Sazuna/UAT_keywords huggingface dataset:
Shock Breakout in Dense Circumstellar Material with Application to PS1-13arp. Shock breakout (SBO), the first expected electromagnetic signature of a supernova (SN), can be an important probe of the progenitors of these explosions. Unfortunately, SBO is difficult to capture with current surveys due to its brief timescale (≲1 hr). However, SBO may be lengthened when dense circumstellar material (CSM) is present. Indeed, recent photometric modeling studies of SNe, as well as early spectroscopy, suggest that such dense CSM may be present more often than previously expected. If true, this should also affect the features of SBO. We present an exploration of the impact of such CSM interaction on the SBO width and luminosity using both analytic and numerical modeling, where we parameterize the CSM as a steady-state wind. We then compare this modeling to PS1-13arp, an SN that showed an early UV excess that has been argued to be SBO in dense CSM. We find PS1-13arp is well fit with a wind of mass ∼0.08 M⊙ and radius ∼1900 R⊙, parameters which are similar to, if not slightly less massive than, what have been inferred for Type II SNe using photometric modeling. This similarity suggests that future SBO observations of SNe II may be easier to obtain than previously appreciated.

Keywords: Supernovae, Radiative transfer
A Machine-learning Approach to Integral Field Unit Spectroscopy Observations. II. H II Region Line Ratios. In the first paper of this series, we demonstrated that neural networks can robustly and efficiently estimate kinematic parameters for optical emission-line spectra taken by SITELLE at the Canada-France-Hawaii Telescope. This paper expands upon this notion by developing an artificial neural network to estimate the line ratios of strong emission lines present in the SN1, SN2, and SN3 filters of SITELLE. We construct a set of 50,000 synthetic spectra using line ratios taken from the Mexican Million Model database replicating H II regions. Residual analysis of the network on the test set reveals the network's ability to apply tight constraints to the line ratios. We verified the network's efficacy by constructing an activation map, checking the [N II] doublet fixed ratio, and applying a standard k-fold cross-correlation. Additionally, we apply the network to SITELLE observations of M33; the residuals between the algorithm's estimates and values calculated using standard fitting methods show general agreement. Moreover, the neural network reduces the computational costs by two orders of magnitude. Although standard fitting routines do consistently well depending on the signal-to-noise ratio of the spectral features, the neural network can also excels at predictions in the low signal-to-noise regime within the controlled environment of the training set as well as on observed data when the source spectral properties are well constrained by models. These results reinforce the power of machine learning in spectral analysis.

Keywords: Neural networks, Galaxy dynamics, Interstellar dust extinction, Galaxy kinematics, Interstellar clouds, Interstellar medium, Circumgalactic medium, Galaxy spectroscopy
On the Stickiness of CO<SUB>2</SUB> and H<SUB>2</SUB>O Ice Particles. Laboratory experiments revealed that CO2 ice particles stick less efficiently than H2O ice particles, and there is an order of magnitude difference in the threshold velocity for sticking. However, the surface energies and elastic moduli of CO2 and H2O ices are comparable, and the reason why CO2 ice particles were poorly sticky compared to H2O ice particles was unclear. Here we investigate the effects of viscoelastic dissipation on the threshold velocity for sticking of ice particles using the viscoelastic contact model derived by Krijt et al. We find that the threshold velocity for the sticking of CO2 ice particles reported in experimental studies is comparable to that predicted for perfectly elastic spheres. In contrast, the threshold velocity for the sticking of H2O ice particles is an order of magnitude higher than that predicted for perfectly elastic spheres. Therefore, we conclude that the large difference in stickiness between CO2 and H2O ice particles would mainly originate from the difference in the strength of viscoelastic dissipation, which is controlled by the viscoelastic relaxation time.

Keywords: Solid matter physics, Astrochemistry, Protoplanetary disks, Circumstellar disks, Planet formation, Planetesimals
Molecular Gas Distribution Perpendicular to the Galactic Plane. We use the ∼370 deg2 data from the MWISP CO survey to study the vertical distribution of the molecular clouds (MCs) toward the tangent points in the region of l = [+16°, +52°] and ∣b∣ &lt; 5°1. We find that the molecular disk consists of two components with a layer thickness (FWHM) of ∼85 pc and ∼280 pc, respectively. In the inner Galaxy, the molecular mass in the thin disk is dominant, while the molecular mass traced by the discrete MCs with weak CO emission in the thick disk is probably ≲10% of the whole molecular disk. For the CO gas in the thick disk, we identified 1055 high-z MCs that are ≳100 pc from the Galactic plane. However, only a few samples (i.e., 32 MCs or 3%) are located in the ∣z∣ ≳ 360 pc region. Typically, the discrete MCs of the thick-disk population have a median peak temperature of 2.1 K, a median velocity dispersion of 0.8 km s-1, and a median effective radius of 2.5 pc. Assuming a constant value of XCO = 2 × 1020 cm-2(K km s-1)-1, the median surface density of these MCs is 6.8 M⊙ pc-2, indicating very faint CO emission for the high-z gas. The cloud-cloud velocity dispersion is 4.9 ± 1.3 km s-1 and a linear variation with a slope of ∼-0.4 km s-1 kpc-1 is obtained in the region of RGC = 2.2-6.4 kpc. Assuming that these clouds are supported by their turbulent motions against the gravitational pull of the disk, a model of ρ0(R) = 1.28 M⊙ pc-3 ${e}^{-\displaystyle \frac{R}{3.2\mathrm{kpc}}}$ &lt;!-- --&gt; can be used to describe the distribution of the total mass density in the Galactic midplane.

Keywords: Stellar-interstellar interactions, Interstellar dynamics, Surveys, Molecular clouds, Milky Way disk, Interstellar medium
Census of R Coronae Borealis Stars. I. Infrared Light Curves from Palomar Gattini IR. We are undertaking the first systematic infrared (IR) census of R Coronae Borealis (RCB) stars in the Milky Way, beginning with IR light curves from the Palomar Gattini IR (PGIR) survey. The PGIR is a 30 cm J-band telescope with a 25 deg2 camera that is surveying 18,000 deg2 of the northern sky (δ &gt; -28°) at a cadence of 2 days. We present PGIR light curves for 922 RCB candidates selected from a mid-IR color-based catalog. Of these 922, 149 are promising RCB candidates, as they show pulsations or declines similar to RCB stars. The majority of the candidates that are not RCB stars are either long-period variables (LPVs) or RV Tauri stars. We identify IR color-based criteria to better distinguish between RCB stars and LPVs. As part of a pilot spectroscopic run, we obtain NIR spectra for 26 of the 149 promising candidates and spectroscopically confirm 11 new RCB stars. We detect strong He I λ10830 features in the spectra of all RCB stars, likely originating within high-velocity (200-400 km s-1) winds in their atmospheres. Nine of these RCB stars show 12C16O and 12C18O molecular absorption features, suggesting that they are formed through a white dwarf merger. We detect quasiperiodic pulsations in the light curves of five RCB stars. The periods range between 30 and 125 days and likely originate from the strange-mode instability in these stars. Our pilot run results motivate a dedicated IR spectroscopic campaign to classify all RCB candidates.

Keywords: R Coronae Borealis variable stars, Hydrogen deficient stars, Time domain astronomy, Near infrared astronomy
Discovery and Characterization of a Rare Magnetic Hybrid β Cephei Slowly Pulsating B-type Star in an Eclipsing Binary in the Young Open Cluster NGC 6193. As many as 10% of OB-type stars have global magnetic fields, which is surprising given that their internal structure is radiative near the surface. A direct probe of internal structure is pulsations, and some OB-type stars exhibit pressure modes (β Cep pulsators) or gravity modes (slowly pulsating B-type stars; SPBs); a few rare cases of hybrid β Cep/SPBs occupy a narrow instability strip in the H-R diagram. The most precise fundamental properties of stars are obtained from eclipsing binaries (EBs), and those in clusters with known ages and metallicities provide the most stringent constraints on theory. Here we report the discovery that HD 149834 in the ∼5 Myr cluster NGC 6193 is an EB comprising a hybrid β Cep/SPB pulsator and a highly irradiated low-mass companion. We determine the masses, radii, and temperatures of both stars; the ∼9.7 M⊙ primary resides in the instability strip where hybrid pulsations are theoretically predicted. The presence of both SPB and β Cep pulsations indicates that the system has a near-solar metallicity, and is in the second half of the main-sequence lifetime. The radius of the ∼1.2 M⊙ companion is consistent with theoretical pre-main-sequence isochrones at 5 Myr, but its temperature is much higher than expected, perhaps due to irradiation by the primary. The radius of the primary is larger than expected, unless its metallicity is super-solar. Finally, the light curve shows residual modulation consistent with the rotation of the primary, and Chandra observations reveal a flare, both of which suggest the presence of starspots and thus magnetism on the primary.

Keywords: Pulsating variable stars, Beta Cephei variable stars, Young star clusters, Eclipsing binary stars, Double-mode variable stars
Surveying the X-Ray Behavior of Novae as They Emit γ-Rays. The detection of GeV γ-ray emission from Galactic novae by the Fermi-Large Area Telescope has become routine since 2010, and is generally associated with shocks internal to the nova ejecta. These shocks are also expected to heat plasma to ∼107 K, resulting in detectable X-ray emission. In this paper, we investigate 13 γ-ray emitting novae observed with the Neil Gehrels Swift Observatory, searching for 1-10 keV X-ray emission concurrent with γ-ray detections. We also analyze γ-ray observations of novae V407 Lup (2016) and V357 Mus (2018). We find that most novae do eventually show X-ray evidence of hot shocked plasma, but not until the γ-rays have faded below detectability. We suggest that the delayed rise of the X-ray emission is due to large absorbing columns and/or X-ray suppression by corrugated shock fronts. The only nova in our sample with a concurrent X-ray/γ-ray detection is also the only embedded nova (V407 Cyg). This exception supports a scenario where novae with giant companions produce shocks with external circumbinary material and are characterized by lower density environments, in comparison with novae with dwarf companions where shocks occur internal to the dense ejecta.

Keywords: X-ray astronomy, Observational astronomy, High energy astrophysics, Symbiotic binary stars, White dwarf stars, Shocks, Novae, Gamma-ray astronomy, Cataclysmic variable stars, Gamma-ray transient sources, Classical novae
RELICS: Properties of z ≥ 5.5 Galaxies Inferred from Spitzer and Hubble Imaging, Including A Candidate z ∼ 6.8 Strong [O III] emitter. We present constraints on the physical properties (including stellar mass, age, and star formation rate) of 207 6 ≲ z ≲ 8 galaxy candidates from the Reionization Lensing Cluster Survey (RELICS) and Spitzer-RELICS surveys. We measure photometry using T-PHOT and perform spectral energy distribution fitting using EAzY and BAGPIPES. Of the 207 candidates for which we could successfully measure (or place limits on) Spitzer fluxes, 23 were demoted to likely z &lt; 4. Among the high-z candidates, we find intrinsic stellar masses between 1 × 106M☉ and 4 × 109M☉, and rest-frame UV absolute magnitudes between -22.6 and -14.5 mag. While our sample is mostly comprised of ${L}_{m\mathrm{UV}}/{L}_{m\mathrm{UV}}^{* }\lt 1$ &lt;!-- --&gt; galaxies, it extends to ${L}_{m\mathrm{UV}}/{L}_{m\mathrm{UV}}^{* }\sim 2$ &lt;!-- --&gt; . Our sample spans ∼4 orders of magnitude in stellar mass and star formation rates, and exhibits ages that range from maximally young to maximally old. We highlight 11 z ≥ 6.5 galaxies with detections in Spitzer/IRAC imaging, several of which show evidence for some combination of evolved stellar populations, large contributions of nebular emission lines, and/or dust. Among these is PLCKG287+32-2013, one of the brightest z ∼ 7 candidates known (AB mag 24.9 at 1.6 μm) with a Spitzer 3.6 μm flux excess suggesting strong [O III] + H-β emission (∼1000 Å rest-frame equivalent width). We discuss the possible uses and limits of our sample and present a public catalog of Hubble + Spitzer photometry along with physical property estimates for all objects in the sample. Because of their apparent brightnesses, high redshifts, and variety of stellar populations, these objects are excellent targets for follow-up with the James Webb Space Telescope.

Keywords: High-redshift galaxies, Galaxies
Galactic Cosmic Rays, Cosmic-Ray Variations, and Cosmogenic Nuclides in Meteorites. We present a new generation of model calculations for cosmogenic production rates in various types of solar system bodies. The model is based on the spectra for primary and secondary particles calculated using the INCL++6 code, which is the most reliable and most sophisticated code available for spallation reactions. Thanks to the recent improvements (extending the code to lower and higher energies and considering light charged particles as ejectiles and projectiles), we can for the first time directly consider primary and secondary Galactic α particles. We calculate production rates for 22Na, 10Be, and 26Al in an L-chondrite with a radius of 45 cm and in the Apollo 15 drill core, and we determine the long-term average Galactic cosmic-ray (GCR) spectrum (represented by the solar modulation potential Φ) in the meteoroid orbits at ∼3 au of Φ = 600 MV and at 1 au, i.e., for Earth and Moon of Φ = 660 MV. From this, we calculate a long-term average GCR gradient in the inner solar system of ∼5% au-1. Finally, we discuss the possibility of studying temporal GCR variations and meteoroid orbits using production rate ratios of short- and long-lived radionuclides.

Keywords: Galactic cosmic rays, Meteorites, The Moon, Heliosphere
Gas-phase Metallicity as a Diagnostic of the Drivers of Star Formation on Different Spatial Scales. We examine the correlations of star formation rate (SFR) and gas-phase metallicity Z. We first predict how the SFR, cold gas mass, and Z will change with variations in inflow rate or in star formation efficiency (SFE) in a simple gas-regulator framework. The changes ${\rm{\Delta }}\mathrm{log}$ &lt;!-- --&gt; SFR and ${\rm{\Delta }}\mathrm{log}Z$ &lt;!-- --&gt; are found to be negatively (positively) correlated when driving the gas regulator with time-varying inflow rate (SFE). We then study the correlation of ${\rm{\Delta }}\mathrm{log}$ &lt;!-- --&gt; sSFR (specific SFR) and ${\rm{\Delta }}\mathrm{log}$ &lt;!-- --&gt; (O/H) from observations, at both ∼100 pc and galactic scales, based on two two-dimensional spectroscopic surveys with different spatial resolutions, MAD and MaNGA. After taking out the overall mass and radial dependences, which may reflect changes in inflow gas metallicity and/or outflow mass loading, we find that ${\rm{\Delta }}\mathrm{log}$ &lt;!-- --&gt; sSFR and ${\rm{\Delta }}\mathrm{log}$ &lt;!-- --&gt; (O/H) on galactic scales are found to be negatively correlated, but ${\rm{\Delta }}\mathrm{log}$ &lt;!-- --&gt; sSFR and ${\rm{\Delta }}\mathrm{log}$ &lt;!-- --&gt; (O/H) are positively correlated on ∼100 pc scales within galaxies. If we assume that the variations across the population reflect temporal variations in individual objects, we conclude that variations in the SFR are primarily driven by time-varying inflow at galactic scales and driven by time-varying SFE at ∼100 pc scales. We build a theoretical framework to understand the correlation between SFR, gas mass, and metallicity, as well as their variability, which potentially uncovers the relevant physical processes of star formation at different scales.

Keywords: Metallicity, Star formation, Galaxy evolution, Galaxy chemical evolution
Relation between Quiescence and Outbursting Properties of GX 339-4. Galactic black hole candidate GX 339-4 underwent several outbursting phases in the past two and a half decades at irregular intervals of 2-3 years. The nature of these outbursts in terms of the duration, number of peaks, maximum peak intensity, and so on varies. We present a possible physical reason behind the variation of the outbursts. From a physical point of view, if the supply of matter from the companion is roughly constant, the total energy released in an outburst is expected to be proportional to the quiescent period prior to the outburst when the matter is accumulated. We use archival data of RXTE/ASM from 1996 January to 2011 June and of MAXI/GSC from 2009 August to 2020 July. Five initial outbursts of GX 339-4 between 1997 and 2011 were observed by ASM and showed a good linear relation between the accumulation period and the amount of energy released in each outburst, but the outbursts after 2013 behaved quite differently. The 2013, 2017-2018, and 2018-2019 outbursts were of short duration and incomplete or "failed" in nature. We suggest that the matter accumulated during the quiescent periods prior to these outbursts was not cleared through accretion due to a lack of viscosity. The leftover matter was cleared in the very next outbursts. Our study thus sheds light on long-term accretion dynamics in outbursting sources.

Keywords: Accretion, Black hole physics, X-ray binary stars, Black holes, X-ray transient sources
Quantifying Feedback from Narrow Line Region Outflows in Nearby Active Galaxies. III. Results for the Seyfert 2 Galaxies Markarian 3, Markarian 78, and NGC 1068. Outflows of ionized gas driven by active galactic nuclei (AGN) may significantly impact the evolution of their host galaxies. However, determining the energetics of these outflows is difficult with spatially unresolved observations that are subject to strong global selection effects. We present part of an ongoing study using Hubble Space Telescope and Apache Point Observatory spectroscopy and imaging to derive spatially resolved mass outflow rates and energetics for narrow-line region outflows in nearby AGN that are based on multi-component photoionization models to account for spatial variations in gas ionization, density, abundances, and dust content. This expanded analysis adds Mrk 3, Mrk 78, and NGC 1068, doubling our earlier sample. We find that the outflows contain total ionized gas masses of M ≈ 105.5-107.5 M⊙ and reach peak velocities of v ≈ 800-2000 km s-1. The outflows reach maximum mass outflow rates of ${\dot{M}}_{\mathrm{out}}\approx 3\mbox{--}12\,{M}_{\odot }$ &lt;!-- --&gt; yr-1 and encompass total kinetic energies of E ≈ 1054-1056 erg. The outflows extend to radial distances of r ≈ 0.1-3 kpc from the nucleus, with the gas masses, outflow energetics, and radial extents positively correlated with AGN luminosity. The outflow rates are consistent with in situ ionization and acceleration where gas is radiatively driven at multiple radii. These radial variations indicate that spatially resolved observations are essential for localizing AGN feedback and determining the most accurate outflow parameters. * Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program Nos. 5140, 5754, 7404, 7573, and 8480. † Based in part on observations obtained with the Apache Point Observatory 3.5 m telescope, which is owned and operated by the Astrophysical Research Consortium.

Keywords: AGN host galaxies, Supermassive black holes, Markarian galaxies, Active galaxies, Emission line galaxies, Seyfert galaxies, Active galactic nuclei, Galaxy kinematics, Galaxy winds, Interstellar medium wind
Anomalous Proton Velocity Diffusion by Quasi-monochromatic Kinetic Alfvén Waves. The anomalous diffusion of resonant protons in parallel and perpendicular velocity space by kinetic Alfvén waves is discussed. The velocity diffusion coefficient is calculated by employing an autocorrelation function for proton trajectories. It is found that for protons resonant with the waves, the perpendicular diffusion coefficient decays away for a sufficiently long time, but parallel diffusion monotonically increases in time until it saturates at a certain level. This result indicates that a portion of resonant protons can undergo anomalous diffusion along the background magnetic field even if the intensity of the kinetic Alfvén wave is sufficiently low. The present findings imply that under suitable conditions, astrophysical charged-particle acceleration can take place in the parallel direction.

Keywords: Solar magnetic fields
Carbon-chain Chemistry versus Complex-organic-molecule Chemistry in Envelopes around Three Low-mass Young Stellar Objects in the Perseus Region. We have analyzed ALMA Cycle 5 data in Band 4 toward three low-mass young stellar objects, IRAS 03235+3004 (hereafter IRAS 03235), IRAS 03245+3002 (IRAS 03245), and IRAS 03271+3013 (IRAS 03271), in the Perseus region. The HC3N (J = 16-15; Eup/k = 59.4 K) line has been detected in all of the target sources, while four CH3OH lines (Eup/k = 15.4-36.3 K) have been detected only in IRAS 03245. Sizes of the HC3N distributions (∼2930-3230 au) in IRAS 03235 and IRAS 03245 are similar to those of the carbon-chain species in the warm carbon-chain chemistry (WCCC) source L1527. The size of the CH3OH emission in IRAS 03245 is ∼1760 au, which is slightly smaller than that of HC3N in this source. We compare the CH3OH/HC3N abundance ratios observed in these sources with predictions of chemical models. We confirm that the observed ratio in IRAS 03245 agrees with the modeled values at temperatures around 30-35 K, which supports the HC3N formation by the WCCC mechanism. In this temperature range, CH3OH does not thermally desorb from dust grains. Nonthermal desorption mechanisms or gas-phase formation of CH3OH seem to work efficiently around IRAS 03245. The fact that IRAS 03245 has the highest bolometric luminosity among the target sources seems to support these mechanisms, in particular the nonthermal desorption mechanisms.

Keywords: Interstellar molecules, Low mass stars, Astrochemistry
Angular Distribution and Polarization of the 3C and 3D Lines Following Electron-impact Excitation of Fe<SUP>16+</SUP> Ions. The electron-impact excitations from the ground state to the excited levels $1{s}^{2}2{s}^{2}2{p}_{1/2}^{5}3{d}_{3/2}\,J=1$ &lt;!-- --&gt; and $1{s}^{2}2{s}^{2}2{p}_{3/2}^{5}3{d}_{5/2}\,J=1$ &lt;!-- --&gt; as well as the subsequent radiative decays of neonlike Fe16+ ions have been investigated within the framework of the multiconfigurational Dirac-Fock method and the relativistic distorted-wave theory. Special attention has been paid to emission behaviors of the astrophysically relevant resonance 3C and intercombination 3D lines emitted in the radiative decays of Fe16+ ions. To this end, we calculate the angular distribution and linear polarization of both of the lines for a series of impact electron energies. It is found that the angular and polarization behaviors of the resonance 3C line are nearly the same as those of the intercombination 3D line. Nevertheless, the angular and polarization behaviors of both of the lines are found to be very sensitive to the impact electron energy, especially at low impact energies. Based on such a sensitivity, it is expected that high-precision angular and polarization measurements of the 3C and 3D lines could be served as a tool for revealing detailed information such as electron energy of relevant laboratory and astrophysical plasmas.

Keywords: Theoretical models, Atomic physics, Collision physics, Atomic spectroscopy, Radiative processes