\, M_{\odot}) cosmological zoom-in simulation of a galaxy at redshift z = 6.5, which is post-processed using kramses-rt. We modify Carbon, Nitrogen and Oxygen abundances in our Cloudy models to obtain C/O and N/O abundance ratios respectively lower and higher than Solar, more in line with recent high-z observational constraints. We find [OIII]_{88\mu m}/[CII]_{158\mu m} luminosity ratios that are a factor of \sim 5 higher compared to models assuming solar abundances. Additionally, we find an overall better agreement of the simulation with high-z observational constraints of the [CII]_{158\mu m}-SFR and [OIII]_{88\mu m}-SFR relations. This shows that a lower C/O abundance ratio is essential to reproduce the enhanced [OIII]_{88\mu m}/[CII]_{158\mu m} luminosity ratios observed at z > 6. By assuming a super-solar N/O ratio, motivated by recent z > 6 JWST observations, our models yield an [OIII]_{88\mu m}/[NII]_{122\mu m} ratio of 1.3, which, according to current theoretical models, would be more appropriate for a galaxy with a lower ionisation parameter than the one we estimated for Ponos.

A recent analysis on the properties of XTE J18014-338 yielded a surprising radius value around ~ 7 km. Notably, this estimation is significantly lower compared to the expected values for the radius of neutron stars, which are derived from both theoretical calculations and corresponding observations. In this letter, we focus on the construction of hybrid equations of state for the possible reconciliation of the exotic XTE J18014-338 properties. Our analysis indicates that an equation of state involving a sufficiently strong phase transition could potentially lead to the explanation of the size and mass of such a compact object. By examining the sign of the dM/dP_c slope, we found that stellar configurations compatible to XTE J18014-338 are only stable for a 'stiff' low density phase. For a 'soft' hadronic EOS selection the stability of the resulting configurations may not be satisfied in terms of the turning point criterion. However, a complementary analysis for the radial oscillations of the aforementioned configurations indicates their stability when a slow phase conversion is considered.

Matthias U. Kruckow, Jeff J. Andrews, Tassos Fragos, Berry Holl, Simone S. Bavera, Max Briel, Seth Gossage, Konstantinos Kovlakas, Kyle A. Rocha, Meng Sun, Philipp M. Srivastava, Zepei Xing, Emmanouil Zapartas

Context. The black holes discovered using Gaia, especially Gaia BH1 and BH2, have low mass companions of solar-like metallicity in wide orbits. For standard isolated binary evolution formation channels including interactions such an extreme mass ratio is unexpected; especially in orbits of hundreds to thousands of days. Aims. Here, we investigate a non-interacting formation path for isolated binaries to explain the formation of Gaia BH1 and BH2. Methods. We use single star models computed with MESA to constrain the main characteristics of possible progenitors of long-period black hole binaries like Gaia BH1 and BH2. Then, we incorporate these model grids into the binary population synthesis code POSYDON, to explore whether the formation of the observed binaries at solar metallicity is indeed possible. Results. We find that winds of massive stars (\gtrsim 80\,M_\odot), especially during the Wolf-Rayet phase, tend to cause a plateau in the initial stellar mass to final black hole mass relation (at about 13\,M_\odot in our default wind prescription). However, stellar winds at earlier evolutionary phases are also important at high metallicity, as they prevent the most massive stars from expanding (<100\,R_\odot) and filling their Roche lobe. Consequently, the strength of the applied winds affects the range of the final black hole masses in non-interacting binaries, making it possible to form systems similar to Gaia BH1 and BH2. Conclusions. We deduce that wide binaries with a black hole and a low mass companion can form at high metallicity without binary interactions. There could be hundreds of such systems in the Milky Way. The mass of the black hole in binaries evolved through the non-interacting channel can potentially provide insights into the wind strength during the progenitors evolution.

Xu Ding, KaiFan Ji, ZhiMing Song, NianPing Liu, JianPing Xiong, QiYuan Cheng, ChuanJun Wang, JinLiang Wang, DeQing Wang, ShouSheng He

TIC 157365951 has been classified as a \delta Scuti type by the International Variable Star Index (VSX). Through the spectra from Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) and its light curve, we further discovered that it is a binary system. This binary system comprises a red dwarf star and a compact star. Through the spectral energy distribution (SED) fitting, we determined the mass of the red dwarf star as M_1 = 0.31 \pm 0.01 M_{\odot} and its radius as R_1 = 0.414 \pm 0.004 R_{\odot}. By fitting the double-peaked H{\rm \alpha} emission, we derived the mass ratio of q = 1.76 \pm 0.04 , indicating a compact star mass of M_2 = 0.54 \pm 0.01 M_{\odot}. Using Phoebe to model the light curve and radial velocity curve for the detached binary system, we obtained a red dwarf star mass of M_1 = 0.29 \pm 0.02 M_{\odot}, a radius of R_1 = 0.39 \pm 0.04 R_{\odot}, and a Roche-lobe filling factor of f = 0.995\pm0.129, which is close to the f=1 expected for a semi-detached system. The Phoebe model gives a compact star mass M_2 = 0.53 \pm 0.05 M_{\odot}. Constraining the system to be semidetached gives M_1 = 0.34 \pm 0.02 M_{\odot}, R_1 = 0.41 \pm 0.01 R_{\odot}, and M_2 = 0.62 \pm 0.03 M_{\odot}. The consistency of the models is encouraging. The value of the Roche-lobe filling factor suggests that there might be ongoing mass transfer. The compact star mass is as massive as a typical white dwarf.

Josh Calcino, Daniel J. Price, Thomas Hilder, Valentin Christiaens, Jessica Speedie, Chris W. Ormel

Late-stage infall onto evolved protoplanetary discs is an important source of material and angular momentum replenishment, and disc substructures. In this paper we used 3D smoothed particle hydrodynamics simulations to model streamer-disc interactions for a prograde streamer. The initially parabolic streamer interacts with the disc material to excite disc eccentricity, which can last on the order of 10^5 years. We found that the spiral arms the streamer excited in the disc can have a variety of pattern speeds, ranging from stationary to super-Keplerian. Spiral arms with various pattern speeds can exist simultaneously, providing a way to diagnose them in observations. Streamer induced spirals appear similar to those generated by a massive outer companion, where the pitch angle of the spiral increases towards the source of the perturbation. Additionally, the spirals arms can show large and sudden pitch angle changes. Streamer induced spirals are long-lived, lasting approximately 3-4\times longer than the initial streamer infall timescale (\sim10^4 years). After the initial interaction with the disc, a long lasting low m azimuthal mode persists in the disc.

The baryon acoustic oscillation (BAO) reconstruction plays a crucial role in cosmological analysis for spectroscopic galaxy surveys because it can make the density field effectively more linear and more Gaussian. The combination of the power spectra before and after the BAO reconstruction helps break degeneracies among parameters, then improve the constraints on cosmological parameters. It is therefore important to estimate the covariance matrix between pre- and post-reconstructed power spectra. In this work, we use perturbation theory to estimate the covariance matrix of the related power spectra multipoles, and check the accuracy of the derived covariance model using a large suite of dark matter halo catalogs at z=0.5. We find that the diagonal part of the auto covariance is well described by the Gaussian prediction, while the cross covariance deviates from the Gaussian prediction quickly when k > 0.1\,h\,\mathrm{Mpc}^{-1}. Additionally, we find the non-Gaussian effect in the non-diagonal part of the cross covariance is comparable to, or even stronger than the pre-reconstruction covariance. By adding the non-Gaussian contribution, we obtain good agreement between analytical and numerical covariance matrices in the non-diagonal part up to k \simeq 0.15\,h\,\mathrm{Mpc}^{-1}. The agreement in the diagonal part is also improved, but still under-predicts the correlation in the cross covariance block.

Shantanu Jain, Tatiana Podladchikova, Astrid M. Veronig, Galina Chikunova, Karin Dissauer, Mateja Dumbovic, Amaia Razquin

arXiv:2311.13942

On May 8, 2024, solar active region 13664 produced an X-class flare, several M-class flares, and multiple Earth-directed Coronal Mass Ejections (CMEs). The initial CME caused coronal dimmings, characterized by localized reductions in extreme-ultraviolet (EUV) emissions, indicating mass loss and expansion during the eruption. After one solar rotation, on June 8, 2024, the same region produced another M-class flare followed by coronal dimmings observed by the SDO and STEREO spacecraft. We analyzed early CME evolution and direction from coronal dimming expansion at the end of the impulsive phase using the DIRECD (Dimming Inferred Estimation of CME Direction) method. To validate the 3D CME cone, we compared CME properties from the low corona with white-light coronagraph data. The May 8 CME expanded radially, with a 7.7 deg inclination, 70 deg angular width, and 0.81 Rsun cone height, while the June 8 CME had a 15.7 deg inclination, 81 deg width, and 0.89 Rsun height. Our study shows that tracking low coronal signatures, like coronal dimming expansion, can estimate CME direction early, providing crucial lead time for space weather forecasts.

Xuebao Li, Xuefeng Li, Yanfang Zheng, Ting Li, Pengchao Yan, Hongwei Ye, Shunhuang Zhang, Xiaotian Wang, Yongshang Lv, Xusheng Huang

The existing flare prediction primarily relies on photospheric magnetic field parameters from the entire active region (AR), such as Space-Weather HMI Activity Region Patches (SHARP) parameters. However, these parameters may not capture the details the AR evolution preceding flares. The magnetic structure within the core area of an AR is essential for predicting large solar flares. This paper utilizes the area of high photospheric free energy density (HED region) as a proxy for the AR core region. We construct two datasets: SHARP and HED datasets. The ARs contained in both datasets are identical. Furthermore, the start and end times for the same AR in both datasets are identical. We develop six models for 24-hour solar flare forecasting, utilizing SHARP and HED datasets. We then compare their categorical and probabilistic forecasting performance. Additionally, we conduct an analysis of parameter importance. The main results are as follows: (1) Among the six solar flare prediction models, the models using HED parameters outperform those using SHARP parameters in both categorical and probabilistic prediction, indicating the important role of the HED region in the flare initiation process. (2) The Transformer flare prediction model stands out significantly in True Skill Statistic (TSS) and Brier Skill Score (BSS), surpassing the other models. (3) In parameter importance analysis, the total photospheric free magnetic energy density (\mathrm {E_{free}}) within the HED parameters excels in both categorical and probabilistic forecasting. Similarly, among the SHARP parameters, the R_VALUE stands out as the most effective parameter for both categorical and probabilistic forecasting.

Christian J. Renggli, Edgar S. Steenstra, Alberto E. Saal

This chapter presents a comprehensive overview of the abundances and distribution of S, and the processes that control the behavior of S on the Earth's Moon and on Mercury. The two planetary bodies share notable similarities, such as lacking substantial atmospheres and featuring surfaces with high numbers of impact craters. Both objects are at variably low oxygen fugacities (fO2), where S occurs only in its reduced state as S2-, and forms sulfides. For the Moon, we present a compilation of 55 years of lunar sample analysis, from Apollo 11 to Chang'e 5, including S concentrations and isotopic compositional data. We discuss processes from S in the lunar interior to volcanic degassing from mare basalts and in pyroclastic eruptions. At the beginning of a lunar science renaissance, we highlight where future research into S on the Moon might lead. The knowledge of S on Mercury is almost entirely based on observations by the NASA MESSENGER mission, operational from 2011 to 2014. MESSENGER observed very high S abundances on Mercury with concentrations of up to 4 wt.%. We discuss proposed mechanisms that lead to the high S abundance on Mercury's surface and discuss implications for the planet's interior. Finally, we provide an outlook on how the upcoming ESA/JAXA BepiColombo will advance our understanding of Mercury and the processes controlling S on the planet.

Michela Rigoselli, Caterina Tresoldi, Lorenzo Ducci, Sandro Mereghetti

A0538-66 is a neutron star/Be X-ray binary located in the Large Magellanic Cloud and, since its discovery in the seventies, it showed a peculiar behavior which makes it a unique object in the high-mass X-ray binaries scene: the extremely eccentric orbit (e=0.72), the short spin period of the neutron star (P=69 ms), the episodes of super-Eddington accretion. These characteristics contribute to a remarkable bursting activity that lasts from minutes to hours and increases the flux by a factor 10^3-10^4. In 2018, A0538-66 was observed by XMM-Newton in a particularly active state, characterized by a forest of short bursts lasting 0.7-50 seconds each. In this contribution we present a reanalysis of these observations. The timing analysis allowed us to distinguish between the epochs of direct accretion and propeller state, that do not correlate with the orbital position of the neutron star. The spectral analysis revealed that during the accretion regime three components (a soft one, a hard one, and a ~6.4-keV emission line) equally contribute to the overall emission, while the propeller regime is characterized by a single soft component. We discuss these findings in the context of spherical and disk accretion regimes, highlighting the similarities and the differences with other X-ray binary systems.

Rosa E. Keers, Alexander I. Shapiro, Nadiia M. Kostogryz, Ana Glidden, Prajwal Niraula, Benjamin V. Rackham, Sara Seager Sami K. Solanki, Yvonne C. Unruh, Valeriy Vasilyev, Julien de Wit

Stellar limb darkening must be properly accounted for to accurately determine the radii of exoplanets at various wavelengths. The standard approach to address limb darkening involves either using laws with coefficients from modelled stellar spectra or determining the coefficients empirically during light curve fitting of the data. Here, we test how accurately three common laws -- quadratic, power, and a three-parameter law -- can reproduce stellar limb darkening at different wavelengths and across a broad range of stars. We show that using a quadratic limb darkening law, which is most frequently employed by the community, leads to wavelength-dependent offsets in retrieved transmission spectra. For planets with high impact parameters (b larger than about 0.5) the amplitude of these offsets can reach 1\% of the transit depth which is some cases is comparable to and can even exceed the expected signals from the planetary atmosphere. Furthermore, the quadratic law causes an offset in the value of the impact parameter when it is determined by fitting the broadband transit light curves. In contrast, using the Kipping--Sing three-parameter law leads to robust retrievals. We advocate the use of this law in retrievals, especially for transits with large impact parameters.

G. Rojas García, D. Graczyk, G. Pietrzyński, C. Gałan, W. Gieren, I. Thompson, K. Suchomska, M. Kałuszyński, I. Soszyński, A. Udalski, P. Karczmarek, W. Narloch, M. Górski, P. Wielgórski, B. Zgirski, N. Miller, G. Hajdu, B. Pilecki, M. Taormina, M. Lewis

Detached eclipsing binaries (DEBs) allow for the possibility of precise characterization of its stellar components. They offer a unique opportunity to derive their physical parameters in a near-model-independent way for a number of systems consisting of late-type giant stars. Here we aim to expand the sample of low-metallicity late-type giant stars with precise parameters determined. We aim to determine the fundamental parameters like the mass, radius, or effective temperature for three long-period late-type eclipsing binaries from the Large Magellanic Cloud: OGLE-LMC-ECL-25304, OGLE-LMC-ECL-28283, and OGLE-IV LMC554.19.81. Subsequently we aim to determine the evolutionary stages of the this http URL fit the light curves from the OGLE project and radial velocity curves from high resolution spectrographs using the Wilson-Devinney code. The spectral analysis was performed with the GSSP code and resulted in the determination of atmospheric parameters such as effective temperatures and metallicities. We used isochrones provided by the MIST models based on the MESA code to derive evolutionary status of the stars. We present the first analysis of three DEBs composed of similar He-burning late-type stars passing through the blue loop. Estimated masses for OGLE-LMC-ECL-29293 (G4III + G4III) are M_1=2.898\pm0.031 and M_2=3.153\pm0.038 M_\odot, stellar radii are R_1=19.43\pm0.31 and R_2=19.30\pm0.31 R_\odot. OGLE-LMC-ECL-25304 (G4III + G5III) has stellar masses of M_1=3.267\pm0.028 and M_2=3.229\pm0.029 M_\odot, radii of R_1=23.62\pm0.42 and R_2=25.10\pm0.43 R_\odot. OGLE-IV LMC554.19.81 (G2III + G2III) have masses of M_1=3.165\pm0.020 and M_2=3.184\pm0.020 M_\odot, radii of R_1=18.86\pm0.26 and R_2=19.64\pm0.26 R_\odot. All masses were determined with a precision better than 2\% and radii better than 1.5\%. The ages of the stars are in the range of 270-341 Myr.

Jose Beltrán Jiménez, Dario Bettoni, David Figueruelo, Florencia A. Teppa Pannia

The increasing quality of cosmological data has revealed some tensions that could be signalling the necessity of incorporating new physics into our cosmological model. One particularly intriguing possibility is the existence of elastic interactions between dark matter and dark energy. Not only do these interactions provide a natural mechanism to relief cosmological tensions, but there is also compelling observational evidence for them, to the extent that a detection could even be claimed. We review the potential of these scenarios in relation to the cosmological tensions and discuss distinctive signatures that can be probed with future data, thus providing a smoking gun for these interactions.

Gabriel d'Andrade Furlanetto, Riccardo Della Monica, Ivan De Martino

Fuzzy Dark Matter (FDM) is among the most suitable candidates to replace WIMPs and to resolve the puzzling mystery of dark matter. A galactic dark matter halo made of these ultralight bosonic particles leads to the formation of a solitonic core surrounded by quantum interference patterns that, on average, reproduce a Navarro-Frenk-White-like mass density profile in the outskirts of the halo. The structure of such a core is determined once the boson mass and the total mass of the halo are set. We investigated the capability of future astrometric Theia-like missions to detect the properties of such a halo within the FDM model, namely the boson mass and the core radius. To this aim, we built mock catalogs containing three-dimensional positions and velocities of stars within a target dwarf galaxy. We exploited these catalogs using a Markov Chain Monte Carlo algorithm and found that measuring the proper motion of at least 2000 stars within the target galaxy, with uncertainty \sigma_v \leq 3 km/s on the velocity components, will constrain the boson mass and the core radius with 3\% accuracy. Furthermore, the transition between the solitonic core and the outermost NFW-like density profile could be detected with an uncertainty of 7\%. Such results would not only help to confirm the existence of FDM, but they would also be useful for alleviating the current tension between galactic and cosmological estimations of the boson mass, or demonstrating the need for multiple particles with a broad mass spectrum as naturally arise String Axiverse.

D. J. M. Petit dit de la Roche, H. Chakraborty, M. Lendl, D. Kitzmann, A. G. M. Pietrow, B. Akinsanmi, H. M. J. Boffin, Patricio E. Cubillos, A. Deline, D. Ehrenreich, L. Fossati, E. Sedaghati

Context: Transmission spectroscopy is a powerful tool for understanding exoplanet atmospheres. At optical wavelengths, it makes it possible to infer the composition and the presence of aerosols in the atmosphere. However, unocculted stellar activity can result in contamination of atmospheric transmission spectra by introducing spurious slopes and molecular signals. Aims: We aim to characterise the atmosphere of the transiting exoplanet WASP-69b, a hot Jupiter orbiting an active K star, and characterise the host star's activity levels. Methods: We obtained three nights of spectrophotometric data with the FORS2 instrument on the VLT, covering a wavelength range of 340-1100 nm. We performed retrievals on the full spectrum with combined stellar activity and planet atmosphere models. Results: We directly detect a facula in the form of a hot spot crossing event in one of the transits and indirectly detect unocculted faculae through an apparently decreasing radius towards the blue end of the transmission spectrum. We determine a facula temperature of \Delta T=+644^{+427}_{-263} K for the former and a stellar coverage fraction of around 30% with a temperature of \Delta T=+231\pm72 K for the latter. The planetary atmosphere is best fit with a high-altitude cloud deck at 1.4 mbar that mutes atomic and molecular features. We find indications of water and ammonia with log(H_2O)=-2.01^{+0.54}_{-0.86} and log(NH_3)=-3.4^{+0.96}_{-5.20} respectively and place 3\sigma upper limits on TiO (10^{-7.65}) and K (10^{-7}$). Conclusions. The simultaneous multi-wavelength observations allow us to break the size-contrast degeneracy for facula-crossings, meaning we can obtain temperatures for both the directly and indirectly detected faculae, which are consistent with each other.

A. J. Goodwin, A. Mummery, T. Laskar, K. D. Alexander, G. E. Anderson, M. Bietenholz, C. Bonnerot, C. T. Christy, W. Golay, W. Lu, R. Margutti, J. C. A. Miller-Jones, E. Ramirez-Ruiz, R. Saxton, S. van Velzen

We present the discovery of a second radio flare from the tidal disruption event (TDE) AT2020vwl via long-term monitoring radio observations. Late-time radio flares from TDEs are being discovered more commonly, with many TDEs showing radio emission 1000s of days after the stellar disruption, but the mechanism that powers these late-time flares is uncertain. Here we present radio spectral observations of the first and second radio flares observed from the TDE AT2020vwl. Through detailed radio spectral monitoring, we find evidence for two distinct outflow ejection episodes, or a period of renewed energy injection into the pre-existing outflow. We deduce that the second radio flare is powered by an outflow that is initially slower than the first flare, but carries more energy and accelerates over time. Through modelling the long-term optical and UV emission from the TDE as arising from an accretion disc, we infer that the second radio outflow launch or energy injection episode occurred approximately at the time of peak accretion rate. The fast decay of the second flare precludes environmental changes as an explanation, while the velocity of the outflow is at all times too low to be explained by an off-axis relativistic jet. Future observations that search for any link between the accretion disc properties and late time radio flares from TDEs will aid in understanding what powers the radio outflows in TDEs, and confirm if multiple outflow ejections or energy injection episodes are common.

Andreas Wagner, Daniel J. Price, Slava Bourgeois, Farhad Daei, Jens Pomoell, Stefaan Poedts, Anshu Kumari, Teresa Barata, Robertus Erdélyi, Emilia K. J. Kilpua

We investigate the effect of data-driving on flux rope eruptivity in magnetic field simulations by analysing fully data-driven modelling results of active region (AR) 12473 and AR11176, as well as preforming relaxation runs for AR12473 (found to be eruptive). Here, the driving is switched off systematically at different time steps. We analyse the behaviour of fundamental quantities, essential for understanding the eruptivity of magnetic flux ropes (MFRs). The data-driven simulations are carried out with the time-dependent magnetofrictional model (TMFM) for AR12473 and AR11176. For the relaxation runs, we employ the magnetofrictional method (MFM) and a zero-beta magnetohydrodynamic (MHD) model to investigate how significant the differences between the two relaxation procedures are when started from the same initial conditions. To determine the eruptivity of the MFRs, we calculate characteristic geometric properties, such as the cross-section, MFR height along with stability parameters, such as MFR twist and the decay index. For eruptive cases, we investigate the effect of sustained driving beyond the point of eruptivity on the MFR properties. We find that the fully-driven AR12473 MFR is eruptive while the AR11176 MFR is not. For the relaxation runs, we find that the MFM MFRs are eruptive when the driving is stopped around the flare time or later, while the MHD MFRs show eruptive behaviour even if the driving is switched off one and a half days before the flare occurs. We find that characteristic MFR properties can vary greatly even for the eruptive cases of different relaxation simulations. The results suggest that data driving can significantly influence the evolution of the eruption, with differences appearing even when the relaxation time is set to later stages of the simulation when the MFRs have already entered an eruptive phase.

Maialen Orte-García, César Esteban, José Eduardo Méndez-Delgado, Jorge García-Rojas

Chlorine (Cl) is a chemical element of the group of the halogens and is between the 17th and the 20th most abundant elements in the Solar System. It is thought to be produced from the capture of a proton or neutron by specific alpha-element isotopes during both hydrostatic and explosive oxygen burning, though some contribution may come from Type Ia supernovae. Cl lines are quite rare in stellar spectra, so most of the information available about its abundance comes from analyzing the emission lines of ionized nebulae, especially the collisionally excited lines of Cl2+ ([Cl III] {\lambda}{\lambda}5518,5538). Our goal is to accurately determine the Cl abundance in H II regions, and gather more information about its nucleosynthetic origin. For this work we used a sample of observations that encompasses the deepest spectra of H II regions available in the literature, from both the Milky Way and other galaxies in the local Universe, covering a range of oxygen (O) abundances, 12+log(O/H), from 7.18 to 8.70. As a first step, we determine the most representative electron temperature of the zone of the nebulae where the Cl2+ ion lies. To this aim we used a grid of photoionization models and diagnostics valid for other ions, as that parameter cannot be determined directly through [Cl III] lines. We then computed the total Cl abundance using different sets of ionization correction factors to account for the contribution from unseen ionization stages.

This study presents an analysis of the optical variability of the blazar 1E 1458.8+2249 on diverse timescales using multi-band observations, including observations in the optical BVRI bands carried out with the T60 and T100 telescopes from 2020 to 2023 and ZTF gri data from 2018 to 2023. On seven nights, we searched for intraday variability using the power-enhanced F-test and the nested ANOVA test, but no significant variability was found. The long-term light curve shows a variability behaviour in the optical BVRI bands with amplitudes of \sim100\% and in the gri bands with amplitudes of \sim120\%, including short-term variability of up to \sim1.1 mag. Correlation analysis revealed a strong correlation between the optical multi-band emissions without any time this http URL 62 nightly SEDs, we obtained spectral indices between 0.826 and 1.360, with an average of 1.128\pm0.063. The relationships of both spectral indices and colour with respect to brightness indicate a mild BWB trend throughout the observation period, both intraday and long-term. We also performed a periodicity search using the Weighted Wavelet Z-transform (WWZ) and Lomb-Scargle methods. A recurrent optical emission pattern with a quasi-periodicity of \sim340 days is detected in the combined V- and R-band light curves. The observational results indicate that the blazar 1E 1458.8+2249 has a complex variability, while emphasising the need for future observations to unravel its underlying mechanisms.

Itay M. Bloch, Ana M. Botti, Mariano Cababie, Gustavo Cancelo, Brenda A. Cervantes-Vergara, Miguel Daal, Ansh Desai, Alex Drlica-Wagner, Rouven Essig, Juan Estrada, Erez Etzion, Guillermo Fernandez Moroni, Stephen E. Holland, Jonathan Kehat, Ian Lawson, Steffon Luoma, Aviv Orly, Santiago E. Perez, Dario Rodrigues, Nathan A. Saffold, Silvia Scorza, Miguel Sofo-Haro, Kelly Stifter, Javier Tiffenberg, Sho Uemura, Edgar Marrufo Villalpando, Tomer Volansky, Federico Winkel, Yikai Wu, Tien-Tien Yu

We present results from data acquired by the SENSEI experiment at SNOLAB after a major upgrade in May 2023, which includes deploying 16 new sensors and replacing the copper trays that house the CCDs with a new light-tight design. We observe a single-electron event rate of (1.39 \pm 0.11) \times 10^{-5} e^-/pix/day, corresponding to (39.8 \pm 3.1) e^-/gram/day. This is an order-of-magnitude improvement compared to the previous lowest single-electron rate in a silicon detector and the lowest for any photon detector in the near-infrared-ultraviolet range. We use these data to obtain a 90% confidence level upper bound of 1.53 \times 10^{-5} e^-/pix/day and to set constraints on sub-GeV dark matter candidates that produce single-electron events. We hypothesize that the data taken at SNOLAB in the previous run, with an older tray design for the sensors, contained a larger rate of single-electron events due to light leaks. We test this hypothesis using data from the SENSEI detector located in the MINOS cavern at Fermilab.

Lorenzo Napolitano, Marco Castellano, Laura Pentericci, Cristian Vignali, Roberto Gilli, Adriano Fontana, Paola Santini, Tommaso Treu, Antonello Calabrò, Mario Llerena, Enrico Piconcelli, Luca Zappacosta, Sara Mascia, Pietro Bergamini, Tom J.L.C. Bakx, Mark Dickinson, Karl Glazebrook, Alaina Henry, Nicha Leethochawalit, Giovanni Mazzolari, Emiliano Merlin, Takahiro Morishita, Themiya Nanayakkara, Diego Paris, Simonetta Puccetti, Guido Roberts-Borsani, Sofia Rojas Ruiz, Eros Vanzella, Fabio Vito, Benedetta Vulcani, Xin Wang, Ilsang Yoon, Jorge A. Zavala

We present JWST/NIRSpec PRISM spectroscopic characterization of GHZ9 at z= 10.145 \pm 0.010, currently the most distant source detected by the Chandra X-ray Observatory. The spectrum reveals several UV high-ionization lines, including CII, SiIV, [NIV], CIV, HeII, OIII], NIII], and CIII]. The prominent rest-frame equivalent widths (EW(CIV)\simeq65A, EW(HeII)\simeq18A, EW(CIII])\simeq48A) show the presence of a hard radiation field, while the analysis of line ratio diagnostics suggest this galaxy hosts both AGN and star-formation activity. GHZ9 is nitrogen-enriched (6--9.5 times solar), carbon-poor (0.2--0.65 times solar), metal-poor (Z = 0.01--0.1 Z_{\odot}), and compact (< 106 pc), similarly to GNz11, GHZ2, and recently discovered N-enhanced high redshift objects. We exploited the newly available JWST/NIRSpec and NIRCam dataset to perform an independent analysis of the Chandra data confirming that GHZ9 is the most likely JWST source associated to X-ray emission at 0.5-7 keV. Assuming a spectral index \Gamma = 2.3 (1.8), we estimate a black hole (BH) mass of 1.60 \pm 0.31 (0.48 \pm 0.09) \times 10^8M_{\odot}, which is consistent either with Eddington-accretion onto heavy (\geq 10^6 M_{\odot}) BH seeds formed at z=18, or super-Eddington accretion onto a light seed of \sim 10^2-10^4 M_{\odot} at z = 25. The corresponding BH-to-stellar mass ratio M_{BH}/M_{star}= 0.33\pm0.22 (0.10\pm0.07), with a stringent limit >0.02, implies an accelerated growth of the BH mass with respect to the stellar mass. GHZ9 is the ideal target to constrain the early phases of AGN-galaxy coevolution with future multi-frequency observations.

Antonio Vecchio, Milan Maksimovic, Nicolina Chrysaphi, Eduard P. Kontar, Vratislav Krupar

Radio observations from space allow to characterize solar radio bursts below the ionospheric cutoff, which are otherwise inaccessible, but suffer from low, insufficient temporal resolution. In this Letter we present novel, high-temporal resolution observations of type III solar radio bursts in the range 3-13 MHz. A dedicated configuration of the Radio and Plasma Waves (RPW) High Frequency Receiver (HFR) on the Solar Orbiter mission, allowing for a temporal resolution as high as \sim0.07s (up to 2 orders of magnitude better than any other spacecraft measurements), provides for the very first time resolved measurements of the typical decay time values in this frequency range. The comparison of data with different time resolutions and acquired at different radial distances indicates that discrepancies with decay time values provided in previous studies are only due to the insufficient time resolution not allowing to accurately characterize decay times in this frequency range. The statistical analysis on a large sample of \sim500 type III radio bursts shows a power low decay time trend with a spectral index of -0.75\pm0.03 when the median values for each frequency are considered. When these results are combined with previous observations, referring to frequencies outside the considered range, a spectral index of -1.00\pm0.01 is found in the range \sim0.05-300 MHz, compatible with the presence of radio-wave scattering between 1 and 100 R_{Sun}.

We present observations and analysis of an X1.8 non-eruptive solar flare on 2012 October 23, which is characterized by an extremely large late-phase peak seen in the warm coronal extreme-ultraviolet (EUV) emissions (\sim 3 MK), with the peak intensity over 1.4 times that of main flare peak. The flare is driven by a failed eruption of a magnetic flux rope (MFR), whose strong squeeze force acting on the overlying magnetic structures gives rise to an intense early heating of the late-phase loops. Based on differential emission measure (DEM) analysis, it is found that the late-phase loops experience a "longer-than-expected" cooling without the presence of any obvious additional heating, and meanwhile, their volume emission measure (EM) maintains a plateau level for a long time before turning into an evident decay. Without the need for an additional heating, we propose that the special thermodynamic evolution of the late-phase loops revealed in this flare might arise from loop cross-sectional expansions with height, which are evidenced by both direct measurements from EUV images and by magnetic field extrapolation. By blocking the losses of both heat flux and mass from the corona, such an upward cross-sectional expansion not only elongates the loop cooling time, but also more effectively sustains the loop density, therefore leading to a later-than-expected occurrence of the warm coronal late phase in combination with a sufficiently high late-phase peak. We further verify such a scenario by analytically solving the cooling process of a late-phase loop characterized by a variable cross section.

We present the discovery of an extended and faint tail observed in the isolated environment associated with galaxy NGC 3785. This study additionally provides observational evidence supporting the formation of ultra-diffuse galaxies at the end of the tail. We utilized the Gnuastro software to detect and analyse the low surface brightness structures in the optical g, and r bands using data from the Dark Energy Camera Legacy Survey. We created a detection map to identify the faint tail, and measured its length using cubic spline fitting. Additionally, we found 84 star-forming clumps along the tail and performed photometric analysis on the tail portion after applying a significance threshold on the signal-to-noise ratio. We have measured the projected length of the tail, which is \sim390 kpc. We propose that this tail arises from the interaction of the NGC 3785 with a gas-rich galaxy, which ends up as ultra-diffuse galaxy at the end of the tail.

The study of massive binary systems has steadily progressed over the past decades, with increasing focus on their evolution, interactions and mergers, driven by improvements in computational modelling and observational techniques. In particular, when a binary system involves a massive giant and a neutron star (NS) or a black hole (BH) that go through common envelope evolution (CEE), it might results in the merger of the compact object with the core of its giant companion, giving rise to various high energy astrophysical phenomena. We review the different evolutionary channels that lead to compact objects-core mergers, key physical processes with emphasis on the role of accretion physics, feasibility of r-process nucleosynthesis, expected observable electromagnetic, neutrinos and gravitational-waves (GWs) signatures, as well as potential correlation with detected core collapse supernovae (CCSNe), luminous fast blue optical transients (LFBOTs) and low luminosity long gamma-ray bursts (LGRBs). After presenting our current understanding of these mergers, we conclude discussing prospects for future advancements.

Vera Delfavero, K. E. Saavik Ford, Barry McKernan, Harrison E. Cook, Kaila Nathaniel, Jake Postiglione, Shawn Ray, Richard O'Shaughnessy

The Active Galactic Nuclei (AGN) channel for the formation of binary black hole (BBH) mergers has been previously studied as a potential formation channel for the merging compact binaries observed by the LIGO/Virgo/KAGRA (LVK) scientific collaboration. The first two papers in this series explored the McFACTS code for the evolution of black hole orbits in AGN accretion disks for individual galaxy models and described the characteristics of predicted BBH populations in realizations of those models (such as the correlation between mass ratio and aligned spin). In this work, we explore the impact of the properties of AGN host galaxies and assume an AGN lifetime and cosmological model for the density of AGN in a universe like our own. By sampling from an inferred population of AGN, we marginalize over galaxy mass to predict a population of BBH mergers observable by modern ground-based gravitational wave observatories. We find that for reasonable assumptions, AGN disk environments may account for massive BBH mergers such as GW190521 and GW190929_012149. We find that the majority of observable BBH mergers from our simulation are expected to originate in galaxies with a super-massive black hole between 10^{7}M_{\odot} and 10^{9.4}M_{\odot}. We also find that if hierarchical mergers from AGN disks account for a substantial part of the LVK population, our current models require an AGN lifetime of 0.5 to 2.5 Myr.

The study of the X-ray emission from massive binaries constitutes a relevant approach to investigate shock physics. The case of short period binaries may turn out to be quite challenging, especially in very asymmetric systems where the primary wind may overwhelm that of the secondary in the wind interaction. Our objective consists in providing an observational diagnostic of the X-ray behaviour of HD93205, that is a very good candidate to investigate these aspects. We analysed 31 epochs of XMM-Newton X-ray data spanning about two decades to investigate its spectral and timing behaviour. The X-ray spectrum is very soft along the full orbit, with a luminosity exclusively from the wind interaction region in the range of 2.3 -- 5.4\,\times10^{32}\,erg\,s^{-1}. The light curve peaks close to periastron, with a rather wide pre-periastron low-state coincident with the secondary's body hiding a part of the X-ray emitting region close to its surface. We determined a variability time scale of 6.0807\,\pm\,0.0013\,d, in full agreement with the orbital period. Making use of a one-dimensional approach to deal with mutual radiative effects, our results point to a very likely hybrid wind interaction, with a wind-photosphere occurring along most of the orbit, while a brief episode of wind-wind interaction may still develop close to apastron. Beside mutual radiative effects, the radiative nature of the shock that leads to some additional pre-shock obliquitity of the primary wind flow certainly explains the very soft emission. HD93205 constitutes a relevant target to investigate shock physics in short period, asymmetric massive binary systems, where various mutual radiative effects and radiative shocks concur to display an instructive soft X-ray behaviour. HD93205 should be considered as a valid, though challenging target for future three-dimensional modelling initiatives.

Alina A. Volnova, Patrick D. Aleo, Anastasia Lavrukhina, Etienne Russeil, Timofey Semenikhin, Emmanuel Gangler, Emille E. O. Ishida, Matwey V. Kornilov, Vladimir Korolev, Konstantin Malanchev, Maria V. Pruzhinskaya, Sreevarsha Sreejith

SNAD is an international project with a primary focus on detecting astronomical anomalies within large-scale surveys, using active learning and other machine learning algorithms. The work carried out by SNAD not only contributes to the discovery and classification of various astronomical phenomena but also enhances our understanding and implementation of machine learning techniques within the field of astrophysics. This paper provides a review of the SNAD project and summarizes the advancements and achievements made by the team over several years.

We perform a Bayesian analysis of anisotropy in binary galaxy spin directions in the Hyper-Suprime Cam Data Release 3 catalogue, in response to a recent claim that it exhibits a dipole Shamir 2024. We find no significant evidence for anisotropy, or for a direction-independent spin probability that differs from 0.5. These results are unchanged allowing for a quadrupole or simply searching for a fixed anisotropy between any two hemispheres, and the Bayes factor indicates decisive evidence for the isotropic model. Our principled method contrasts with the ad-hoc statistic employed by Shamir 2024. Our code is publicly available.

The Square Kilometer Array will initiate a new era of radio astronomy by allowing 3D imaging of the Universe during Cosmic Dawn and Reionization. Modern machine learning is crucial to analyse the highly structured and complex signal. However, accurate training data is expensive to simulate, and supervised learning may not generalize. We introduce a self-supervised vision transformer, SKATR, whose learned encoding can be cheaply adapted for downstream tasks on 21cm maps. Focusing on regression and generative inference of astrophysical and cosmological parameters, we demonstrate that SKATR representations are maximally informative and that SKATR generalises out-of-domain to differently-simulated, noised, and higher-resolution datasets.

Congcong Zhang, Joelene Hales, Els Peeters, Jan Cami, Ameek Sidhu, Junfeng Zhen

Polycyclic aromatic hydrocarbons (PAHs) are responsible for strong mid-IR emission features near star-forming regions. It is well known that low-metallicity environments exhibit weaker PAH emission, but it is not clear how the metallicity affects the properties of the emitting PAH population. We present a detailed study of the PAH emission in the low-metallicity regime represented by 30 Dor in the Large Magellanic Cloud (LMC) and we compare it to the PAH emission in the Orion Bar to investigate the characteristics of the PAH population and how the environments affects the resulting IR emission. We analyze JWST observations of 30 Dor that include imaging (NIRCam, MIRI) and spectroscopy (NIRSpec/IFU, MIRI/MRS). We extracted NIRSpec/IFU and MIRI/MRS spectra from 18 apertures that cover the morphological structures of 30 Dor. We characterize the profiles and relative intensities of PAH emission in these apertures. The detailed profiles of the PAH emission bands in 30 Dor are all very similar, and compare well to those from one of the dissociation fronts (DF2) in the Orion Bar. The relative band ratios on the other hand show a much larger range than in the Orion Bar. The PAH emission in 30 Dor originates from a population with a higher ionization fraction than in the Orion Bar, and a size distribution that has more smaller PAHs. Since smaller PAHs typically photo-fragment before larger PAHs, our findings support the hypothesis that the lower PAH emission for lower metallicities is the result of inhibition of growth toward larger PAHs rather than photo-fragmentation.

Belinda Damian, Jessy Jose, Swagat R. Das, Saumya Gupta, Vignesh Vaikundaraman, D. K. Ojha, Sreeja S. Kartha, Neelam Panwar, Chakali Eswaraiah

Young star-forming regions in massive environments are ideal test beds to study the influence of surroundings on the evolution of disks around low-mass stars. We explore two distant young clusters, IC 1848-East and West located in the massive W5 complex. These clusters are unique due to their similar (distance, age, and extinction) yet distinct (stellar density and FUV radiation fields) physical properties. We use deep multi-band photometry in optical, near-IR, and mid-IR wavelengths complete down to the substellar limit in at least five bands. We trace the spectral energy distribution of the sources to identify the young pre-main sequence members in the region and derive their physical parameters. The disk fraction for the East and West clusters down to 0.1 M_\odot was found to be \sim27\pm2% (N_{disk}=184, N_{diskless}=492) and \sim17\pm1% (N_{disk}=173, N_{diskless}=814), respectively. While no spatial variation in the disk fraction is observed, these values are lower than those in other nearby young clusters. Investigating the cause of this decrease, we find a correlation with the intense feedback from massive stars throughout the cluster area. We also identified the disk sources undergoing accretion and observed the mass accretion rates to exhibit a positive linear relationship with the stellar host mass and an inverse relationship with stellar age. Our findings suggest that the environment significantly influences the dissipation of disks in both clusters. These distant clusters, characterized by their unique attributes, can serve as templates for future studies in outer galaxy regions, offering insights into the influence of feedback mechanisms on star and planetary formation.

C. Gieser, J. E. Pineda, D. M. Segura-Cox, P. Caselli, M. T. Valdivia-Mena, M. J. Maureira, T. H. Hsieh, L. A. Busch, L. Bouscasse, A. Lopez-Sepulcre, R. Neri, M. Kuffmeier, Th. Henning, D. Semenov, N. Cunningham, I. Jimenez-Serra

Context. The formation of stars has been subject to extensive studies in the past decades from molecular cloud to protoplanetary disk scales. It is still not fully understood how the surrounding material in a protostellar system, that often shows asymmetric structures with complex kinematic properties, feeds the central protostar(s) and their disk(s). Aims. We study the spatial morphology and kinematic properties of the molecular gas surrounding the IRS3A and IRS3B protostellar systems in the L1448N region located in the Perseus molecular cloud. Methods. We present 1 mm NOEMA observations of the PRODIGE large program and analyze the kinematic properties of molecular lines. Given the complexity of the spectral profiles, the lines are fitted with up to three Gaussian velocity components. The clustering algorithm DBSCAN is used to disentangle the velocity components into the underlying physical structure. Results. We discover an extended gas bridge (~3000 au) surrounding both the IRS3A and IRS3B systems in six molecular line tracers (C18O, SO, DCN, H2CO, HC3N, and CH3OH). This gas bridge is oriented along the northeast-southwest direction and shows clear velocity gradients on the order of 100 km/s/pc towards the IRS3A system. We find that the observed velocity profile is consistent with analytical streamline models of gravitational infall towards IRS3A. The high-velocity C18O (2-1) emission towards IRS3A indicates a protostellar mass of ~1.2 Msun. Conclusions. While high angular resolution continuum data often show IRS3A and IRS3B in isolation, molecular gas observations reveal that these systems are still embedded within a large-scale mass reservoir with a complex spatial morphology as well as velocity profiles. The kinematic properties of the extended gas bridge are consistent with gravitational infall toward the IRS3A protostar.

This chapter provides an overview of the basic concepts foundational to atmospheric physics and chemistry. We discuss the retention of atmospheres against thermal evaporation and the global energy balance of planets. We present simple derivations of the vertical profile of an atmosphere, which may be shaped by convective and radiative transport. We then briefly touch upon the three-dimensional atmospheric structure, as shaped by circulation patterns. We describe how the abundances of chemical species in the atmosphere are determined, starting with the assumption of chemical equilibrium and then expanding to various disequilibrium effects. We introduce the particles that can be important components of atmospheres (clouds and hazes) and sketch out some of their complexity. Finally, we review some of the differences between atmospheres of terrestrial and gaseous worlds.

Very little is known about the cosmological history from after the end of inflation until Big Bang Nucleosynthesis. Various well-motivated models predict that the universe could have undergone a period of matter domination in this early epoch. We demonstrate that if the particles causing matter domination have self-interactions, they can form halos that undergo a gravothermal collapse. This scenario, in principle, provides a novel way to produce primordial black holes within the mass range of 1 to 10^{26} g. We also find that it is not only black holes that can form in the aftermath of a gravothermal evolution. In particular, we show that number-changing annihilations of the particles can create sufficient heat to halt the gravothermal evolution, thus forming a "cannibal star". Likewise, the pressure from the particle's repulsive self-interactions can form a boson star during a gravothermal evolution. Thus, our study highlights that structure formation in the early universe can have a rich complexity.

Recent studies of high-redshift galaxies using JWST, such as GN-z11 revealed highly elevated levels of nitrogen (N). This phenomenon extends to gravitationally-lensed galaxies like the Sunburst Arc at z = 2.37, as well as to globular clusters (GCs). We propose that this originates from the presence of very massive stars (VMSs) with masses ranging from 100 to 1000\,\Msun. The He {\sc ii} observed in the Sunburst Arc could also stem from the disproportionately large contribution of VMSs. We build an entirely new Framework for massive star evolution which is no longer set by Dutch or other mass-loss "recipes" but which take the physics of \Gamma or L/M-dependent winds into account. We discuss the mass-loss kink and the transition mass-loss rate between optically thin and thick winds, before we study the evaporative mass-loss history of VMSs. Our novel evolution models exhibit vertical evolution in the HR-diagram from the zero-age main sequence due to a self-regulatory effect driven by their wind-dominated nature, and we discuss what wind physics sets the stellar upper-mass limit. Our estimate for the Sunburst Arc in Vink (2023) suggests that the significant amounts of N found in star-forming galaxies likely arise from VMSs. We evaluate the strengths and weaknesses of previous hypotheses, including fast rotating massive stars and supermassive stars (SMSs), and we conclude that only our VMS model satisfies the relevant criteria. Finally, we advocate for the inclusion of VMSs in population synthesis and chemical evolution models, emphasizing the need for a self-consistent wind approach, which currently does not exist. Even minor inaccuracies in mass-loss rates dramatically impact the stellar evolution of VMS, as well as their ionizing and chemical feedback.