Sazuna/UAT_keywords huggingface dataset:
Morphological Parameters and Associated Uncertainties for 8 Million Galaxies in the Hyper Suprime-Cam Wide Survey. We use the Galaxy Morphology Posterior Estimation Network (GaMPEN) to estimate morphological parameters and associated uncertainties for ~8 million galaxies in the Hyper Suprime-Cam Wide survey with z ≤ 0.75 and m ≤ 23. GaMPEN is a machine-learning framework that estimates Bayesian posteriors for a galaxy's bulge-to-total light ratio (L  B /L  T ), effective radius (R  e ), and flux (F). By first training on simulations of galaxies and then applying transfer learning using real data, we trained GaMPEN with &lt;1% of our data set. This two-step process will be critical for applying machine-learning algorithms to future large imaging surveys, such as the Rubin-Legacy Survey of Space and Time, the Nancy Grace Roman Space Telescope, and Euclid. By comparing our results to those obtained using light profile fitting, we demonstrate that GaMPEN's predicted posterior distributions are well calibrated (≲5% deviation) and accurate. This represents a significant improvement over light profile fitting algorithms, which underestimate uncertainties by as much as ~60%. For an overlapping subsample, we also compare the derived morphological parameters with values in two external catalogs and find that the results agree within the limits of uncertainties predicted by GaMPEN. This step also permits us to define an empirical relationship between the Sérsic index and L  B /L  T  that can be used to convert between these two parameters. The catalog presented here represents a significant improvement in size (~10×), depth (~4 mag), and uncertainty quantification over previous state-of-the-art bulge+disk decomposition catalogs. With this work, we also release GaMPEN's source code and trained models, which can be adapted to other data sets.

Keywords: Neural networks, Convolutional neural networks, Astronomy data analysis, Galaxy classification systems, Extragalactic astronomy, Galaxies
A Large Magnetic Hump in the VLISM Observed by Voyager 1 in 2020-2022. Voyager 1 has been moving through the very local interstellar medium (VLISM) for approximately one solar cycle, from 122.58 au on 2012/DOY 238 (August 25) to 158.5 au on 2023.0. Previously, an abrupt increase ("jump") in the magnetic field strength B and proton density N by a factor of 1.35 and 1.36, respectively, was observed during an interval of ~8 days in 2020.40. After the jump, B continued to increase to a maximum value ~0.56 nT at ~2021.4 and then declined until B returned to the postjump value of 0.5 nT on 2021.85, 1.45 yr after the jump. The magnetic field strength declined briefly from 0.5 nT on 2021.85 to 0.47 nT on 2021.95 and then increased sporadically to 0.52 nT at 2023.0. Thus, the magnetic field strength remained strong for at least 2.6 yr. The magnetic hump and the density hump were a compression wave propagating through the VLISM. The compression wave was generated by a region with large dynamic pressure in the solar wind that propagated through the inner heliosheath and collided with the heliopause. The magnetic field strength continued to remain strong, with slow variations, until the end of our observations at 2023.0. It is suggested that the magnetic hump evolved from the large dynamic pressure, high speeds, and density observed at 1 au between ~2015 and ~2017.

Keywords: Interstellar magnetic fields
The Impact of Beam Variations on Power Spectrum Estimation for 21 cm Cosmology. II. Mitigation of Foreground Systematics for HERA. One key challenge in detecting a 21 cm cosmological signal at z &gt; 6 is to separate the cosmological signal from foreground emission. This can be studied in a power spectrum space where the foreground is confined to low delay (or, equivalently, k ∥) modes, whereas the cosmological signal can spread out to high delay modes. When there is a calibration error, however, the chromaticity of the gain errors propagates to the power spectrum estimate and contaminates the modes for cosmological detection. The Hydrogen Epoch of Reionization Array (HERA) employs a high-precision calibration scheme using redundancy in measurements. In this study, we focus on the gain errors induced by nonredundancies arising from a feed offset relative to HERA's 14 m parabolic dish element and investigate how to mitigate the chromatic gain errors using three different methods: restricting baseline lengths for calibration, smoothing the antenna gains, and applying a temporal filter prior to calibration. With 2 cm/2° perturbations for translation/tilting motions, a level achievable under normal HERA operating conditions, the combination of the baseline cut and temporal filtering indicates that the spurious gain feature due to nonredundancies is significantly reduced, and the power spectrum recovers the clean foreground-free region. We found that the mitigation technique works even for large feed motions, but in order to keep a stable calibration process, the feed positions need to be constrained to 2 cm for translation motions and 2° for tilting offset relative to the dish's vertex.

Keywords: Cosmology, Astronomical instrumentation, Radio interferometers, Reionization, Radio astronomy
Continuum Reverberation Mapping of Mrk 876 over Three Years with Remote Robotic Observatories. Continuum reverberation mapping probes the size scale of the optical continuum-emitting region in active galactic nuclei (AGN). Through 3 yr of multiwavelength photometric monitoring in the optical with robotic observatories, we perform continuum reverberation mapping on Mrk 876. All wave bands show large-amplitude variability and are well correlated. Slow variations in the light curves broaden the cross-correlation function (CCF) significantly, requiring detrending in order to robustly recover interband lags. We measure consistent interband lags using three techniques (CCF, JAVELIN, and PyROA), with a lag of around 13 days from u to z. These lags are longer than the expected radius of 12 days for the self-gravitating radius of the disk. The lags increase with wavelength roughly following λ 4/3, as would be expected from thin disk theory, but the lag normalization is approximately a factor of 3 longer than expected, as has also been observed in other AGN. The lag in the i band shows an excess that we attribute to variable Hα broad-line emission. A flux-flux analysis shows a variable spectrum that follows f  ν  ∝ λ -1/3, as expected for a disk, and an excess in the i band that also points to strong variable Hα emission in that band.

Keywords: Supermassive black holes, Reverberation mapping, Active galactic nuclei
The LSST AGN Data Challenge: Selection Methods. Development of the Rubin Observatory Legacy Survey of Space and Time (LSST) includes a series of Data Challenges (DCs) arranged by various LSST Scientific Collaborations that are taking place during the project's preoperational phase. The AGN Science Collaboration Data Challenge (AGNSC-DC) is a partial prototype of the expected LSST data on active galactic nuclei (AGNs), aimed at validating machine learning approaches for AGN selection and characterization in large surveys like LSST. The AGNSC-DC took place in 2021, focusing on accuracy, robustness, and scalability. The training and the blinded data sets were constructed to mimic the future LSST release catalogs using the data from the Sloan Digital Sky Survey Stripe 82 region and the XMM-Newton Large Scale Structure Survey region. Data features were divided into astrometry, photometry, color, morphology, redshift, and class label with the addition of variability features and images. We present the results of four submitted solutions to DCs using both classical and machine learning methods. We systematically test the performance of supervised models (support vector machine, random forest, extreme gradient boosting, artificial neural network, convolutional neural network) and unsupervised ones (deep embedding clustering) when applied to the problem of classifying/clustering sources as stars, galaxies, or AGNs. We obtained classification accuracy of 97.5% for supervised models and clustering accuracy of 96.0% for unsupervised ones and 95.0% with a classic approach for a blinded data set. We find that variability features significantly improve the accuracy of the trained models, and correlation analysis among different bands enables a fast and inexpensive first-order selection of quasar candidates.

Keywords: Sky surveys, Classification, Neural networks, Quasars, Active galaxies, Convolutional neural networks, Support vector machine, Active galactic nuclei, Clustering, Random Forests, Catalogs
Distributions of the Density and Kinetic Temperature of the Molecular Gas in the Central Region of NGC 613 Using Hierarchical Bayesian Inference. We present position-position-velocity (PPV) cubes of the physical and chemical properties of the molecular medium in the central 1.2 kpc region of the active galaxy NGC 613 at a PPV resolution of 0.″8 × 0.″8 × 10 km s-1 (0.″8 = ~68 pc). We used eight molecular lines (13CO(1-0), C18O(1-0), HCN(1-0), HCO+(1-0), CS(2-1), HCN(4-3), HCO+(4-3), and CS(7-6)) obtained with the Atacama Large Millimeter/submillimeter Array. Non-LTE calculation with hierarchical Bayesian inference was used to construct PPV cubes of the gas kinetic temperature (T kin), molecular hydrogen volume density ( ${n}_{{{\rm{H}}}_{2}}$ ), column densities ( ${N}_{{{\rm{H}}}_{2}}$ ), and fractional abundances of four molecules (12C18O, HCN, HCO+, and CS). The derived ${n}_{{{\rm{H}}}_{2}}$ , ${N}_{{{\rm{H}}}_{2}}$ , and T kin ranged from 103.21-3.85 cm-3, 1020.8-22.1 cm-2, and 102.33-2.64 K, respectively. Our first application of the non-LTE method with the hierarchical Bayesian inference to external galaxies yielded compatible results compared with the previous studies of this galaxy, demonstrating the efficacy of this method for application to other galaxies. We examined the correlation between gas surface density ${{\rm{\Sigma }}}_{{{\rm{H}}}_{2}}$ (converted from ${N}_{{{\rm{H}}}_{2}}$ ) and the star formation rate ΣSFR obtained from the 110 GHz continuum flux map and found two distinct sequences in the ${{\rm{\Sigma }}}_{{{\rm{H}}}_{2}}$ -ΣSFR diagram; the southwestern subregion of the star-forming ring exhibited a ~0.5 dex higher star formation efficiency (SFE; ΣSFR/ ${{\rm{\Sigma }}}_{{{\rm{H}}}_{2}}$ ) than the eastern subregion. However, they exhibited no systematic difference in ${n}_{{{\rm{H}}}_{2}}$ , which is often argued as a driver of SFE variation. We suggest that the deficiency of molecular gas in the southwestern subregion, where no significant gas supply is evident along the offset ridges in the bar, is responsible for the elevated SFE.

Keywords: Starburst galaxies, Giant molecular clouds, Star formation, Active galactic nuclei, Submillimeter astronomy
Simulations of High-redshift [O III] Emitters: Chemical Evolution and Multiline Diagnostics. Recent observations by the James Webb Space Telescope discovered a number of high-redshift galaxies with strong emission lines from doubly ionized oxygen. Combined with Atacama Large Millimeter/submillimeter Array observations of far-infrared lines, multiline diagnostics can be applied to the high-redshift galaxies in order to probe the physical conditions of the interstellar medium. We study the formation and evolution of galaxies using the FirstLight simulation suite, which provides outputs of 62 high-resolution, zoom-in galaxy simulations. We devise a physical model of H II regions and calculate spatially resolved [O III] line emission. We show that massive galaxies with stellar masses of M * &gt; 109 M ⊙ chemically evolve rapidly to z = 9. Young stellar populations in the star-forming galaxies boost the [O III] line emission, rendering the ratio of line luminosity to star formation rate larger than that for low-redshift galaxies, which is consistent with recent observations. Measuring the flux ratios of rest-frame optical and far-infrared lines allows us to estimate the physical conditions such as density and metallicity of the star-forming gas in high-redshift [O III] emitters.

Keywords: Galaxy evolution
On the Tidal Capture of White Dwarfs by Intermediate-mass Black Holes in Dense Stellar Environments. Intermediate-mass black holes (IMBHs) are the missing link between stellar-mass and supermassive black holes, widely believed to reside in at least some dense star clusters, but not yet observed directly. Tidal disruptions of white dwarfs (WDs) are luminous only for black holes less massive than ~105 M ⊙, therefore providing a unique smoking gun that could finally prove the existence of IMBHs beyond any reasonable doubt. Here, we investigate the tidal captures of WDs by IMBHs in dense star clusters, and estimate upper limits to the capture rates of ~1 Myr-1 for galactic nuclei and ~0.01 Myr-1 for globular clusters. Following the capture, the WD inspirals onto the IMBH, producing gravitational waves detectable out to ~100 Mpc by LISA for ~104 M ⊙ IMBHs. The subsequent tidal stripping/disruption of the WD can also release bright X-ray and gamma-ray emission with luminosities of at least ≳1040 erg s-1, detectable by Chandra, Swift, and upcoming telescopes, such as the Einstein Probe.

Keywords: Intermediate-mass black holes, Tidal interaction, White dwarf stars, Star clusters
The Seoul National University AGN Monitoring Project. IV. Hα Reverberation Mapping of Six AGNs and the Hα Size-Luminosity Relation. The broad-line region (BLR) size-luminosity relation has paramount importance for estimating the mass of black holes in active galactic nuclei (AGNs). Traditionally, the size of the Hβ BLR is often estimated from the optical continuum luminosity at 5100 Å, while the size of the Hα BLR and its correlation with the luminosity is much less constrained. As a part of the Seoul National University AGN Monitoring Project, which provides 6 yr photometric and spectroscopic monitoring data, we present our measurements of the Hα lags of high-luminosity AGNs. Combined with the measurements for 42 AGNs from the literature, we derive the size-luminosity relations of the Hα BLR against the broad Hα and 5100 Å continuum luminosities. We find the slope of the relations to be 0.61 ± 0.04 and 0.59 ± 0.04, respectively, which are consistent with the Hβ size-luminosity relation. Moreover, we find a linear relation between the 5100 Å continuum luminosity and the broad Hα luminosity across 7 orders of magnitude. Using these results, we propose a new virial mass estimator based on the Hα broad emission line, finding that the previous mass estimates based on scaling relations in the literature are overestimated by up to 0.7 dex at masses lower than 107 M ⊙.

Keywords: Reverberation mapping, Active galactic nuclei
The Metal-weak Milky Way Stellar Disk Hidden in the Gaia-Sausage-Enceladus Debris: The APOGEE DR17 View. We have for the first time identified the early stellar disk in the Milky Way by using a combination of elemental abundances and kinematics. Using data from APOGEE DR17 and Gaia we select stars in the Mg-Mn-Al-Fe plane with elemental abundances indicative of an accreted origin and find stars with both halo-like and disk-like kinematics. The stars with halo-like kinematics lie along a lower sequence in [Mg/Fe], while the stars with disk-like kinematics lie along a higher sequence. Combined with astroseismic observations, we determine that the stars with halo-like kinematics are old, 9-11 Gyr, and that the more evolved stellar disk is about 1-2 Gyr younger. We show that the in situ fraction of stars on deeply bound orbits is not small, in fact the inner Galaxy likely harbors a genuine in situ population together with an accreted one. In addition, we show that the selection of the Gaia-Sausage-Enceladus in the E n-L z plane is not very robust. In fact, radically different selection criteria give almost identical elemental abundance signatures for the accreted stars.

Keywords: Milky Way formation, Milky Way disk, Milky Way stellar halo, Milky Way evolution, Milky Way Galaxy
Theoretical Systematics in Testing the Cosmological Principle with the Kinematic Quasar Dipole. The Cosmological Principle (CP) is part of the foundation that underpins the standard model of the Universe. In the era of precision cosmology, when stress tests of the standard model are uncovering various tensions and possible anomalies, it is critical to check the viability of this principle. A key test is the consistency between the kinematic dipoles of the cosmic microwave background and of the large-scale matter distribution. Results using radio continuum and quasar samples indicate a rough agreement in the directions of the two dipoles, but a larger than expected amplitude of the matter dipole. The resulting tension with the radiation dipole has been estimated at ~5σ for some cases, suggesting a potential new cosmological tension and a possible violation of the CP. However, the standard formalism for predicting the dipole in the two-dimensional projection of sources overlooks possible evolution effects in the luminosity function. In fact, radial information from the luminosity function is necessary for a correct projection of the three-dimensional source distribution. Using a variety of current models of the quasar luminosity function, we show that neglecting redshift evolution can significantly overestimate the relative velocity amplitude. While the models we investigate are consistent with each other and with current data, the dipole derived from these, which depends on derivatives of the luminosity function, can disagree by more than 3σ. This theoretical systematic bias needs to be resolved before robust conclusions can be made about a new cosmic tension.

Keywords: Cosmology, Luminosity function, Quasars, Large-scale structure of the universe, Cosmological principle
Exploring Stellar Cluster and Feedback-driven Star Formation in the Galactic Mid-infrared Bubble [HKS2019] E70. We present a comprehensive analysis of the Galactic mid-infrared bubble [HKS2019] E70 (E70) by adopting a multiwavelength approach to understand the physical environment and star formation scenario around it. We identified a small (radius ~1.7 pc) stellar cluster inside the E70 bubble, and its distance is estimated as 3.26 ± 0.45 kpc. This cluster is embedded in the molecular cloud and hosts massive stars, as well as young stellar objects (YSOs), suggesting active star formation in the region. The spectral type of the brightest star (M1) of the E70 cluster is estimated as O9V, and a circular ring/shell of gas and dust is found around it. The diffuse radio emission inside this ring/shell, the excess pressure exerted by the massive star M1 at the YSO's core, and the distribution of photodissociation regions, a class I YSO, and two ultracompact H II regions on the rim of this ring/shell clearly suggest positive feedback of the massive star M1 in the region. We also found a low-density shell-like structure in the 12CO(J = 1-0) molecular emission along the perimeter of the E70 bubble. The velocity structure of the 12CO emission suggests that the feedback from the massive star appears to have expelled the molecular material, and the subsequent swept-up material is what appears as the E70 bubble.

Keywords: Initial mass function, Star forming regions, Star formation, Interstellar medium, H II regions
Origin of Low-26Al/27Al Corundum/Hibonite Inclusions in Meteorites. Most meteoritic calcium-rich, aluminum-rich inclusions formed from a reservoir with 26Al/27Al ≈ 5 × 10-5, but some record lower ${({}^{26}\mathrm{Al}/{}^{27}\mathrm{Al})}_{0}$ , demanding they sampled a reservoir without live 26Al. This has been interpreted as evidence for "late injection" of supernova material into our protoplanetary disk. We instead interpret the heterogeneity as chemical, demonstrating that these inclusions are strongly associated with the refractory phases corundum or hibonite. We name them "low-26Al/27Al corundum/hibonite inclusions" (LAACHIs). We present a detailed astrophysical model for LAACHI formation in which they derive their Al from presolar corundum, spinel, or hibonite grains 0.5-2 μm in size with no live 26Al; live 26Al is carried on smaller (&lt;50 nm) presolar chromium spinel grains from recent nearby Wolf-Rayet stars or supernovae. In hot (≈1350-1425 K) regions of the disk, these grains and perovskite grains would be the only survivors. These negatively charged grains would grow to sizes 1-103 μm, even incorporating positively charged perovskite grains, but not the small, negatively charged 26Al-bearing grains. Chemical and isotopic fractionations due to grain charging was a significant process in hot regions of the disk. Our model explains the sizes, compositions, oxygen isotopic signatures, and the large, correlated 48Ca and 50Ti anomalies (if carried by presolar perovskite) of LAACHIs, and especially how they incorporated no 26Al in a solar nebula with uniform, canonical 26Al/27Al. A late injection of supernova material is obviated, although formation of the Sun in a high-mass star-forming region is demanded.

Keywords: Dust physics, Solar system formation, Protoplanetary disks, Meteorites, Supernovae
Anisotropic Ionizing Illumination from an M-type Pre-main-sequence Star, DM Tau. The powerful, high-energy magnetic activities of young stars play important roles in the magnetohydrodynamics in the innermost parts of the protoplanetary disks. In addition, the associated UV and X-ray emission dictates the photochemistry; moreover, the corona activities can affect the atmosphere of a newborn extrasolar planet. How the UV and X-ray photons are generated and how they illuminate the disks are not well understood. Here we report the analyses of the optical and infrared (OIR) photometric monitoring observations and the high angular resolution centimeter-band images of the low-mass (M1-type) pre-main-sequence star DM Tau. We found that the OIR photometric light curves present periodic variations, which suggests that the host young star is rotating in the same direction as the natal disk and is hosting at least one giant cold spot. In addition, we resolved that the ionized gas in the DM Tau disk is localized and its spatial distribution is varying with time. All the present observations can be coherently interpreted, if the giant cold spot is the dominant anisotropic UV and/or X-ray source that illuminates the ambient cone-like region. These results indicate that a detailed theoretical model of the high-energy protostellar emission is essential in understanding the space weather around extrasolar planets and the origin of life.

Keywords: Observational astronomy, Starspots, T Tauri stars, Protoplanetary disks, Stellar accretion disks, Star-planet interactions