Sazuna/UAT_keywords huggingface dataset:
The Southern H II Region Discovery Survey. II. The Full Catalog. The Southern H II Region Discovery Survey (SHRDS) is a 900 hr Australia Telescope Compact Array 4-10 GHz radio continuum and radio recombination line (RRL) survey of Galactic H II regions and infrared-identified H II region candidates in the southern sky. For this data release, we reprocess all previously published SHRDS data and include an additional ∼450 hr of observations. The search for new H II regions is now complete over the range 259° &lt; ℓ &lt; 346°, ∣b∣ &lt; 4° for H II region candidates with predicted 6 GHz continuum peak brightnesses ≳30 mJy beam-1. We detect radio continuum emission toward 730 targets altogether including previously known nebulae and H II region candidates. By averaging ∼18 RRL transitions, we detect RRL emission toward 206 previously known H II regions and 436 H II region candidates. Including the northern sky surveys, over the last decade the H II Region Discovery Surveys have more than doubled the number of known Galactic H II regions. The census of H II regions in the Wide-field Infrared Survey Explorer (WISE) Catalog of Galactic H II Regions is now complete for nebulae with 9 GHz continuum flux densities ≳250 mJy. We compare the RRL properties of the newly discovered SHRDS nebulae with those of all previously known H II regions. The median RRL FWHM line width of the entire WISE Catalog H II region population is 23.9 km s-1 and is consistent between Galactic quadrants. The observed Galactic longitude-velocity asymmetry in the population of H II regions probably reflects underlying spiral structure in the Milky Way.

Keywords: Radio spectroscopy, Surveys, Galaxy structure, Milky Way dynamics, Interstellar medium, Radio continuum emission, H II regions, Milky Way Galaxy
Variations of the Galactic Cosmic Rays in the Recent Solar Cycles. In this paper, we study the Galactic cosmic-ray (GCR) variations over the solar cycles 23 and 24, with measurements from NASA's Advanced Composition Explorer/Cosmic Ray Isotope Spectrometer instrument and the ground-based neutron monitors (NMs). The results show that the maximum GCR intensities of heavy nuclei (5 ≤ Z ≤ 28, 50∼500 MeV nuc-1) at 1 au during the solar minimum in 2019-2020 break their previous records, exceeding those recorded in 1997 and 2009 by ∼25% and ∼6%, respectively, and are at the highest levels since the space age. However, the peak NM count rates are lower than those in late 2009. The difference between GCR intensities and NM count rates still remains to be explained. Furthermore, we find that the GCR modulation environment during the solar minimum P24/25 are significantly different from previous solar minima in several aspects, including remarkably low sunspot numbers, extremely low inclination of the heliospheric current sheet, rare coronal mass ejections, weak interplanetary magnetic field and turbulence. These changes are conducive to reduce the level of solar modulation, providing a plausible explanation for the record-breaking GCR intensities in interplanetary space.

Keywords: Galactic cosmic rays, Solar activity, Interplanetary turbulence
The Ultraviolet Extinction Map and Dust Properties at High Galactic Latitude. Extinction in ultraviolet is much more significant than in optical or infrared, which can be very informative to precisely measure the extinction and understand the dust properties in the low-extinction areas. The high Galactic latitude sky is such an area, important for studying the extragalactic sky and the universe. Based on the stellar parameters measured by the LAMOST and GALAH spectroscopy and the ultraviolet photometry by the Galaxy Evolution Explorer (GALEX) space telescope, the extinction of 1,244,504 stars in the GALEX/near-UV band and 56,123 stars in the GALEX/far-UV band is calculated precisely. The error of color excess is 0.009, 0.128, and 0.454 mag for ${E}_{{G}_{\mathrm{BP}},{G}_{\mathrm{RP}}}$ , ${E}_{\mathrm{NUV},{{\rm{G}}}_{\mathrm{BP}}}$ , and ${E}_{\mathrm{FUV},{{\rm{G}}}_{\mathrm{BP}}}$ , respectively. They delineate the GALEX/near-UV extinction map of about a third of the sky mainly at the high Galactic latitude area with an angular resolution of ∼ 0°4. The mean color excess ratio in the entire sky area is derived to be 3.25, 2.95, and -0.37 for ${E}_{\mathrm{NUV},{{\rm{G}}}_{\mathrm{BP}}}/{E}_{{G}_{\mathrm{BP}},{G}_{\mathrm{RP}}}$ , ${E}_{\mathrm{FUV},{{\rm{G}}}_{\mathrm{BP}}}/{E}_{{G}_{\mathrm{BP}},{G}_{\mathrm{RP}}}$ , and ${E}_{\mathrm{FUV},\mathrm{NUV}}/{E}_{{G}_{\mathrm{BP}},{G}_{\mathrm{RP}}}$ , respectively, which is in general agreement with the previous works, and their changes with the Galactic latitude and the interstellar extinction are discussed.

Keywords: Interstellar dust, Ultraviolet extinction
The TESS Objects of Interest Catalog from the TESS Prime Mission. We present 2241 exoplanet candidates identified with data from the Transiting Exoplanet Survey Satellite (TESS) during its 2 yr Prime Mission. We list these candidates in the TESS Objects of Interest (TOI) Catalog, which includes both new planet candidates found by TESS and previously known planets recovered by TESS observations. We describe the process used to identify TOIs, investigate the characteristics of the new planet candidates, and discuss some notable TESS planet discoveries. The TOI catalog includes an unprecedented number of small planet candidates around nearby bright stars, which are well suited for detailed follow-up observations. The TESS data products for the Prime Mission (sectors 1-26), including the TOI catalog, light curves, full-frame images, and target pixel files, are publicly available at the Mikulski Archive for Space Telescopes.

Keywords: Exoplanet astronomy, Exoplanet catalogs, Exoplanets
A Three-dimensional Map of the Heliosphere from IBEX. The Interstellar Boundary Explorer (IBEX) mission has shown that variations in the energetic neutral atom (ENA) flux from the outer heliosphere are associated with the solar cycle and longer-term variations in the solar wind (SW). In particular, there is a good correlation between the dynamic pressure of the outbound SW and variations in the later-observed IBEX ENA flux. The time difference between observations of the outbound SW and the heliospheric ENAs with which they correlate ranges from approximately 2 to 6 yr or more, depending on ENA energy and look direction. This time difference can be used as a means of "sounding" the heliosheath, that is, finding the average distance to the ENA source region in a particular direction. We apply this method to build a 3D map of the heliosphere. We use IBEX ENA data collected over a complete solar cycle, from 2009 through 2019, corrected for survival probability to the inner heliosphere. Here we divide the data into 56 "macropixels" covering the entire sky. As each point in the sky is sampled once every 6 months, this gives us a time series of 22 points macropixel-1 on which to time-correlate. Consistent with prior studies and heliospheric models, we find that the shortest distance to the heliopause, dHP, is slightly south of the nose direction (dHP ∼ 110-120 au), with a flaring toward the flanks and poles (dHP ∼ 160-180 au). The heliosphere extends at least ∼350 au tailward, which is the distance limit of the technique.

Keywords: Heliopause, Heliosheath, Solar wind termination, Heliosphere
Predicting Localized Primordial Star Formation with Deep Convolutional Neural Networks. We investigate applying 3D deep convolutional neural networks as fast surrogate models of the formation and feedback effects of primordial stars in hydrodynamic cosmological simulations of the first galaxies. Here, we present the surrogate model to predict localized primordial star formation; the feedback model will be presented in a subsequent paper. The star formation prediction model consists of two submodels: the first is a 3D volume classifier that predicts which (10 comoving kpc)3 volumes will host star formation, followed by a 3D Inception-based U-net voxel segmentation model that predicts which voxels will form primordial stars. We find that the combined model predicts primordial star-forming volumes with high skill, with F1 &gt; 0.995 and true skill score (TSS) &gt;0.994. The star formation is localized within the volume to ≲53 voxels (∼1.6 comoving kpc3) with F1 &gt; 0.399 and TSS &gt;0.857. Applied to simulations with low spatial resolution, the model predicts star-forming regions in the same locations and at similar redshifts as sites in resolved full-physics simulations that explicitly model primordial star formation and feedback. When applied to simulations with lower mass resolution, we find that the model predicts star-forming regions at later redshift due to delayed structure formation resulting from lower mass resolution. Our model predicts primordial star formation without halo finding, so it will be useful in spatially under-resolved simulations that cannot resolve primordial star-forming halos. To our knowledge, this is the first model that can predict primordial star-forming regions that match highly resolved cosmological simulations.

Keywords: Convolutional neural networks, Population III stars
The Hipparcos-Gaia Catalog of Accelerations: Gaia EDR3 Edition. We present a cross-calibration of Hipparcos and Gaia EDR3 intended to identify astrometrically accelerating stars and to fit orbits to stars with faint, massive companions. The resulting catalog, the EDR3 edition of the Hipparcos-Gaia Catalog of Accelerations (HGCA), provides three proper motions with calibrated uncertainties on the EDR3 reference frame: the Hipparcos proper motion, the Gaia EDR3 proper motion, and the long-term proper motion given by the difference in position between Hipparcos and Gaia EDR3. Our approach is similar to that for the Gaia DR2 edition of the HGCA but offers a factor of ∼3 improvement in precision thanks to the longer time baseline and improved data processing of Gaia EDR3. We again find that a 60/40 mixture of the two Hipparcos reductions outperforms either reduction individually, and we find strong evidence for locally variable frame rotations between all pairs of proper motion measurements. The substantial global frame rotation seen in DR2 proper motions has been removed in EDR3. We also correct for color- and magnitude-dependent frame rotations at a level of up to ∼50 μas yr-1 in Gaia EDR3. We calibrate the Gaia EDR3 uncertainties using a sample of radial velocity standard stars without binary companions; we find an error inflation factor (a ratio of total to formal uncertainty) of 1.37. This is substantially lower than the position-dependent factor of ∼1.7 found for Gaia DR2 and reflects the improved data processing in EDR3. While the catalog should be used with caution, its proper motion residuals provide a powerful tool to measure the masses and orbits of faint, massive companions to nearby stars.

Keywords: Astrometric exoplanet detection, Astrometric binary stars, Astrometry
Likelihood-free Cosmological Constraints with Artificial Neural Networks: An Application on Hubble Parameters and SNe Ia. The errors of cosmological data generated from complex processes, such as the observational Hubble parameter data (OHD) and the Type Ia supernova (SN Ia) data, cannot be accurately modeled by simple analytical probability distributions, e.g., a Gaussian distribution. To constrain cosmological parameters from these data, likelihood-free inference is usually used to bypass the direct calculation of the likelihood. In this paper, we propose a new procedure to perform likelihood-free cosmological inference using two artificial neural networks (ANNs), the masked autoregressive flow (MAF) and the denoising autoencoder (DAE). Our procedure is the first to use DAE to extract features from data, in order to simplify the structure of MAF needed to estimate the posterior. Tested on simulated Hubble parameter data with a simple Gaussian likelihood, the procedure shows the capability of extracting features from data and estimating posterior distributions without the need of tractable likelihood. We demonstrate that it can accurately approximate the real posterior, achieve performance comparable to the traditional Markov chain Monte Carlo method, and MAF obtains better training results for a small number of simulation when the DAE is added. We also discuss the application of the proposed procedure to OHD and Pantheon SN Ia data, and use them to constrain cosmological parameters from the non-flat ΛCDM model. For SNe Ia, we use fitted light-curve parameters to find constraints on H0, Ωm, and ΩΛ similar to relevant work, using less empirical distributions. In addition, this work is also the first to use a Gaussian process in the procedure of OHD simulation.

Keywords: Cosmological parameters, Neural networks, Observational cosmology, Astronomy data analysis, Computational methods, Astrostatistics strategies
Investigation of the Long-term Variation of Solar Ca II K Intensity. I. Density-to-intensity Calibration Formula for Historical Photographic Plates. This paper presents a novel formula to convert photographic density into intensity for historical photographic plates of the Sun. Photographic photometry is of great importance as the very first step of analyzing century-long archived photographic data to study the long-term variation. The calibration formula is newly developed by using the intensity fluctuation originating in the network pattern in the quiet region, taking into consideration the nonlinearity between the density and the intensity. The formula is useful especially when experimentally obtained characteristic curves are insufficient for homogeneous analysis of a whole long-term data set. An example procedure of the calibration using the formula is demonstrated. Resultant intensity images calibrated from the photographic data can reproduce both the fluctuation and the center-to-limb variation of modern reference data. The calibration procedure is also tested with a whole twentieth century data set and shows good performance, while the preliminary result of the long-term intensity variation seems to be partially affected by the quality of the original plates. The resultant solar Ca II K intensity variation will be updated and discussed in a subsequent paper with the comparison to the solar UV variation related to the terrestrial environment.

Keywords: Solar cycle, Astronomy data analysis, Solar electromagnetic emission, Photoheliographs, Solar chromosphere
Classification of OGLE Eclipsing Binary Stars Based on Their Morphology Type with Locally Linear Embedding. The Optical Gravitational Lensing Experiment (OGLE) continuously monitors hundreds of thousands of eclipsing binaries in the Galactic bulge field and the Magellanic Clouds. These objects have been classified into major morphological subclasses, such as contact, noncontact, ellipsoidal, and cataclysmic variables, both by matching the light curves with predefined templates and by visual inspections. Here we present the result of a machine-learned automatic classification based on the morphology of light curves inspired by the classification of eclipsing binaries observed by the original Kepler mission. We similarly use a dimensionality reduction technique with locally linear embedding to map the high dimension of the data set into a low-dimensional embedding parameter space, while keeping the local geometry and the similarities of the neighboring data points. After three consecutive steps, we assign one parameter to each binary star, which scales well with the detachness, i.e., the sum of the relative radii of the components. This value is in good agreement with the morphology types listed in the OGLE catalog and, along with the orbital periods, can be used to filter any morphological subtypes based on the similarity of light curves. Our open-source pipeline can be applied in a fully automatic way to any other large data set to classify binary stars.

Keywords: Eclipsing binary stars, Astronomy databases, Astronomy data analysis
Mid-J CO Line Observations of Protostellar Outflows in the Orion Molecular Clouds. Ten protostellar outflows in the Orion molecular clouds were mapped in the 12CO/13CO J 6 5 and 12CO J 7 6 lines. The maps of these mid-J CO lines have an angular resolution of about 10 and a typical field size of about 100. The physical parameters of the molecular outflows were derived, including mass transfer rates, kinetic luminosities, and outflow forces. The outflow sample was expanded by reanalyzing archival data of nearby low-luminosity protostars to cover a wide range of bolometric luminosities. Outflow parameters derived from other transitions of CO were compared. The mid-J (Jup 6) and low-J (Jup 3) CO line wings trace essentially the same outflow component. By contrast, the high-J (up to Jup 50) line-emission luminosity of CO shows little correlation with the kinetic luminosity from the J 6 5 line, which suggests that they trace distinct components. The low-/mid-J CO line wings trace long-term outflow behaviors, while the high-J CO lines are sensitive to short-term activities. The correlations between the outflow parameters and protostellar properties are presented, which shows that the strengths of molecular outflows increase with bolometric luminosity and envelope mass.

Keywords: Stellar jets, Star formation, CO line emission, Protostars, Radio astronomy
Radiative Transfer with Opacity Distribution Functions: Application to Narrowband Filters. Modeling of stellar radiative intensities in various spectral passbands plays an important role in stellar physics. At the same time, direct calculation of the high-resolution spectrum and then integration of it over the given spectral passband is computationally demanding due to the vast number of atomic and molecular lines. This is particularly so when employing three-dimensional (3D) models of stellar atmospheres. To accelerate the calculations, one can employ approximate methods, e.g., the use of opacity distribution functions (ODFs). Generally, ODFs provide a good approximation of traditional spectral synthesis, i.e., computation of intensities through filters with strictly rectangular transmission functions. However, their performance strongly deteriorates when the filter transmission noticeably changes within its passband, which is the case for almost all filters routinely used in stellar physics. In this context, the aims of this paper are (a) to generalize the ODFs method for calculating intensities through filters with arbitrary transmission functions, and (b) to study the performance of the standard and generalized ODFs methods for calculating intensities emergent from 3D models of stellar atmospheres. For this purpose we use the newly developed MPS-ATLAS radiative transfer code to compute intensities emergent from 3D cubes simulated with the radiative magnetohydrodynamics code MURaM. The calculations are performed in the 1.5D regime, i.e., along many parallel rays passing through the simulated cube. We demonstrate that the generalized ODFs method allows accurate and fast syntheses of spectral intensities and their center-to-limb variations.

Keywords: Stellar atmospheric opacity, Exoplanet astronomy, Radiative transfer equation, Radiative transfer, Stellar atmospheres
Determination of Rotation Periods for a Large Sample of Asteroids from the K2 Campaign 9. The Kepler mission is a powerful tool for the study of different types of astrophysical objects or events in the distant universe. However, the spacecraft also provides an opportunity to study solar system objects passing in the telescope's field of view. The aim of this paper is to determine, for the first time, the rotation periods of a number of asteroids observed by the K2 satellite during the K2 Campaign 9. Using publicly available data from the Kepler mission, we have used the Modified Causal Pixel Model code to perform the aperture-like and point-response function-like photometry of 1026 asteroids. The results allowed us to determine the rotation periods for 188 asteroids. For asteroids with rotation periods that were previously measured, we compared the results and found very good agreement. There are an additional 20 asteroids for which we obtained lower limits on rotation periods and in all cases these limits are at least 100 hr.

Keywords: Asteroids, Small Solar System bodies
The CHIME Pulsar Project: System Overview. We present the design, implementation, and performance of the digital pulsar observing system constructed for the Canadian Hydrogen Intensity Mapping Experiment (CHIME). Using accelerated computing, this system processes independent, digitally steered beams formed by the CHIME correlator to simultaneously observe up to 10 radio pulsars and transient sources. Each of these independent streams is processed by the CHIME/Pulsar back-end system, which can coherently dedisperse, in real time, up to dispersion measure values of 2500 pc cm-3. The tracking beams and real-time analysis system are autonomously controlled by a priority-based algorithm that schedules both known sources and positions of interest for observation with observing cadences as rapid as 1 day. Given the distribution of known pulsars and radio-transient sources and the dynamic scheduling, the CHIME/Pulsar system can monitor 400-500 positions once per sidereal day and observe most sources with declinations greater than -20° once every ~4 weeks. We also discuss the extensive science program enabled through the current modes of data acquisition for CHIME/Pulsar that centers on timing and searching experiments.

Keywords: Pulsar timing method, Astronomy data acquisition, Astronomy data analysis, Astronomical instrumentation, Radio astronomy, Radio pulsars
Warm Jupiters in TESS Full-frame Images: A Catalog and Observed Eccentricity Distribution for Year 1. Warm Jupiters-defined here as planets larger than 6 Earth radii with orbital periods of 8-200 days-are a key missing piece in our understanding of how planetary systems form and evolve. It is currently debated whether Warm Jupiters form in situ, undergo disk or high-eccentricity tidal migration, or have a mixture of origin channels. These different classes of origin channels lead to different expectations for Warm Jupiters' properties, which are currently difficult to evaluate due to the small sample size. We take advantage of the Transiting Exoplanet Survey Satellite (TESS) survey and systematically search for Warm Jupiter candidates around main-sequence host stars brighter than the TESS-band magnitude of 12 in the full-frame images in Year 1 of the TESS Prime Mission data. We introduce a catalog of 55 Warm Jupiter candidates, including 19 candidates that were not originally released as TESS objects of interest by the TESS team. We fit their TESS light curves, characterize their eccentricities and transit-timing variations, and prioritize a list for ground-based follow-up and TESS Extended Mission observations. Using hierarchical Bayesian modeling, we find the preliminary eccentricity distributions of our Warm-Jupiter-candidate catalog using a beta distribution, a Rayleigh distribution, and a two-component Gaussian distribution as the functional forms of the eccentricity distribution. Additional follow-up observations will be required to clean the sample of false positives for a full statistical study, derive the orbital solutions to break the eccentricity degeneracy, and provide mass measurements.

Keywords: Exoplanet catalogs