Sazuna/UAT_keywords huggingface dataset:
BASS. XXVIII. Near-infrared Data Release 2: High-ionization and Broad Lines in Active Galactic Nuclei. We present the BAT AGN Spectroscopic Survey (BASS) Near-infrared Data Release 2 (DR2), a study of 168 nearby ( , z &lt; 0.6) active galactic nuclei (AGN) from the all-sky Swift Burst Array Telescope X-ray survey observed with the Very Large Telescope (VLT)/X-shooter in the near-infrared (NIR; 0.8─2.4 μm). We find that 49/109 (45%) Seyfert 2 and 35/58 (60%) Seyfert 1 galaxies observed with VLT/X-shooter show at least one NIR high-ionization coronal line (CL; ionization potential χ &gt; 100 eV). Comparing the emission of the [Si VI] λ1.9640 CL with the X-ray emission for the DR2 AGN, we find a significantly tighter correlation, with a lower scatter (0.37 dex) than that for the optical [O III] λ5007 line (0.71 dex). We do not find any correlation between CL emission and the X-ray photon index Γ. We find a clear trend of line blueshifts with increasing ionization potential in several CLs, such as [Si VI] λ1.9640, [Si X] λ1.4300, [S VIII] λ0.9915, and [S IX] λ1.2520, indicating the radial structure of the CL region. Finally, we find a strong underestimation bias in black hole mass measurements of Sy 1.9 using broad Hα due to the presence of significant dust obscuration. In contrast, the broad Paα and Paβ emission lines are in agreement with the M─σ relation. Based on the combined DR1 and DR2 X-shooter sample, the NIR BASS sample now comprises 266 AGN with rest-frame NIR spectroscopic observations, the largest set assembled to date. * Based on observations collected under programs 086.B-0135(A), 089.B-0951(A), 090.A-0830(A), 091.B-0900(B), 093.A-0766(A), 098.A-0635(B), 099.A-0403(B), 0101.A-0765(A), and 0102.A-0433(A) with X-shooter at the Very Large Telescope of the Paranal Observatory in Chile, operated by the European Southern Observatory.

Keywords: Active galactic nuclei
BASS. XXIX. The Near-infrared View of the Broad-line Region (BLR): The Effects of Obscuration in BLR Characterization. Virial black hole (BH) mass (M BH) determination directly involves knowing the broad-line region (BLR) clouds' velocity distribution, their distance from the central supermassive BH (R BLR), and the virial factor (f). Understanding whether biases arise in M BH estimation with increasing obscuration is possible only by studying a large (N &gt; 100) statistical sample of obscuration-unbiased (hard) X-ray-selected active galactic nuclei (AGNs) in the rest-frame near-infrared (0.8–2.5 μm) since it penetrates deeper into the BLR than the optical. We present a detailed analysis of 65 local Burst Alert Telescope (BAT) selected Seyfert galaxies observed with Magellan/FIRE. Adding these to the near-infrared BAT AGN spectroscopic survey database, we study a total of 314 unique near-infrared spectra. While the FWHMs of Hα and near-infrared broad lines (He I, Paβ, Paα) remain unbiased to either BLR extinction or X-ray obscuration, the Hα broad-line luminosity is suppressed when N H ≳ 1021 cm‑2, systematically underestimating M BH by 0.23–0.46 dex. Near-infrared line luminosities should be preferred to Hα until N H &lt; 1022 cm‑2, while at higher obscuration a less-biased R BLR proxy should be adopted. We estimate f for Seyfert 1 and 2 using two obscuration-unbiased M BH measurements, i.e., the stellar velocity dispersion and a BH mass prescription based on near-infrared and X-ray, and find that the virial factors do not depend on the redshift or obscuration, but some broad lines show a mild anticorrelation with M BH. Our results show the critical impact obscuration can have on BLR characterization and the importance of the near-infrared and X-rays for a less-biased view of the BLR. *This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

Keywords: Active galaxies, X-ray active galactic nuclei, Active galactic nuclei, High energy astrophysics
BASS. XXX. Distribution Functions of DR2 Eddington Ratios, Black Hole Masses, and X-Ray Luminosities. We determine the low-redshift X-ray luminosity function, active black hole mass function (BHMF), and Eddington ratio distribution function (ERDF) for both unobscured (Type 1) and obscured (Type 2) active galactic nuclei (AGNs), using the unprecedented spectroscopic completeness of the BAT AGN Spectroscopic Survey (BASS) data release 2. In addition to a straightforward 1/V max approach, we also compute the intrinsic distributions, accounting for sample truncation by employing a forward-modeling approach to recover the observed BHMF and ERDF. As previous BHMFs and ERDFs have been robustly determined only for samples of bright, broad-line (Type 1) AGNs and/or quasars, ours are the first directly observationally constrained BHMF and ERDF of Type 2 AGNs. We find that after accounting for all observational biases, the intrinsic ERDF of Type 2 AGNs is significantly more skewed toward lower Eddington ratios than the intrinsic ERDF of Type 1 AGNs. This result supports the radiation-regulated unification scenario, in which radiation pressure dictates the geometry of the dusty obscuring structure around an AGN. Calculating the ERDFs in two separate mass bins, we verify that the derived shape is consistent, validating the assumption that the ERDF (shape) is mass-independent. We report the local AGN duty cycle as a function of mass and Eddington ratio, by comparing the BASS active BHMF with the local mass function for all supermassive black holes. We also present the of the Swift/BAT 70 month sources.

Keywords: Luminosity function, Supermassive black holes, Accretion, High energy astrophysics, Quasars, Active galaxies, Active galactic nuclei, X-ray active galactic nuclei, X-ray surveys
High-precision Multichannel Solar Image Registration Using Image Intensity. Solar images observed in different channels with different instruments are crucial to the study of solar activity. However, the images have different fields of view, causing them to be misaligned. It is essential to accurately register the images for studying solar activity from multiple perspectives. Image registration is described as an optimizing problem from an image to be registered to a reference image. In this paper, we proposed a novel coarse-to-fine solar image registration method to register the multichannel solar images. In the coarse registration step, we used the regular step gradient descent algorithm as an optimizer to maximize the normalized cross correlation metric. The fine registration step uses the Powell-Brent algorithms as an optimizer and brings the Mattes mutual information similarity metric to the minimum. We selected five pairs of images with different resolutions, rotation angles, and shifts to compare and evaluate our results to those obtained by scale-invariant feature transform and phase correlation. The images are observed by the 1.6 m Goode Solar Telescope at Big Bear Solar Observatory and the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory. Furthermore, we used the mutual information and registration time criteria to quantify the registration results. The results prove that the proposed method not only reaches better registration precision but also has better robustness. Meanwhile, we want to highlight that the method can also work well for the time-series solar image registration.

Keywords: Astronomical techniques, Computational methods, Astronomy data analysis
Systematically Measuring Ultra-diffuse Galaxies (SMUDGes). III. The Southern SMUDGes Catalog. We present a catalog of 5598 ultra-diffuse galaxy (UDG) candidates with effective radius r  e  &gt; 5.″3 distributed throughout the southern portion of the DESI Legacy Imaging Survey covering ~15,000 deg2. The catalog is most complete for physically large (r  e  &gt; 2.5 kpc) UDGs lying in the redshift range 1800 ≲ cz/km s-1 ≲ 7000, where the lower bound is defined by where incompleteness becomes significant for large objects on the sky and the upper bound by our minimum angular size selection criterion. Because physical size is integral to the definition of a UDG, we develop a method of distance estimation using existing redshift surveys. With three different galaxy samples, two of which contain UDGs with spectroscopic redshifts, we estimate that the method has a redshift accuracy of ~75% when the method converges, although larger, more representative spectroscopic UDG samples are needed in order to fully understand the behavior of the method. We are able to estimate distances for 1079 of our UDG candidates (19%). Finally, to illustrate some uses of the catalog, we present both distance-independent and distance-dependent results. In the latter category, we establish that the red sequence of UDGs lies on the extrapolation of the red sequence relation for bright ellipticals and that the environment-color relation is at least qualitatively similar to that of high surface brightness galaxies. Both of these results challenge some of the models proposed for UDG evolution.

Keywords: Galaxy structure, Low surface brightness galaxies
The Dwarf Galaxy Population at z   0.7: A Catalog of Emission Lines and Redshifts from Deep Keck Observations. We present a catalog of spectroscopically measured redshifts over 0 &lt; z &lt; 2 and emission-line fluxes for 1440 galaxies. The majority (~65%) of the galaxies come from the HALO7D survey, with the remainder from the DEEPwinds program. This catalog includes redshifts for 646 dwarf galaxies with $\mathrm{log}({M}_{\star }/{M}_{\odot })\lt 9.5$ . Eight-hundred and ten catalog galaxies did not have previously published spectroscopic redshifts, including 454 dwarf galaxies. HALO7D used the DEIMOS spectrograph on the Keck II telescope to take very deep (up to 32 hr exposure, with a median of ~7 hr) optical spectroscopy in the COSMOS, EGS, GOODS-North, and GOODS-South CANDELS fields, and in some areas outside CANDELS. We compare our redshift results to existing spectroscopic and photometric redshifts in these fields, finding only a 1% rate of discrepancy with other spectroscopic redshifts. We measure a small increase in median photometric redshift error (from 1.0% to 1.3%) and catastrophic outlier rate (from 3.5% to 8%) with decreasing stellar mass. We obtained successful redshift fits for 75% of massive galaxies, and demonstrate a similar 70%-75% successful redshift measurement rate in $8.5\lt \mathrm{log}({M}_{\star }/{M}_{\odot })\lt 9.5$ galaxies, suggesting similar survey sensitivity in this low-mass range. We describe the redshift, mass, and color-magnitude distributions of the catalog galaxies, finding HALO7D galaxies representative of CANDELS galaxies up to i-band magnitudes of 25. The catalogs presented will enable studies of star formation, the mass-metallicity relation, star formation-morphology relations, and other properties of the z ~ 0.7 dwarf galaxy population.

Keywords: Dwarf galaxies, Emission line galaxies, Star formation, Galaxy spectroscopy, Redshift surveys, Catalogs
Catalog of High-velocity Dispersion Compact Clouds in the Central Molecular Zone of Our Galaxy. This study developed an automated identification procedure for compact clouds with broad velocity widths in the spectral-line data cubes of highly crowded regions. The procedure was applied to the CO J = 3 - 2 line data, obtained using the James Clerk Maxwell Telescope, to identify 184 high-velocity dispersion compact clouds (HVDCCs), which are a category of peculiar molecular clouds found in the central molecular zone of our Galaxy. A list of HVDCCs in the area -1.°4 ≤ l ≤ +2.°0, -0.°25 ≤ b ≤ +0.°25 was presented with their physical parameters, CO J = 3 - 2/J = 1 - 0 intensity ratios, and morphological classifications. Consequently, the list provides several intriguing sources that may have been driven by encounters with pointlike massive objects, local energetic events, or cloud-to-cloud collisions.

Keywords: Galactic center
Water Masers as an Early Tracer of Star Formation. We present a study of the correlation between 22 GHz water maser emission and far-infrared/submillimeter (IR/sub-mm) sources. The generalized linear model (GLM) is used to predict H2O maser detection in a particular source with defined physical parameters. We checked the GLM predictions by observing a sample of selected sources with the Effelsberg 100 m telescope. In total, 359 sources were observed. H2O masers were detected in 124 sources, with 56 new detections. We found 22 sources with a significant flux variability. Using the GLM analysis, we estimate that 2392 ± 339 star formation regions (SFRs) in the Galaxy may harbor H2O masers detectable by single-dish observations at the noise level of ~0.05 Jy. Analyzing the luminosity-to-mass ratio (L/M) of the ATLASGAL and Hi-GAL clumps associated with different maser species, we find that 22 GHz water masers have significantly lower values of L/M in comparison to 6.7 GHz class II methanol and 1665 MHz OH masers. This implies that 22 GHz water masers may appear prior to 6.7 GHz methanol and OH masers in the evolutionary sequence of SFRs. From the analysis of physical offsets between host clumps and maser interferometric positions, we found no significant difference between the H2O and class II methanol maser offsets against the host clump position. We conclude that the tight association between water masers and IR/sub-mm sources may provide insight into the pumping conditions of these masers and the evolutionary stages of their onset.

Keywords: Astronomy databases, Far infrared astronomy, Water masers, Astrophysical masers, Submillimeter astronomy, Radio astronomy
A Publicly Available Multiobservatory Data Set of an Enhanced Network Patch from the Photosphere to the Corona. New instruments sensitive to chromospheric radiation at X-ray, UV, visible, IR, and submillimeter wavelengths have become available that significantly enhance our ability to understand the bidirectional flow of energy through the chromosphere. We describe the calibration, coalignment, initial results, and public release of a new data set combining a large number of these instruments to obtain multiwavelength photospheric, chromospheric, and coronal observations capable of improving our understanding of the connectivity between the photosphere and the corona via transient brightenings and wave signatures. The observations center on a bipolar region of enhanced-network magnetic flux near disk center on SOL2017-03-17T14:00-17:00. The comprehensive data set provides one of the most complete views to date of chromospheric activity related to small-scale brightenings in the corona and chromosphere. Our initial analysis shows a strong spatial correspondence between the areas of broadest width of the hydrogen-α spectral line and the hottest temperatures observed in Atacama Large Millimeter/submillimeter Array (ALMA) Band 3 radio data, with a linear coefficient of 6.12 × 10-5Å/K. The correspondence persists for the duration of cotemporal observations (≍60 m). Numerous transient brightenings were observed in multiple data series. We highlight a single, well-observed transient brightening in a set of thin filamentary features with a duration of 20 minutes. The timing of the peak intensity transitions from the cooler (ALMA, 7000 K) to the hotter (XRT, 3 MK) data series.

Keywords: Solar atmosphere, Solar coronal transients, Solar photosphere, Solar extreme ultraviolet emission, The Sun, Solar x-ray emission, Solar physics, Solar radio emission, Solar corona, Solar chromosphere
Entropy-conserving Scheme for Modeling Nonthermal Energies in Fluid Dynamics Simulations. We compare the performance of energy-based and entropy-conserving schemes for modeling nonthermal energy components, such as unresolved turbulence and cosmic rays, using idealized fluid dynamics tests and isolated galaxy simulations. While both methods are aimed to model advection and adiabatic compression or expansion of different energy components, the energy-based scheme numerically solves the nonconservative equation for the energy density evolution, while the entropy-conserving scheme uses a conservative equation for modified entropy. Using the standard shock tube and Zel'dovich pancake tests, we show that the energy-based scheme results in a spurious generation of nonthermal energy on shocks, while the entropy-conserving method evolves the energy adiabatically to machine precision. We also show that, in simulations of an isolated L ⋆ galaxy, switching between the schemes results in ≈20%-30% changes of the total star formation rate and a significant difference in morphology, particularly near the galaxy center. We also outline and test a simple method that can be used in conjunction with the entropy-conserving scheme to model the injection of nonthermal energies on shocks. Finally, we discuss how the entropy-conserving scheme can be used to capture the kinetic energy dissipated by numerical viscosity into the subgrid turbulent energy implicitly, without explicit source terms that require calibration and can be rather uncertain. Our results indicate that the entropy-conserving scheme is the preferred choice for modeling nonthermal energy components, a conclusion that is equally relevant for Eulerian and moving-mesh fluid dynamics codes.

Keywords: Hydrodynamical simulations, Interstellar dynamics, Stellar feedback, Galaxy evolution, Shocks, Cosmic rays
Data-driven Model of Temporal Evolution of Solar Mg II h and k Profiles over the Solar Cycle. The solar radiation in the cores of the Mg II h and k spectral lines plays a significant role in the illumination of prominences, coronal mass ejections (CMEs), spicules, flare loops, and surges. Moreover, the radiation in these lines strongly correlates with solar magnetic activity and the ultraviolet solar spectral irradiance affecting the photochemistry, especially of oxygen and nitrogen, in the middle atmosphere of the Earth. This work provides a data-driven model of temporal evolution of the solar full-disk Mg II h and k profiles over the solar cycle. The capability of the model to reproduce the Mg II h and k profiles for an arbitrary date is statistically assessed. Based on selected 76 IRIS near-UV full-Sun mosaics covering almost the full solar cycle 24, we find the parameters of double-Gaussian fits of the disk-averaged Mg II h and k profiles and a model of their temporal evolution parameterized by the Bremen composite Mg II index. The model yields intensities within the uncertainties of the observed data in more than 90% of the reconstructed profiles assuming a statistically representative set of Bremen Mg II index values in the range of 0.150-0.165. The relevant full-disk Mg II h and k calibrated profiles with uncertainties and spectral irradiances are provided as an online machine-readable table. The model yields Mg II h and k profiles representing the disk incident radiation for the radiative-transfer modeling of prominences, CMEs, spicules, flare loops, and surges observed at arbitrary time.

Keywords: Solar cycle, Solar chromosphere, Solar ultraviolet emission
One Solar Cycle of Heliosphere Observations with the Interstellar Boundary Explorer: Energetic Neutral Hydrogen Atoms Observed with IBEX-Lo from 10 eV to 2 keV. The Interstellar Boundary Explorer (IBEX) is a NASA satellite in Earth orbit, dedicated to observing both interstellar neutral atoms entering the heliosphere and energetic neutral atoms (ENAs) from the interstellar boundaries from roughly 10 eV to 6 keV. This work presents the averaged maps, energy spectra, and temporal variability of heliospheric ENA intensities measured with the IBEX-Lo instrument at 1 au at energies between 10 eV and 2 keV, covering one entire solar cycle from 2009 through 2019. These results expand the range in time and energy for studying the globally distributed ENA flux and the IBEX Ribbon. The observed ENA intensities exceed model predictions, in particular below 500 eV. Moreover, the ENA intensities between 50-200 eV energy show an unexpected rise and fall around the year 2015 in most sky regions.

Keywords: Heliosheath, Heliosphere
Dynamically Tagged Groups of Metal-poor Stars. II. The Radial Velocity Experiment Data Release 6. Orbital characteristics based on Gaia Early Data Release 3 astrometric parameters are analyzed for ~8000 metal-poor stars ([Fe/H] ≤ -0.8) compiled from the Radial Velocity Experiment (RAVE) Data Release 6. Selected as metal-poor candidates based on broadband photometry, RAVE collected moderate-resolution (R ~ 7500) spectra in the region of the Ca triplet for these stars. About 20% of the stars in this sample also have medium-resolution (1200 ≲ R ≲ 2000) validation spectra obtained over a 4 yr campaign from 2014 to 2017 with a variety of telescopes. We match the candidate stars to photometric metallicity determinations from the Huang et al. recalibration of the SkyMapper Southern Survey Data Release 2. We obtain dynamical clusters of these stars from the orbital energy and cylindrical actions using the HDBSCAN unsupervised learning algorithm. We identify 179 dynamically tagged groups (DTGs) with between 5 and 35 members; 67 DTGs have at least 10 member stars. Milky Way (MW) substructures such as Gaia-Sausage-Enceladus, the Metal-weak Thick Disk, the Splashed Disk, Thamnos, the Helmi Stream, and LMS-1 (Wukong) are identified. Associations with MW globular clusters are determined for 10 DTGs; no recognized MW dwarf galaxies were associated with any of our DTGs. Previously identified dynamical groups are also associated with our DTGs, with emphasis placed on their structural determination and possible new identifications. We identify chemically peculiar stars as members of several DTGs; we find 22 DTGs that are associated with r-process-enhanced stars. Carbon-enhanced metal-poor (CEMP) stars are identified among the targets with available spectroscopy, and we assign these to morphological groups following the approach given by Yoon et al.

Keywords: Milky Way formation, Galactic archaeology, Galaxy dynamics, Milky Way dynamics, Milky Way stellar halo, Milky Way evolution
CoSHA: Code for Stellar Properties Heuristic Assignment-for the MaStar Stellar Library. We introduce COSHA: a Code for Stellar properties Heuristic Assignment. In order to estimate the stellar properties, COSHA implements a Gradient Tree Boosting algorithm to label each star across the parameter space (T eff, $\mathrm{log}g$ , [Fe/H], and [α/Fe]). We use COSHA to estimate the stellar atmospheric parameters of 22,000 unique stars in the MaNGA Stellar Library (MaStar). To quantify the reliability of our approach, we run internal tests, using both the Göttingen Stellar Library (a theoretical library) and the first data release of MaStar, and external tests, by comparing the resulting distributions in the parameter space with the APOGEE estimates of the same properties. In summary, our parameter estimates span the ranges T eff = [2900, 12,000] K, $\mathrm{log}g=[-0.5,5.6]$ , [Fe/H] = [-3.74, 0.81], and α M = [-0.22, 1.17]. We report internal (external) uncertainties of the properties of ${\sigma }_{{T}_{\mathrm{eff}}}\sim 43(240)$ K, ${\sigma }_{\mathrm{log}g}\sim 0.2(0.4)$ , σ [Fe/H] ~ 0.16(0.24), and σ [α/Fe] ~ 0.09(0.08). These uncertainties are comparable to those of other methods with similar objectives. Despite the fact that COSHA is not aware of the spatial distributions of these physical properties in the Milky Way, we are able to recover the main trends known in the literature. The catalog of physical properties for MaStar can be accessed online.

Keywords: Stellar properties, Astrostatistics