Sazuna/UAT_keywords huggingface dataset:
Measuring Solar Differential Rotation with an Iterative Phase Correlation Method. A reliable inference of the differential rotation rate of the solar photosphere is essential for models of the solar interior. The work presented here is based on a novel iterative phase correlation technique, which relies on the measurement of the local shift, at the central meridian, between two images separated by a given time interval. Consequently, it does not require any specific reference features, such as sunspots or supergranules, nor extended observations spanning several months. The reliability of the method is demonstrated by applying it to high spatial and temporal resolution continuum images of the solar photosphere, at 6173 Å, acquired by the Solar Dynamics Observatory Helioseismic and Magnetic Imager over one complete Carrington rotation. The data selected covers the time period of 2020 January 1 to February 2. The method was applied to one day, and to the full time interval. The differential rotation rate derived using this feature-independent technique yields values that fall in the middle of the range of those published to date. Most importantly, the method is suited for the production of detailed rotation maps of the solar photosphere. It also enables the visual and quantitative identification of the north-south asymmetry in the solar differential rotation rate, when present.

Keywords: Astronomical models, Solar rotation, Solar differential rotation, Astronomy software, Astronomy data analysis, Analytical mathematics, Astronomical techniques, Computational methods, Direct imaging, Astrometry, Astronomy data visualization, Astronomical methods
Proton and Hydrogen Transport through Hydrogen Environments: Ionization and Stripping. Data are presented over a wide range of impact energies describing the ionization or stripping probability, projectile energy loss, and ejected electron and recoiling target energies and angles for proton and hydrogen passage through hydrogen astrophysical environments. These kinematic and reaction data are tabulated at three levels of detail for use in heavy-particle (H+, H) and secondary-electron transport simulations: (1) the integral scattering cross section and average values of the distributions of energy and angle of the particles, (2) the singly differential cross sections as a function of particle energy and angle, and (3) a subset of the many possible doubly differential cross sections as functions of the particle energy and angle chosen to be most relevant to transport simulations.

Keywords: Laboratory astrophysics, Supernova remnants, Collision physics, Stellar winds, Interstellar medium
Measuring the Metallicity of Early-type Galaxies. I. Composite Region. We present the data of 9739 early-type galaxies (ETGs), cross-matching Galaxy Zoo 1 with our sample selected from the catalog of the Sloan Digital Sky Survey Data Release 7 of MPA-JHU emission-line measurements. We first investigate the divisor between ETGs with and without star formation (SF), and find the best separator of W2-W3 = 2.0 is added. We explore the ETG sample by refusing a variety of ionization sources, and derive 5376 ETGs with SF by utilizing a diagnostic tool of the division line of W2-W3 = 2.0. We measure their metallicities with four abundance calibrators. We find that our composite ETG sample has similar distributions of M* and star formation rate as star-forming galaxies (SFGs) do, that most of them lie on the "main sequence," and that our fit is a slightly steeper slope than that derived in Renzini &amp; Peng. Compared with the distributions between different metallicities calibrated by four abundance indicators, we find that the Curti17 method is the most accurate calibrator for composite ETGs among the four abundance indicators. We present a weak positive correlation of SFR and metallicity only when the metallicity is calibrated by the PP04, Curti17, and T04 indicators. The correlation is not consistent with the negative correlation of both parameters in SFGs. We suggest that the weak correlation is due to the dilution effect of gas inflow driven by minor mergers.

Keywords: Galaxy abundances, Galaxy evolution, Early-type galaxies
Analysis of Coronal Mass Ejection Flux Rope Signatures Using 3DCORE and Approximate Bayesian Computation. We present a major update to the 3D coronal rope ejection (3DCORE) technique for modeling coronal mass ejection flux ropes in conjunction with an approximate Bayesian computation (ABC) algorithm that is used for fitting the model to in situ magnetic field measurements. The model assumes an empirically motivated torus-like flux rope structure that expands self-similarly within the heliosphere, is influenced by a simplified interaction with the solar wind environment, and carries along an embedded analytical magnetic field. The improved 3DCORE implementation allows us to generate extremely large ensemble simulations that we then use to find global best-fit model parameters using an ABC sequential Monte Carlo algorithm. The usage of this algorithm, under some basic assumptions on the uncertainty of the magnetic field measurements, allows us to furthermore generate estimates on the uncertainty of model parameters using only a single in situ observation. We apply our model to synthetically generated measurements to prove the validity of our implementation for the fitting procedure. We also present a brief analysis, within the scope of our model, of an event captured by the Parker Solar Probe shortly after its first flyby of the Sun on 2018 November 12 at 0.25 au. The presented toolset is also easily extendable to the analysis of events captured by multiple spacecraft and will therefore facilitate future multipoint studies.

Keywords: Solar coronal mass ejections
The Spectrum and Term Analysis of Singly Ionized Manganese. An extensive analysis of the Mn spectrum was carried out using high-resolution Fourier transform (FT) and grating spectroscopy of Mn-Ne and Mn-Ar hollow cathode discharge sources, over the range 82-5500 nm (1820-121,728 cm-1). Spectral wavelengths for a total of 6019 Mn II lines have been measured, of which 1345 are obtained through FT spectroscopy. These wavelengths are given to at least an order of magnitude lower uncertainty than previous measurements. These lines were used to identify 6256 Mn II transitions and improve the values of 505 previously published energy levels with typical uncertainties of a few thousandths of a cm-1, representing an order-of-magnitude reduction in uncertainty. We have verified and improved an additional 57 Mn II energy levels, previously established through observation of stellar spectra alone, using our FT spectra. In addition, 52 new energy level values have been established. The number of classified lines reported is approximately 50% more than previously published. The new accurate data for 614 energy levels and 6019 lines will allow a more reliable analysis of Mn II spectral lines in astrophysical spectra.

Keywords: Spectral line lists, Line positions, Spectral line identification, Laboratory astrophysics, Experimental techniques, Stellar atmospheric opacity, Atomic spectroscopy, Spectroscopy, Atomic data benchmarking, Stellar spectral lines
Solar Bayesian Analysis Toolkit—A New Markov Chain Monte Carlo IDL Code for Bayesian Parameter Inference. We present the Solar Bayesian Analysis Toolkit (SoBAT), which is a new easy to use tool for Bayesian analysis of observational data, including parameter inference and model comparison. SoBAT is aimed (but not limited) to be used for the analysis of solar observational data. We describe a new IDL code designed to facilitate the comparison of a user-supplied model with data. Bayesian inference allows prior information to be taken into account. The use of Markov Chain Monte Carlo sampling allows efficient exploration of large parameter spaces and provides reliable estimation of model parameters and their uncertainties. The Bayesian evidence for different models can be used for quantitative comparison. The code is tested to demonstrate its ability to accurately recover a variety of parameter probability distributions. Its application to practical problems is demonstrated using studies of the structure and oscillation of coronal loops.

Keywords: Bayesian statistics, Astronomy software, Astronomy data analysis, Solar physics, Markov chain Monte Carlo
POWDERDAY: Dust Radiative Transfer for Galaxy Simulations. We present POWDERDAY (available at https://github.com/dnarayanan/powderday), a flexible, fast, open-source dust radiative transfer package designed to interface with both idealized and cosmological galaxy formation simulations. POWDERDAY builds on FSPS stellar population synthesis models, and HYPERION dust radiative transfer, and employs YT to interface between different software packages. We include our stellar population synthesis modeling on the fly, allowing significant flexibility in the assumed stellar physics and nebular line emission. The dust content follows either simple observationally motivated prescriptions (i.e., constant dust-to-metals ratios, or dust-to-gas ratios that vary with metallicity), direct modeling from galaxy formation simulations that include dust physics, as well as a novel approach that includes the dust content via learning-based algorithms from the SIMBA cosmological galaxy formation simulation. Active galactic nuclei (AGNs) can additionally be included via a range of prescriptions. The output of these models are broadband (912 Å-1 mm) spectral energy distributions (SEDs), as well as filter-convolved monochromatic images. POWDERDAY is designed to eliminate last-mile efforts by researchers that employ different hydrodynamic galaxy formation models and seamlessly interfaces with GIZMO, AREPO, GASOLINE, CHANGA, and ENZO. We demonstrate the capabilities of the code via three applications: a model for the star formation rate-infrared luminosity relation in galaxies (including the impact of AGNs), the impact of circumstellar dust around AGB stars on the mid-infrared emission from galaxy SEDs, and the impact of galaxy inclination angle on dust attenuation laws.

Keywords: Open source software, Astronomy software, Galaxy evolution, Radiative transfer simulations, Galaxy luminosities
First Fermi-LAT Solar Flare Catalog. We present the first Fermi-Large Area Telescope (LAT) solar flare catalog covering the 24th solar cycle. This catalog contains 45 Fermi-LAT solar flares (FLSFs) with emission in the γ-ray energy band (30 MeV-10 GeV) detected with a significance of ≥5σ over the years 2010-2018. A subsample containing 37 of these flares exhibits delayed emission beyond the prompt-impulsive hard X-ray phase, with 21 flares showing delayed emission lasting more than two hours. No prompt-impulsive emission is detected in four of these flares. We also present in this catalog observations of GeV emission from three flares originating from active regions located behind the limb of the visible solar disk. We report the lightcurves, spectra, best proton index, and localization (when possible) for all FLSFs. The γ-ray spectra are consistent with the decay of pions produced by &gt;300 MeV protons. This work contains the largest sample of high-energy γ-ray flares ever reported and provides a unique opportunity to perform population studies on the different phases of the flare and thus allowing a new window in solar physics to be opened.

Keywords: Solar flares, Gamma-ray sources, Solar gamma-ray emission, Gamma-ray telescopes, Catalogs
Efficient Direct Method for Self-gravity in 3D, Accelerated by a Fast Fourier Transform. Self-gravity calculations for 3D are expensive in terms of computational time. Several methods exist for this computation, for example multigrid and spectral methods. Unfortunately, these approaches require the imposition of boundary conditions, which can be either numerically expensive (direct Newtonian sums), artificial (periodicity assumptions), or potentially imprecise (multipolar expansions). In this work we present a novel direct numerical method to calculate the gravitational potential and forces by solving the Poisson equation without the need to prescribe artificial boundary conditions; this method, despite being direct, turns out to be efficient due to the possibility of using a fast Fourier transform for its implementation. For a grid having N zones in each dimension, the computational complexity of the method presented here is $O({N}^{3}\mathrm{log}{N}^{3})$ , which is comparable with multigrid methods under no consideration of boundary settings. Finally, a numerical study shows this proposed method can achieve second order for calculations of both potential and forces.

Keywords: Fast Fourier transform
Placing High-redshift Quasars in Perspective: A Catalog of Spectroscopic Properties from the Gemini Near Infrared Spectrograph-Distant Quasar Survey. We present spectroscopic measurements for 226 sources from the Gemini Near Infrared Spectrograph-Distant Quasar Survey (GNIRS-DQS). Being the largest uniform, homogeneous survey of its kind, it represents a flux-limited sample (mi ≲ 19.0 mag, H ≲ 16.5 mag) of Sloan Digital Sky Survey (SDSS) quasars at 1.5 ≲ z ≲ 3.5 with a monochromatic luminosity ( $\lambda {L}_{\lambda }$ ) at 5100 Å in the range of 1044-1046 erg s-1. A combination of the GNIRS and SDSS spectra covers principal quasar diagnostic features, chiefly the C IV λ1549, Mg II λλ2798, 2803, Hβ λ4861, and [O III] λλ4959, 5007 emission lines, in each source. The spectral inventory will be utilized primarily to develop prescriptions for obtaining more accurate and precise redshifts, black hole masses, and accretion rates for all quasars. Additionally, the measurements will facilitate an understanding of the dependence of rest-frame ultraviolet-optical spectral properties of quasars on redshift, luminosity, and Eddington ratio, and test whether the physical properties of the quasar central engine evolve over cosmic time.

Keywords: Surveys, Active galactic nuclei, Catalogs, Quasars
Temporal Properties of Precursors, Main Peaks, and Extended Emissions of Short GRBs in the Third Swift/BAT GRB Catalog. A comprehensive study is given to short gamma-ray bursts (sGRBs) in the third Swift Burst Alert Telescope (BAT) GRB Catalog from 2004 December to 2019 July. We examine in detail the temporal properties of the three components in the prompt gamma-ray emission phase, including precursors, main peaks, and extended emissions (EEs). We investigate the similarity of the main peaks between one-component and two-component sGRBs. It is found that there is no substantial difference among their main peaks. Importantly, comparisons are made between in the single-peaked sGRBs and the double-peaked sGRBs. It is found that our results for main peaks in Swift/BAT sGRBs are essentially consistent with those in the Compton Gamma Ray Observatory Burst And Transient Source Experiment (BATSE) ones recently found in our Paper I. Interestingly, we suspect, besides the newly found MODE I/II evolution forms of pulses in BATSE sGRBs in Paper I, that there would have been more evolution modes of pulses across differently adjacent energy channels in view of the Swift/BAT observations. We further inspect the correlation of the main peaks with either the precursors or the EEs. We find that the main peaks tend to last longer than the precursors but shorter than the EEs. Moreover, we verify the power-law correlations related with peak fluxes of the three components, strongly suggesting that they are produced from the similar central-engine activities. In particular, we compare the temporal properties of GRB 170817A with other sGRBs with EE and find no obvious differences between them.

Keywords: Gamma-ray bursts
Radio Counterparts of Gamma-Ray Sources in the Cygnus Region. The view of the gamma-ray universe is being continuously expanded by space high-energy (HE) and ground-based very-high-energy (VHE) observatories. Yet, the angular resolution limitation still precludes a straightforward identification of these gamma-ray emitting sources. Radio observations are an effective tool for searching their possible counterparts at lower energies because the same population of relativistic electrons responsible for radio emission can also produce HE/VHE emission via inverse-Compton scattering. The Cygnus region is crowded by many gamma-ray sources, most of them remaining unidentified. In order to find possible counterparts to unidentified gamma-ray sources, we carried out a deep survey of the Cygnus region using the Giant Metrewave Radio Telescope at 610 and 325 MHz. We did a detailed search for counterparts in the error circle of HE/VHE sources. We report 36 radio sources found in the error ellipse of 15 HE sources, and 11 in those of VHE sources. Eight sources have a very steep radio spectral index α &lt; -1.5, these are most likely to be pulsars and will be followed up for a periodicity search. Such a significant number of pulsar candidates within the error circle of HE/VHE sources prompts a fresh look at the energetics and efficacy of pulsars and pulsar wind nebulae in this context.

Keywords: Gamma-ray sources, Surveys, Pulsars, Supernova remnants, Radio continuum emission, Catalogs
Shadows in the Dark: Low-surface-brightness Galaxies Discovered in the Dark Energy Survey. We present a catalog of 23,790 extended low-surface-brightness galaxies (LSBGs) identified in $\sim 5000\,{\deg }^{2}$ from the first three years of imaging data from the Dark Energy Survey (DES). Based on a single-component Sérsic model fit, we define extended LSBGs as galaxies with g-band effective radii ${R}_{\mathrm{eff}}(g)\gt 2\buildrel{\prime\prime}\over{.} 5$ and mean surface brightness ${\bar{\mu }}_{\mathrm{eff}}(g)\gt 24.2\,\mathrm{mag}\,{\mathrm{arcsec}}^{-2}$ . We find that the distribution of LSBGs is strongly bimodal in (g - r) versus (g - i) color space. We divide our sample into red (g - i ≥ 0.60) and blue (g - i &lt; 0.60) galaxies and study the properties of the two populations. Redder LSBGs are more clustered than their blue counterparts and are correlated with the distribution of nearby (z &lt; 0.10) bright galaxies. Red LSBGs constitute ∼33% of our LSBG sample, and $\sim 30 \% $ of these are located within 1° of low-redshift galaxy groups and clusters (compared to ∼8% of the blue LSBGs). For nine of the most prominent galaxy groups and clusters, we calculate the physical properties of associated LSBGs assuming a redshift derived from the host system. In these systems, we identify 41 objects that can be classified as ultradiffuse galaxies, defined as LSBGs with projected physical effective radii ${R}_{\mathrm{eff}}\gt 1.5\,\mathrm{kpc}$ and central surface brightness ${\mu }_{0}(g)\gt 24.0\,\mathrm{mag}\,{\mathrm{arcsec}}^{-2}$ . The wide-area sample of LSBGs in DES can be used to test the role of environment on models of LSBG formation and evolution.

Keywords: Sky surveys, Low surface brightness galaxies
The Last Journey. I. An Extreme-scale Simulation on the Mira Supercomputer. The Last Journey is a large-volume, gravity-only, cosmological N-body simulation evolving more than 1.24 trillion particles in a periodic box with a side length of 5.025 Gpc. It was implemented using the HACC simulation and analysis framework on the BG/Q system Mira. The cosmological parameters are chosen to be consistent with the results from the Planck satellite. A range of analysis tools have been run in situ to enable a diverse set of science projects and, at the same time, keep the resulting data amount manageable. Analysis outputs have been generated starting at redshift z ∼ 10 to allow for construction of synthetic galaxy catalogs using a semianalytic modeling approach in postprocessing. As part of our in situ analysis pipeline, we employ a new method for tracking halo substructures, introducing the concept of subhalo cores. The production of multiwavelength synthetic sky maps is facilitated by generating particle light cones in situ, also beginning at z ∼ 10. We provide an overview of the simulation setup and generated data products; a first set of analysis results is presented. A subset of the data is publicly available.

Keywords: Cosmology, N-body simulations, Large-scale structure of the universe
A Survey of Three Isotopologues of CO in Molecular Clouds in the CMa OB1 Complex. Using the Purple Mountain Observatory 13.7 m millimeter telescope at Delingha in China, we have conducted a large-scale simultaneous survey of 12CO, 13CO, and C18O (J = 1-0) toward the CMa OB1 complex with a sky coverage of 16.5 deg2 (221.5° ≤ l ≤ 227°, -2.5° ≤ b ≤ 0.5°). Emission from the CMa OB1 complex is found in the range 7 km s-1 ≤ VLSR ≤ 25 km s-1. The large-scale structure, physical properties, and chemical abundances of the molecular clouds are presented. A total of 83 C18O molecular clumps are identified with the GaussClumps algorithm within the mapped region. We find that 94% of these C18O molecular clumps are gravitationally bound. The relationship between their size and mass indicates that none of the C18O clumps has the potential to form high-mass stars. Using a semiautomatic IDL algorithm, we newly discover 85 CO outflow candidates in the mapped area, including 23 bipolar outflow candidates. Additionally, a comparative study reveals evidence for a significant variety of physical properties, evolutionary stages, and levels of star formation activity in different subregions of the CMa OB1 complex.

Keywords: Star formation, Jets, Interstellar molecules
A Multiwavelength Survey of Wolf-Rayet Nebulae in the Large Magellanic Cloud. Surveys of Wolf-Rayet (WR) stars in the Large Magellanic Cloud (LMC) have yielded a fairly complete catalog of 154 known stars. We have conducted a comprehensive, multiwavelength study of the interstellar/circumstellar environments of WR stars, using the Magellanic Cloud Emission Line Survey images in the Hα, [O III], and [S II] lines; Spitzer Space Telescope 8 and 24 μm images; Blanco 4 m Telescope Hα CCD images; and Australian Telescope Compact Array + Parkes Telescope H I data cube of the LMC. We have also examined whether the WR stars are in OB associations, classified the H II environments of WR stars, and used this information to qualitatively assess the WR stars' evolutionary stages. The 30 Dor giant H II region has active star formation and hosts young massive clusters, thus we have made statistical analyses for 30 Dor and the rest of the LMC both separately and altogether. Due to the presence of massive young clusters, the WR population in 30 Dor is quite different from that from elsewhere in the LMC. We find small bubbles (&lt;50 pc diameter) around ∼12% of WR stars in the LMC, most of which are WN stars and not in OB associations. The scarcity of small WR bubbles is discussed. Spectroscopic analyses of abundances are needed to determine whether the small WR bubbles contain interstellar medium or circumstellar medium. Implications of the statistics of interstellar environments and OB associations around WR stars are discussed. Multiwavelength images of each LMC WR star are presented.

Keywords: Wolf-Rayet stars, Interstellar medium, Large Magellanic Cloud, Stellar wind bubbles