Sazuna/UAT_keywords huggingface dataset:
Reverberation Mapping of High-mass and High-redshift Quasars Using Gravitational Time Delays. Mass estimates of black holes (BHs) in the centers of active galactic nuclei (AGNs) often rely on the radius–luminosity relation. However, this relation, usually probed by reverberation mapping (RM), is poorly constrained in the high-luminosity and high-redshift ends due to the very long expected RM lag times. Multiply imaged AGNs may offer a unique opportunity to explore the radius–luminosity relation at these ends. In addition to comprising several magnified images enabling a more efficient light-curve sampling, the time delay between multiple images of strongly lensed quasars can also aid in making such RM measurements feasible on reasonable timescales: if the strong-lensing time delay is, for example, of the order of the expected RM time lag, changes in the emission lines in the leading image can be observed around the same time as the changes in the continuum in the trailing image. In this work we probe the typical time-delay distribution in galaxy-cluster lenses and estimate the number of both high-mass (∼109‑1010 M ⊙) and high-redshift (z ≳ 4‑12) quasars that are expected to be strongly lensed by clusters. We find that up to several tens of thousands of M BH ∼ 106–108 M ⊙ broad-line AGNs at z &gt; 4 should be multiply imaged by galaxy clusters and detectable with JWST, hundreds with Euclid, and several thousand with the Roman Space Telescope, across the whole sky. These could supply an important calibration for the BH mass scaling in the early Universe.

Keywords: Galaxy clusters, Strong gravitational lensing, Active galactic nuclei, Quasars
Quijote-PNG: Optimizing the Summary Statistics to Measure Primordial Non-Gaussianity. We apply a suite of different estimators to the QUIJOTE-PNG halo catalogs to find the best approach to constrain Primordial non-Gaussianity (PNG) at nonlinear cosmological scales, up to  kmax=0.5hMpc‑1 . The set of summary statistics considered in our analysis includes the power spectrum, bispectrum, halo mass function, marked power spectrum, and marked modal bispectrum. Marked statistics are used here for the first time in the context of the PNG study. We perform a Fisher analysis to estimate their cosmological information content, showing substantial improvements when marked observables are added to the analysis. Starting from these summaries, we train deep neural networks to perform likelihood-free inference of cosmological and PNG parameters. We assess the performance of different subsets of summary statistics; in the case of  fNLequil , we find that a combination of the power spectrum and a suitable marked power spectrum outperforms the combination of power spectrum and bispectrum, the baseline statistics usually employed in PNG analysis. A minimal pipeline to analyze the statistics we identified can be implemented either with our ML algorithm or via more traditional estimators, if these are deemed more reliable.

Keywords: Non-Gaussianity, N-body simulations, Cosmological parameters from large-scale structure
The Next Step in Galaxy Cluster Strong Lensing: Modeling the Surface Brightness of Multiply Imaged Sources. Overcoming both modeling and computational challenges, we present, for the first time, the extended surface-brightness distribution model of a strongly lensed source in a complex galaxy-cluster-scale system. We exploit the high-resolution Hubble Space Telescope (HST) imaging and extensive Multi Unit Spectroscopic Explorer spectroscopy to build an extended strong-lensing model, in a full multiplane formalism, of SDSS J1029+2623, a lens cluster at z = 0.588 with three multiple images of a background quasar (z = 2.1992). Going beyond typical cluster strong-lensing modeling techniques, we include as observables both the positions of 26 pointlike multiple images from seven background sources, spanning a wide redshift range between 1.02 and 5.06, and the extended surface-brightness distribution of the strongly lensed quasar host galaxy, over ∼78,000 HST pixels. In addition, we model the light distribution of seven objects, angularly close to the strongly lensed quasar host, over ∼9300 HST pixels. Our extended lens model reproduces well both the observed intensity and morphology of the quasar host galaxy in the HST F160W band (with a 0.″03 pixel scale). The reconstructed source shows a single, compact, and smooth surface-brightness distribution, for which we estimate an intrinsic magnitude of 23.3 ± 0.1 in the F160W band and a half-light radius of (2.39 ± 0.03) kpc. The increased number of observables enables the accurate determination of the total mass of line-of-sight halos lying angularly close to the extended arc. This work paves the way for a new generation of galaxy cluster strong-lens models, where additional, complementary lensing observables are directly incorporated as model constraints. *This work is based in large part on data collected at the ESO Very Large Telescope (prog. ID 0102.A-0642(A)) and NASA Hubble Space Telescope.

Keywords: Galaxy clusters, Strong gravitational lensing, Dark matter, Quasars
The Importance of Ambipolar Heating in the Standard Thin Accretion Disk with Outflows. This study examines the importance of the thermal effects of ambipolar diffusion (AD), by analyzing the governing properties in the middle and outer regions of a standard thin accretion disk with outflows. To accomplish this, we derive the nonideal magnetohydrodynamic equations, considering both the dynamical and thermal impacts of AD in these regions of the disk. In a stationary state, we utilize the self-similar technique to analyze the vertical structure of a disk with outflows and express the ambipolar diffusivity in terms of the Alfvén velocity and the Elsässer number. Our main focus is on the vertical temperature profile at large radii of the disk when the values of the Elsässer number are small. While the findings indicate that AD heating has minimal effects within the disk, it does play a critical role near the disk surface. When the Elsässer number is low, there is a notable rate of outflows and disk evaporation, resulting in angular momentum transport in these regions. This issue becomes important when we decrease the value of turbulent viscosity, as it leads to highlighting the AD heating effect. This allows the surface regions to become hotter and results in an increase in the drive of the outflows. The results of this research may be important for studying disk coronae and disk dispersal in the middle and outer regions of the thin accretion disk.

Keywords: Magnetic fields, Stellar accretion
Luminosity Evolution of the Hot Gas in Normal Galaxies from the Near Universe to z = 0.5. We explore the evolution of the ∼107 K hot gas in normal galaxies out to redshift = 0.5 (lookback time = 5 Gyr), using X-ray luminosity functions (XLFs) built from a sample of 575 normal galaxies with z &lt; 0.6 detected in five high-galactic-latitude Chandra wide-field surveys. After estimating the emission due to the hot gas component (reducing the sample to ∼400 galaxies), we compared the XLF in three redshift bins (z = 0.1, 0.3, and 0.5), finding increases in the number of galaxies per unit comoving volume from z = 0.1 to 0.3 and then from z = 0.3 to 0.5. These XLF changes suggest a significant (∼5σ) X-ray luminosity evolution of the hot gas, with L X,GAS decreasing by a factor of 6–10 in the last 5 Gyr (from z = 0.5 to 0.1). The relative abundance of L X,GAS ∼ 1041 erg s‑1 galaxies at higher z suggests that high-z, moderate-L X,GAS galaxies may be the optimal target to solve the missing baryon problem. In early-type galaxies, this observational trend is qualitatively consistent with (but larger than) the expected time-dependent mass-loss rate in cooling flow models without active galactic nucleus feedback. In late-type galaxies, the observational trend is also qualitatively consistent with (but larger than) the effect of the z-dependent star formation rate.

Keywords: X-ray astronomy, X-ray surveys, X-ray sources, Galaxy evolution, Galaxies
The Effect of Anisotropic Energy Injection on the Ejecta Emission. A rapidly rotating magnetar has long been assumed to inject energy into the ejecta through isotropic output energy in previous works. However, the output energy of a magnetar is anisotropic and a jet is generally presented in the rotational direction of a magnetar. In this paper, we present a consistent model of the energy injection from a magnetar, considering both the anisotropic magnetic dipole radiation and the jet's ingredient (i.e., the late jet mentioned refers to the beamed magnetars wind). In the situation that the energy injection into the ejecta presents a significant effect on the ejecta's emission, two facts are obtained. (1) For an observer in the equatorial direction, there is no significant difference between the light curves of the ejecta's emission based on the consistent model and those obtained in previous works (i.e., based on the isotropic energy injection). (2) For an on jet-axis observer, however, the difference is significant, especially in the optical/U-band. If the jet is not present in the system, the rise of the optical/U-band light-curve is actually steeper than that in previous works because the output energy of the anisotropic magnetic dipole radiation is mainly in the equatorial direction. If the jet is present in the system, a bump from the cocoon (i.e., the late jet launch is expected to shock and heat-up the ejecta) may only appear in the optical/U-band light curve for a quasi-isotropic ejecta. Our results reveal that the anisotropic energy output of the magnetic dipole radiation and the jet's ingredient should be well considered in modeling the ejecta emission by considering the energy injection from a magnetar. In addition, the optical/U-band light-curve may disclose the central engine of the burst.

Keywords: Gamma-ray bursts
Measurements of the Reaction Rate Coefficients of Atomic Hydrogen with Astrochemical Anions: CN<SUP>‑</SUP> and C<SUB>3</SUB>N<SUP>‑</SUP>. We present the temperature-dependent reaction rate coefficients of CN‑ and C3N‑ with atomic hydrogen in the temperature range from 7 to 290 K, measured in a 16-pole radio-frequency ion trap. The rate of C3N‑ with H steadily increases toward lower temperatures, while the rate coefficients for the CN‑ + H system show a sudden change around 160 K. Fits to the data were performed to determine temperature-dependent reaction rate coefficients. The fits reveal a rate coefficient of  4.1(3)×10‑10(T/300)‑0.31(6)  cm3 s‑1 for C3N‑ + H. For CN‑, we determined a rate coefficient for the temperature regime below 160 K of  3.2(4)×10‑10(T/300)‑0.31(11)  cm3 s‑1. Given our present results, higher rate coefficients than previously reported must be assumed for the modeling of cold interstellar environments involving these H atom reactions.

Keywords: Ion-neutral reactions, Laboratory astrophysics, Interstellar clouds
A Broadband X-Ray Investigation of Fast-spinning Intermediate Polar CTCV J2056─3014. We report on XMM-Newton, NuSTAR, and NICER X-ray observations of CTCV J2056─3014, a cataclysmic variable (CV) with one of the fastest-spinning white dwarfs (WDs) at P = 29.6 s. While previously classified as an intermediate polar, CJ2056 also exhibits the properties of WZ Sge─type CVs, such as dwarf novae and superoutbursts. With XMM-Newton and NICER, we detected the spin period up to ∼2 keV with 7σ significance. We constrained its derivative to  |Ṗ|&lt;1.8×10−12  s s−1 after correcting for binary orbital motion. The pulse profile is characterized by a single broad peak with ∼25% modulation. NuSTAR detected a fourfold increase in unabsorbed X-ray flux coincident with an optical flare, in 2022 November. The XMM-Newton and NICER X-ray spectra at 0.310 keV are best characterized by an absorbed, optically thin three-temperature thermal plasma model (kT = 0.3, 1.0, and 4.9 keV), while the NuSTAR spectra at 3─30 keV are best fit by a single-temperature thermal plasma model (kT = 8.4 keV), both with Fe abundance Z Fe/Z ⊙ = 0.3. CJ2056 exhibits similarities to other fast-spinning CVs, such as low plasma temperatures and no significant X-ray absorption at low energies. As the WD's magnetic field strength is unknown, we applied both nonmagnetic and magnetic CV spectral models (MKCFLOW and MCVSPEC) to determine the WD mass. The derived WD mass range (M = 0.7─1.0 M ⊙) is above the centrifugal breakup mass limit of 0.56 M ⊙ and consistent with the mean WD mass of local CVs (M ≍ 0.8─0.9 M ⊙).

Keywords: White dwarf stars, DQ Herculis stars, X-ray observatories, Compact objects, Cataclysmic variable stars
Spectrophotometric Reverberation Mapping of Intermediate-mass Black Hole NGC 4395. Understanding the origins of massive black hole seeds and their coevolution with their host galaxy requires studying intermediate-mass black holes (IMBHs) and estimating their mass. However, measuring the masses of these IMBHs is challenging, due to the high-spatial-resolution requirement. Spectrophotometric reverberation monitoring is performed for a low-luminosity Seyfert 1 galaxy, NGC 4395, to measure the size of the broad-line region and black hole mass. The data were collected using the 1.3 m Devasthal fast optical telescope and 3.6 m Devasthal optical telescope at ARIES, Nainital, over two consecutive days in 2022 March. The analysis revealed strong emission lines in the spectra and light curves of the merged 5100 Å spectroscopic continuum flux (f 5100) with the photometric continuum V band and Hα, with fractional variabilities of 6.38% and 6.31% respectively. In comparison to several previous studies with lag estimation &lt;90 minutes, our calculated Hα lag supersedes them by  125.0‑6.1+6.2  minutes, using the ICCF and JAVELIN methods. The velocity dispersion (σ line) of the broad-line clouds is measured to be  544.7‑25.1+22.4  km s‑1, yielding a black hole mass of ∼ 2.2‑0.2+0.2×104M⊙  and an Eddington ratio of 0.06.

Keywords: Intermediate-mass black holes, Black holes, Reverberation mapping, Active galactic nuclei, Spectroscopy
The SAGA Survey. III. A Census of 101 Satellite Systems around Milky Way─mass Galaxies. We present Data Release 3 (DR3) of the Satellites Around Galactic Analogs (SAGA) Survey, a spectroscopic survey characterizing satellite galaxies around Milky Way (MW)-mass galaxies. The SAGA Survey DR3 includes 378 satellites identified across 101 MW-mass systems in the distance range of 25─40.75 Mpc, and an accompanying redshift catalog of background galaxies (including about 46,000 taken by SAGA) in the SAGA footprint of 84.7 deg2. The number of confirmed satellites per system ranges from zero to 13, in the stellar mass range of 106−10 M ⊙. Based on a detailed completeness model, this sample accounts for 94% of the true satellite population down to M ⋆ = 107.5 M ⊙. We find that the mass of the most massive satellite in SAGA systems is the strongest predictor of satellite abundance; one-third of the SAGA systems contain LMC-mass satellites, and they tend to have more satellites than the MW. The SAGA satellite radial distribution is less concentrated than the MW's, and the SAGA quenched fraction below 108.5 M ⊙ is lower than the MW's, but in both cases, the MW is within 1σ of SAGA system-to-system scatter. SAGA satellites do not exhibit a clear corotating signal as has been suggested in the MW/M31 satellite systems. Although the MW differs in many respects from the typical SAGA system, these differences can be reconciled if the MW is an older, slightly less massive host with a recently accreted LMC/SMC system.

Keywords: Companion galaxies, Dwarf galaxies, Galaxy evolution, Galaxy spectroscopy, Redshift surveys
The SAGA Survey. IV. The Star Formation Properties of 101 Satellite Systems around Milky Way–mass Galaxies. We present the star-forming properties of 378 satellite galaxies around 101 Milky Way analogs in the Satellites Around Galactic Analogs (SAGA) Survey, focusing on the environmental processes that suppress or quench star formation. In the SAGA stellar mass range of 106‑10 M ⊙, we present quenched fractions, star-forming rates, gas-phase metallicities, and gas content. The fraction of SAGA satellites that are quenched increases with decreasing stellar mass and shows significant system-to-system scatter. SAGA satellite quenched fractions are highest in the central 100 kpc of their hosts and decline out to the virial radius. Splitting by specific star formation rate (sSFR), the least star-forming satellite quartile follows the radial trend of the quenched population. The median sSFR of star-forming satellites increases with decreasing stellar mass and is roughly constant with projected radius. Star-forming SAGA satellites are consistent with the star formation rate–stellar mass relationship determined in the Local Volume, while the median gas-phase metallicity is higher and median H I gas mass is lower at all stellar masses. We investigate the dependence of the satellite quenched fraction on host properties. Quenched fractions are higher in systems with larger host halo mass, but this trend is only seen in the inner 100 kpc; we do not see significant trends with host color or star formation rate. Our results suggest that lower-mass satellites and satellites inside 100 kpc are more efficiently quenched in a Milky Way–like environment, with these processes acting sufficiently slowly to preserve a population of star-forming satellites at all stellar masses and projected radii.

Keywords: Galaxy quenching
The SAGA Survey. V. Modeling Satellite Systems around Milky Way─Mass Galaxies with Updated UNIVERSEMACHINE. Environment plays a critical role in shaping the assembly of low-mass galaxies. Here, we use the UNIVERSEMACHINE (UM) galaxy─halo connection framework and Data Release 3 of the Satellites Around Galactic Analogs (SAGA) Survey to place dwarf galaxy star formation and quenching into a cosmological context. UM is a data-driven forward model that flexibly parameterizes galaxy star formation rates (SFRs) using only halo mass and assembly history. We add a new quenching model to UM, tailored for galaxies with m ⋆ ≲ 109 M ⊙, and constrain the model down to m ⋆ ≳ 107 M ⊙ using new SAGA observations of 101 satellite systems around Milky Way (MW)─mass hosts and a sample of isolated field galaxies in a similar mass range from the Sloan Digital Sky Survey. The new best-fit model, "UM-SAGA," reproduces the satellite stellar mass functions, average SFRs, and quenched fractions in SAGA satellites while keeping isolated dwarfs mostly star-forming. The enhanced quenching in satellites relative to isolated field galaxies leads the model to maximally rely on halo assembly to explain the observed environmental quenching. Extrapolating the model down to m ⋆ ∼ 106.5 M ⊙ yields a quenched fraction of ≳30% for isolated field galaxies and ≳80% for satellites of MW-mass hosts at this stellar mass. Spectroscopic surveys can soon test this specific prediction to reveal the relative importance of internal feedback, cessation of mass and gas accretion, satellite-specific gas processes, and reionization for the evolution of faint low-mass galaxies.

Keywords: Galaxy dark matter halos, Galaxy formation, Dwarf galaxies, Galaxy quenching, N-body simulations
Radio Morphology of Gamma-Ray Sources: Double-lobed Radio Sources. The extragalactic γ-ray sky is dominated by relativistic jets aligned to the observer's line of sight, i.e., blazars. A few of their misaligned counterparts, e.g., radio galaxies, are also detected with the Fermi-Large Area Telescope (LAT), albeit in a small number (∼50), indicating the crucial role played by the jet viewing angle in detecting γ-ray emission from jets. These γ-ray emitting misaligned active galactic nuclei (AGN) provide us with a unique opportunity to understand the high-energy emission production mechanisms from a different viewpoint than the more common blazars. With this goal in mind, we have systematically studied the radio morphology of γ-ray emitting sources present in the fourth data release of the fourth catalog of Fermi-LAT detected γ-ray sources to identify misaligned AGN. By utilizing the high-resolution and sensitive MHz and GHz frequency observations delivered by the Very Large Array Sky Survey, Low-Frequency Array Two-metre Sky Survey, Faint Images of the Radio Sky at Twenty Centimeters, and Rapid ASKAP Continuum Survey, here we present a catalog of 149 γ-ray detected misaligned AGN, thus approximately tripling the number of known objects of this class. Our sample includes a variety of radio morphologies, e.g., edge-darkened and edge-brightened, hybrids, wide-angle-tailed, bent jets, and giants. Since the γ-ray emission is thought to be highly sensitive to the jet viewing angle, such an enlarged sample of γ-ray detected misaligned radio sources will permit us to explore the origin of high-energy emission in relativistic jets and radio lobes and study AGN unification, in general.

Keywords: BL Lacertae objects, Radio jets, Relativistic jets, Fanaroff-Riley radio galaxies, Gamma-ray astronomy
Physical Models for the Astrophysical Population of Black Holes: Application to the Bump in the Mass Distribution of Gravitational-wave Sources. Gravitational-wave observations of binary black holes have revealed unexpected structure in the black hole mass distribution. Previous studies employ physically motivated phenomenological models and infer the parameters that control the features of the mass distribution that are allowed in their model, associating the constraints on those parameters with their physical motivations a posteriori. In this work, we take an alternative approach in which we introduce a model parameterizing the underlying stellar and core-collapse physics and obtaining the remnant black hole distribution as a derived by-product. In doing so, we constrain the stellar physics necessary to explain the astrophysical distribution of black hole properties under a given model. We apply this to the mapping between initial mass and remnant black hole mass, accounting for mass-dependent mass loss using a simple parameterized description. Allowing the parameters of the initial mass–remnant mass relationship to evolve with redshift permits correlated and physically reasonable changes to features in the mass function. We find that the current data are consistent with no redshift evolution in the core–remnant mass relationship, but place only weak constraints on the change of these parameters. This procedure can be applied to modeling any physical process underlying the astrophysical distribution. We illustrate this by applying our model to the pulsational pair instability supernova (PPISN) process, previously proposed as an explanation for the observed excess of black holes at ∼35 M ⊙. Placing constraints on the reaction rates necessary to explain the PPISN parameters, we concur with previous results in the literature that the peak observed at ∼35 M ⊙ is unlikely to be a signature from the PPISN process as presently understood.

Keywords: Bayesian statistics, Black holes, Gravitational wave astronomy, Supernova remnants, Gravitational waves