Sazuna/UAT_keywords huggingface dataset:
Deuterated Polycyclic Aromatic Hydrocarbons in the Interstellar Medium: The C-D Band Strengths of Monodeuterated Species. Deuterium (D) is one of the light elements created in the Big Bang. As the Galaxy evolves, the D/H abundance in the interstellar medium (ISM) decreases from its primordial value due to astration. However, the observed gas-phase D/H abundances of some sightlines in the local Galactic ISM are substantially lower than the expected reduction by astration. The missing D could have been depleted onto polycyclic aromatic hydrocarbon (PAH) molecules which are ubiquitous and abundant in interstellar regions. To quantitatively explore the hypothesis of PAHs as a possible reservoir of interstellar D, we quantum-chemically compute the infrared vibrational spectra of monodeuterated PAHs and their cations. We find that, as expected, when H in PAHs is replaced by D, the C-H stretching and bending modes at 3.3, 8.6, and 11.3 μm shift to longer wavelengths at ∼4.4, 11.4, and 15.4 μm, respectively, by a factor of ∼ $\sqrt{13/7}$ , the difference in reduced mass between the C-H and C-D oscillators. From the computed spectra we derive the mean intrinsic band strengths of the 3.3 μm C-H stretch and 4.4 μm C-D stretch to be $\langle {A}_{3.3}\rangle \approx 13.2\,\mathrm{km}\,{\mathrm{mol}}^{-1}$ and $\langle {A}_{4.4}\rangle \approx 7.3\,\mathrm{km}\,{\mathrm{mol}}^{-1}$ for neutral deuterated PAHs which would dominate the interstellar emission at 3.3 and 4.4 μm. By comparing the computationally derived mean band-strength ratio of $\langle {A}_{4.4}/{A}_{3.3}\rangle \approx 0.56$ for neutral PAHs with the mean ratio of the observed intensities of $\langle {I}_{4.4}/{I}_{3.3}\rangle \approx 0.019$ , we find that the degree of deuteration (i.e., the fraction of peripheral atoms attached to C atoms in the form of D) is ∼2.4%, corresponding to a D enrichment of a factor of ∼1200 with respect to the interstellar D/H abundance.

Keywords: Interstellar molecules, Interstellar line emission, Polycyclic aromatic hydrocarbons, Astrochemistry, Line intensities
Comparisons of Different Fitting Methods for the Physical Parameters of a Star Cluster Sample of M33 with Spectroscopy and Photometry. Star clusters are good tracers for formation and evolution of galaxies. We compared different fitting methods by using spectra (or by combining photometry) to determine the physical parameters. We choose a sample of 17 star clusters in M33, which previously lacked spectroscopic observations. The low-resolution spectra were taken with the Xinglong 2.16 m reflector of NAOC. The photometry used in the fitting includes uSC and vSAGE bands from the SAGE survey, as well as the published UBVRI and ugriz photometry. We first derived ages and metallicities with the ULYSS (Vazdekis et al. and PEGASE-HR) simple stellar population model and the Bruzual &amp; Charlot stellar population synthesis models for the full-spectrum fitting. The fitting results of both the BC03 and ULYSS models seem consistent with those of previous works as well. Then, we add the SAGE uSC and vSAGE photometry in the spectroscopic fitting with the BC03 models. It seems that the results become much better, especially for the Padova 2000+Chabrier initial mass function set. Finally, we add more photometry data, UBVRI and ugriz, in the fitting, and we found that the results do not improve significantly. Therefore, we conclude that the photometry is useful for improving the fitting results, especially for the blue bands (λ &lt; 4000 Å), e.g., uSC and vSAGE band. At last, we discuss the "UV excess" for the star clusters, and we find that five star clusters have UV excess, based on the GALEX far-UV and near-UV photometry.

Keywords: Andromeda Galaxy, Sky surveys, Spectral energy distribution, Star clusters
CMZoom. II. Catalog of Compact Submillimeter Dust Continuum Sources in the Milky Way's Central Molecular Zone. In this paper we present the CMZoom survey's catalog of compact sources (&lt;10″, ∼0.4 pc) within the central molecular zone (CMZ). CMZoom is a Submillimeter Array large program designed to provide a complete and unbiased map of all high column density gas (N(H2) ≥ 1023 cm-2) of the innermost 500 pc of the Galaxy in the 1.3 mm dust continuum. We generate both a robust catalog designed to reduce spurious source detections, and a second catalog with higher completeness, both generated using a pruned dendrogram. In the robust catalog, we report 285 compact sources, or 816 in the high-completeness catalog. These sources have effective radii between 0.04 and 0.4 pc, and are the potential progenitors of star clusters. The masses for both catalogs are dominated by the Sagittarius B2 cloud complex, where masses are likely unreliable due to free-free contamination, uncertain dust temperatures, and line-of-sight confusion. Given the survey selection and completeness, we predict that our robust catalog accounts for more than ∼99% of compact substructure capable of forming high-mass stars in the CMZ. This catalog provides a crucial foundation for future studies of high-mass star formation in the Galactic Center.

Keywords: Galactic center, Infrared dark clouds, Star forming regions, Protostars, Molecular clouds, Dense interstellar clouds, Star formation, Submillimeter astronomy, Catalogs, Interferometry
Phase II of the LAMOST-Kepler/K2 Survey. I. Time Series of Medium-resolution Spectroscopic Observations. Phase II of the Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST)-Kepler/K2 survey (LK-MRS), initiated in 2018, aims at collecting medium-resolution spectra (R ∼ 7500; hereafter MRS) for more than 50,000 stars with multiple visits (∼60 epochs) over a period of 5 yr (2018 September to 2023 June). We selected 20 footprints distributed across the Kepler field and six K2 campaigns, with each plate containing a number of stars ranging from ∼2000 to ∼3000. During the first year of observations, the LK-MRS has already visited 13 plates 223 times over 40 individual nights, and collected ∼280,000 and ∼369,000 high-quality spectra in the blue and red wavelength ranges, respectively. The atmospheric parameters and radial velocities for ∼259,000 spectra of 21,053 targets were successfully calculated by the LAMOST stellar parameter pipeline. The internal uncertainties for the effective temperature, surface gravity, metallicity, and radial velocity are found to be 100 K, 0.15 dex, 0.09 dex, and 1.00 km s-1, respectively, when derived from a medium-resolution LAMOST spectrum with a signal-to-noise ratio (S/N) in the g band of 10. All of the uncertainties decrease as S/N increases, but they stabilize for S/N &gt; 100. We found 14,997, 20,091, and 1514 stars in common with the targets from the LAMOST low-resolution survey (LRS), Gaia, and the Apache Point Observatory Galactic Evolution Experiment (APOGEE), respectively, corresponding to fractions of ∼70%, ∼95%, and ∼7.2%. In general, the parameters derived from LK-MRS spectra are consistent with those obtained from the LRS and APOGEE spectra, but the scatter increases as the surface gravity decreases when comparing with the measurements from APOGEE. A large discrepancy is found with the Gaia values of the effective temperature. Comparisons of the radial velocities of LK-MRS to Gaia and LK-MRS to APOGEE nearly follow a Gaussian distribution with means of μ ∼ 1.10 and 0.73 km s-1, respectively. We expect that the results from the LK-MRS spectra will shed new light on binary stars, asteroseismology, stellar activity, and other research fields.

Keywords: Astronomy databases, Surveys, Fundamental parameters of stars, Astrostatistics, Spectroscopy, Catalogs
The Splashback Radius of Halos from Particle Dynamics. III. Halo Catalogs, Merger Trees, and Host-Subhalo Relations. Virtually any investigation involving dark matter halos relies on a definition of their radius, of their mass, and of whether they are a subhalo. The halo boundary is most commonly defined to include a spherical overdensity contrast (such as ${R}_{200{\rm{c}}}$ , ${R}_{\mathrm{vir}}$ , and ${R}_{200{\rm{m}}}$ ), but different thresholds lead to significant differences in radius and mass. The splashback radius has recently been suggested as a more physically motivated (and generally larger) halo boundary, adding to the range of definitions. It is often difficult to assess the impact of a particular choice because most halo catalogs contain only one or a few definitions and generally only one set of host-subhalo relations. To alleviate this issue, we present halo catalogs and merger trees for 14 N-body simulations of ΛCDM and self-similar universes. Based on ROCKSTAR catalogs, we compute additional halo properties using the SPARTA code and recombine them with the original catalogs. The new catalogs contain numerous variants of spherical overdensity and splashback radii and masses and, most critically, host-subhalo relations for each definition. We also present a new merger tree format where the data are stored as a compressed, two-dimensional matrix. We perform basic tests of the relation between different definitions and present an updated model for the splashback-spherical overdensity connection. The SPARTA code, as well as our catalogs and merger trees, are publicly available.

Keywords: Dark matter, Large-scale structure of the universe
Dippers from the TESS Full-frame Images. I. Results of the First One Year Data and Discovery of a Runaway Dipper. We present a comprehensive catalog of the dippers—young stellar objects that exhibit episodic dimming—derived from one year's worth of data of the Transiting Exoplanet Survey Satellite (TESS) full-frame images. In the survey, we found 35 dippers using the convolutional neural network, most of them newly discovered. Although these dippers are widely distributed over the first half-hemisphere that TESS surveyed, we identified the majority's membership with the nearest association Scorpius-Centaurus, Velorum OB2, and the nearby Orion molecular cloud complex. However, several dippers are likely to be located in the field. We also found three old dippers whose age exceeds 10 million years, which is considered to be the disk dissipation time. The color-color diagram indicates that these old dippers are likely to have an extreme debris disk. In particular, we found a runaway old dipper having a large three-dimensional velocity of 72 km s-1. The dippers in the field, which were probably escaping from their birth molecular clouds or were born outside the current area of star-forming regions, are more common than previously considered.

Keywords: T Tauri stars, Protoplanetary disks, Variable stars
FPFS Shear Estimator: Systematic Tests on the Hyper Suprime-Cam Survey First-year Data. We apply the Fourier Power Function Shapelets (FPFS) shear estimator to the first-year data of the Hyper Suprime-Cam survey to construct a shape catalog. The FPFS shear estimator has been demonstrated to have a multiplicative bias less than 1% in the absence of blending, regardless of complexities of galaxy shapes, smears of point spread functions (PSFs), and contamination from noise. The blending bias is calibrated with realistic image simulations, which include the impact of neighboring objects, using the COSMOS Hubble Space Telescope images. Here we carefully test the influence of PSF model residual on the FPFS shear estimation and the uncertainties in the shear calibration. Internal null tests are conducted to characterize potential systematics in the FPFS shape catalog, and the results are compared with those measured using a catalog where the shapes were estimated using the re-Gaussianization algorithms. Furthermore, we compare various weak-lensing measurements between the FPFS shape catalog and the re-Gaussianization shape catalog and conclude that the weak-lensing measurements between these two shape catalogs are consistent with each other within the statistical uncertainty.

Keywords: Weak gravitational lensing, Observational cosmology, Astronomy data analysis
ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP). II. Survey Overview: A First Look at 1.3 mm Continuum Maps and Molecular Outflows. Planck Galactic Cold Clumps (PGCCs) are considered to be the ideal targets to probe the early phases of star formation. We have conducted a survey of 72 young dense cores inside PGCCs in the Orion complex with the Atacama Large Millimeter/submillimeter Array (ALMA) at 1.3 mm (band 6) using three different configurations (resolutions ∼0"35, 1"0, and 7"0) to statistically investigate their evolutionary stages and substructures. We have obtained images of the 1.3 mm continuum and molecular line emission (12CO, and SiO) at an angular resolution of ∼0"35 (∼140 au) with the combined arrays. We find 70 substructures within 48 detected dense cores with median dust mass ∼0.093 M⊙ and deconvolved size ∼0"27. Dense substructures are clearly detected within the central 1000 au of four candidate prestellar cores. The sizes and masses of the substructures in continuum emission are found to be significantly reduced with protostellar evolution from Class 0 to Class I. We also study the evolutionary change in the outflow characteristics through the course of protostellar mass accretion. A total of 37 sources exhibit CO outflows, and 20 (&gt;50%) show high-velocity jets in SiO. The CO velocity extents (ΔVs) span from 4 to 110 km s-1 with outflow cavity opening angle width at 400 au ranging from [Θobs]400 ∼ 0"6-3"9, which corresponds to 33°4-125°7. For the majority of the outflow sources, the ΔVs show a positive correlation with [Θobs]400, suggesting that as protostars undergo gravitational collapse, the cavity opening of a protostellar outflow widens and the protostars possibly generate more energetic outflows.

Keywords: Early stellar evolution, Stellar abundances, Star forming regions, Stellar jets, Astrochemistry, Dense interstellar clouds, Stellar winds, Star formation, Low mass stars, Spectral energy distribution, Interstellar medium, Protostars
Renormalization Group Analysis of the Turbulent Hydromagnetic Dynamo: The Effect of Nonstationarity. The turbulent hydromagnetic dynamo is a process of magnetic field generation by chaotic flow of an electrically conducting fluid (plasma, liquid iron, etc.). It is responsible for generation of large-scale magnetic fields of astrophysical objects such as planets, stars, accretion disks, galaxies, galaxy clusters, etc. In particular, the dynamical process of induction of large-scale fields by highly conducting plasma has been very difficult to understand, as very low resistivity is not capable of creating a phase shift between magnetic and kinetic components of waves, making their interaction ineffective for generation of a large-scale electromotive force (EMF). The aim of the analysis presented here is to demonstrate that when the typically invoked statistical stationarity of turbulence is relaxed, large-scale magnetic fields can be very effectively generated by low-resistivity plasma. The renormalization group technique is applied to extract the final expression for the mean EMF from the fully nonlinear dynamical equations (Navier-Stokes, induction equation), and the mean field equations are solved for a force-free mode. Nonstationarity is shown to strongly enhance the process of large-scale EMF generation via wave interactions, and the dynamo effect induced by nonstationarity is proved to be effective. The results are also used to demonstrate the influence of magnetic fields and nonstationarity on energy and helicity spectra of turbulent flows.

Keywords: Galaxy magnetic fields, Magnetohydrodynamics, Astrophysical magnetism, Cosmic magnetic fields theory, Astrophysical fluid dynamics
The NASA Ames PAH IR Spectroscopic Database: The Laboratory Spectra. The astronomical emission features, formerly known as the unidentified infrared bands, are now commonly ascribed to polycyclic aromatic hydrocarbons (PAHs). The laboratory experiments and computational modeling performed at NASA Ames Research Center generated a collection of PAH IR spectra that have been used to test and refine the PAH model. These data have been assembled into the NASA Ames PAH IR Spectroscopic Database (PAHdb). PAHdb's library of computed spectra, currently at version 3.20, contains data on more than 4000 species and the library of laboratory-measured spectra, currently at version 3.00, contains data on 84 species. The spectra can be perused and are available for download at www.astrochemistry.org/pahdb/. This paper introduces the library of laboratory-measured spectra. Although it has been part of PAHdb since its inception, the library of laboratory-measured spectra lacked a proper description in the literature. Here, the experimental methods used to obtain the data are described in detail, an overview of the contents of the experimental library is given, and specific tools developed to analyze and interpret astronomical spectra with the laboratory data are discussed. In addition, updates to the website, documentation and software tools since our last reporting are presented. Software tools to work with the spectroscopic libraries are being developed actively and are available at GitHub. Lastly, a comprehensive demonstration showing how the laboratory-measured data can be applied to explore absorption features in observations toward embedded sources is presented. This demonstration suggests that PAHs very likely contribute to interstellar absorption spectra associated with dense clouds and underscores the need for further IR spectroscopic studies of PAHs trapped in water ice.

Keywords: Interstellar dust, Polycyclic aromatic hydrocarbons, Astronomy databases, Laboratory astrophysics, Experimental techniques, Astronomy data analysis, Astrochemistry
The K2 Galactic Archaeology Program Data Release 2: Asteroseismic Results from Campaigns 4, 6, and 7. Studies of Galactic structure and evolution have benefited enormously from Gaia kinematic information, though additional, intrinsic stellar parameters like age are required to best constrain Galactic models. Asteroseismology is the most precise method of providing such information for field star populations en masse, but existing samples for the most part have been limited to a few narrow fields of view by the CoRoT and Kepler missions. In an effort to provide well-characterized stellar parameters across a wide range in Galactic position, we present the second data release of red giant asteroseismic parameters for the K2 Galactic Archaeology Program (GAP). We provide ${\nu }_{\max }$ and ${\rm{\Delta }}\nu $ based on six independent pipeline analyses; first-ascent red giant branch (RGB) and red clump (RC) evolutionary state classifications from machine learning; and ready-to-use radius and mass coefficients, κR and κM, which, when appropriately multiplied by a solar-scaled effective temperature factor, yield physical stellar radii and masses. In total, we report 4395 radius and mass coefficients, with typical uncertainties of 3.3% (stat.) ± 1% (syst.) for κR and 7.7% (stat.) ± 2% (syst.) for κM among RGB stars, and 5.0% (stat.) ± 1% (syst.) for κR and 10.5% (stat.) ± 2% (syst.) for κM among RC stars. We verify that the sample is nearly complete—except for a dearth of stars with ${\nu }_{\max }\lesssim 10\mbox{--}20\,\mu \mathrm{Hz}$ —by comparing to Galactic models and visual inspection. Our asteroseismic radii agree with radii derived from Gaia Data Release 2 parallaxes to within 2.2% ± 0.3% for RGB stars and 2.0% ± 0.6% for RC stars.

Keywords: Red giant branch, Red giant clump, Stellar radii, Stellar masses, Asteroseismology, Catalogs
Measurements of the Hyperfine Structure of Atomic Energy Levels in Co II. Analysis of hyperfine structure constants of singly ionized cobalt (Co II) were performed on cobalt spectra measured by Fourier transform spectrometers in the region 3000-63,000 cm-1 (33333 - 1587 Å). Fits to over 700 spectral lines led to measurements of 292 magnetic dipole hyperfine interaction A constants, with values between -32.5 mK and 59.5 mK (1 mK = 0.001 cm-1). Uncertainties of 255 A constants were between ±0.4 mK and ±3.0 mK, the remaining 37 ranged up to ±7 mK. The electric quadrupole hyperfine interaction B constant could be estimated for only one energy level. The number of Co II levels with known A values has now increased tenfold, improving and enabling the wider, more reliable, and accurate application of Co II in astronomical chemical abundance analyses.

Keywords: Line positions, Atomic physics, Laboratory astrophysics, Experimental techniques, Atomic spectroscopy, Spectroscopy, Line intensities
Legolas: A Modern Tool for Magnetohydrodynamic Spectroscopy. Magnetohydrodynamic (MHD) spectroscopy is central to many astrophysical disciplines, ranging from helio- to asteroseismology, over solar coronal (loop) seismology, to the study of waves and instabilities in jets, accretion disks, or solar/stellar atmospheres. MHD spectroscopy quantifies all linear (standing or traveling) wave modes, including overstable (i.e., growing) or damped modes, for a given configuration that achieves force and thermodynamic balance. Here, we present Legolas, a novel, open-source numerical code to calculate the full MHD spectrum of one-dimensional equilibria with flow, balancing pressure gradients, Lorentz forces, centrifugal effects, and gravity, and enriched with nonadiabatic aspects like radiative losses, thermal conduction, and resistivity. The governing equations use Fourier representations in the ignorable coordinates, and the set of linearized equations is discretized using finite elements in the important height or radial variation, handling Cartesian and cylindrical geometries using the same implementation. A weak Galerkin formulation results in a generalized (non-Hermitian) matrix eigenvalue problem, and linear algebraic algorithms calculate all eigenvalues and corresponding eigenvectors. We showcase a plethora of well-established results, ranging from p and g modes in magnetized, stratified atmospheres, over modes relevant for coronal loop seismology, thermal instabilities, and discrete overstable Alfvén modes related to solar prominences, to stability studies for astrophysical jet flows. We encounter (quasi-)Parker, (quasi-)interchange, current-driven, and Kelvin-Helmholtz instabilities, as well as nonideal quasi-modes, resistive tearing modes, up to magnetothermal instabilities. The use of high resolution sheds new light on previously calculated spectra, revealing interesting spectral regions that have yet to be investigated.

Keywords: Solar coronal waves, Magnetohydrodynamics, Alfven waves, Computational methods
CO Outflow Candidates toward the W3/4/5 Complex. II. Feedback from Candidate Outflows. To date, few studies have focused on protostellar outflow feedback at scales larger than several parsecs. To address this paucity of research, we investigate the effects of feedback from CO outflow candidates on their parent clouds over ∼110 deg2 toward the W3/4/5 complex and its surroundings. Our search identified 265 13CO clouds with radii being ∼0.04-17.12 pc. We estimate the turbulent support and potential disruptive effect of the outflow activities through analyzing physical properties of outflow candidates and their host clouds in terms of turbulence and gravitational binding energy. We find that (1) clouds of larger size might be less affected by feedback; (2) the possible scale break is ≳4.7 pc for both turbulent support and potential disruptive effect; (3) if outflows couple to dense gas where stars are forming, for clouds in the Perseus arm, a scale ≲0.2-0.4 pc is sufficient for the energy and momentum injected by outflow activity to maintain turbulence, while for clouds in the Local arm, the scale is ≲0.1-0.2 pc; and (4) for clouds in the Perseus arm, a scale ≲0.3-1.0 pc is needed for outflow activity to potentially disperse material away from the natal clouds, while for clouds in the Local arm, the scale is ≲0.2-0.6 pc. The strength of outflow activity may affect the values in points 3 and 4. Finally, we find that outflow feedback probably possesses the power to alter the line width-size relation.

Keywords: Jets, Interstellar dynamics, Star formation, Interstellar clouds