Sazuna/UAT_keywords huggingface dataset:
A Detailed Analysis of the Cloud Structure and Dynamics in Aquila Rift. We present maps in several molecular emission lines of a 1 square degree region covering the W40 and Serpens South molecular clouds belonging to the Aquila Rift complex. The observations were made with the 45 m telescope at the Nobeyama Radio Observatory. We found that the 12CO and 13CO emission lines consist of several velocity components with different spatial distributions. The component that forms the main cloud of W40 and Serpens South, which we call the "main component," has a velocity of VLSR ≃ 7 km s-1. There is another significant component at VLSR ≃ 40 km s-1, which we call the "40 km s-1 component." The latter component is mainly distributed around two young clusters: W40 and Serpens South. Moreover, the two components look spatially anticorrelated. Such spatial configuration suggests that the star formation in W40 and Serpens South was induced by the collision of the two components. We also discuss a possibility that the 40 km s-1 component consists of gas swept up by superbubbles created by SNRs and stellar winds from the Scorpius-Centaurus association.

Keywords: H II regions, Molecular clouds, Interstellar medium
New Type Ia Supernova Yields and the Manganese and Nickel Problems in the Milky Way and Dwarf Spheroidal Galaxies. In our quest to identify the progenitors of Type Ia supernovae (SNe Ia), we first update the nucleosynthesis yields for both near-Chandrasekhar- (Ch) and sub-Ch-mass white dwarfs (WDs) for a wide range of metallicities with our 2D hydrodynamical code and the latest nuclear reaction rates. We then include the yields in our galactic chemical evolution code to predict the evolution of elemental abundances in the solar neighborhood and dwarf spheroidal (dSph) galaxies Fornax, Sculptor, Sextans, and Carina. In the observations of the solar neighborhood stars, Mn shows an opposite trend to α elements, showing an increase toward higher metallicities, which is very well reproduced by the deflagration-detonation transition of Ch-mass WDs but never by double detonations of sub-Ch-mass WDs alone. The problem of Ch-mass SNe Ia was the Ni overproduction at high metallicities. However, we found that Ni yields of Ch-mass SNe Ia are much lower with the solar-scaled initial composition than in previous works, which keeps the predicted Ni abundance within the observational scatter. From the evolutionary trends of elemental abundances in the solar neighborhood, we conclude that the contribution of sub-Ch-mass SNe Ia to chemical enrichment is up to 25%. In dSph galaxies, however, larger enrichment from sub-Ch-mass SNe Ia than in the solar neighborhood may be required, which causes a decrease in [(Mg, Cr, Mn, Ni)/Fe] at lower metallicities. The observed high [Mn/Fe] ratios in Sculptor and Carina may also require additional enrichment from pure deflagrations, possibly as SNe Iax. Future observations of dSph stars will provide more stringent constraints on the progenitor systems and explosion mechanism of SNe Ia.

Keywords: Explosive nucleosynthesis, Nucleosynthesis, Galaxy chemical evolution, Chemical abundances, Type Ia supernovae, Dwarf spheroidal galaxies, Fornax dwarf spheroidal galaxy, Supernovae, Sculptor dwarf elliptical galaxy
Kinematic Decomposition of IllustrisTNG Disk Galaxies: Morphology and Relation with Morphological Structures. We recently developed an automated method, auto-GMM, to decompose simulated galaxies. It extracts kinematic structures in an accurate, efficient, and unsupervised way. We use auto-GMM to study the stellar kinematic structures of disk galaxies from the TNG100 run of IllustrisTNG. We identify four to five structures that are commonly present among the diverse galaxy population. Structures having strong to moderate rotation are defined as cold and warm disks, respectively. Spheroidal structures dominated by random motions are classified as bulges or stellar halos, depending on how tightly bound they are. Disky bulges are structures that have moderate rotation but compact morphology. Across all disky galaxies and accounting for the stellar mass within 3 half-mass radii, the kinematic spheroidal structures, obtained by summing up stars of bulges and halos, contribute ∼45% of the total stellar mass, while the disky structures constitute ∼55%. This study also provides important insights into the relationship between kinematically and morphologically derived galactic structures. Comparing the morphology of kinematic structures with that of traditional bulge+disk decomposition, we conclude that (1) the morphologically decomposed bulges are composite structures comprising a slowly rotating bulge, an inner halo, and a disky bulge; (2) kinematically disky bulges, akin to what are commonly called pseudo-bulges in observations, are compact disk-like components that have rotation similar to warm disks; (3) halos contribute almost 30% of the surface density of the outer part of morphological disks when viewed face on; and (4) both cold and warm disks are often truncated in central regions.

Keywords: Hydrodynamical simulations, Disk galaxies, Galaxy dynamics, Galaxy structure, Galaxy kinematics
EvryFlare. II. Rotation Periods of the Cool Flare Stars in TESS across Half the Southern Sky. We measure rotation periods and sinusoidal amplitudes in Evryscope light curves for 122 two-minute K5-M4 TESS targets selected for strong flaring. The Evryscope array of telescopes has observed all bright nearby stars in the south, producing 2-minute cadence light curves since 2016. Long-term, high-cadence observations of rotating flare stars probe the complex relationship between stellar rotation, starspots, and superflares. We detect periods from 0.3487 to 104 days and observe amplitudes from 0.008 to 0.216 g' mag. We find that the Evryscope amplitudes are larger than those in TESS with the effect correlated to stellar mass (p-value = 0.01). We compute the Rossby number (Ro) and find that our sample selected for flaring has twice as many intermediate rotators (0.04 &lt; Ro &lt; 0.4) as fast (Ro &lt; 0.04) or slow (Ro &gt; 0.44) rotators; this may be astrophysical or a result of period detection sensitivity. We discover 30 fast, 59 intermediate, and 33 slow rotators. We measure a median starspot coverage of 13% of the stellar hemisphere and constrain the minimum magnetic field strength consistent with our flare energies and spot coverage to be 500 G, with later-type stars exhibiting lower values than earlier-type stars. We observe a possible change in superflare rates at intermediate periods. However, we do not conclusively confirm the increased activity of intermediate rotators seen in previous studies. We split all rotators at Ro ∼ 0.2 into bins of PRot &lt; 10 days and PRot &gt; 10 days to confirm that short-period rotators exhibit higher superflare rates, larger flare energies, and higher starspot coverage than do long-period rotators, at p-values of 3.2 × 10-5, 1.0 × 10-5, and 0.01, respectively.

Keywords: Starspots, Sky surveys, Optical flares, Stellar rotation, Time series analysis
Exoplanet Detection and Its Dependence on Stochastic Sampling of the Stellar Initial Mass Function. Young moving groups (YMGs) are close (&lt;100 pc), coherent collections of young (&lt;100 Myr) stars that appear to have formed in the same star-forming molecular cloud. As such we would expect their individual initial mass functions (IMFs) to be similar to other star-forming regions, and by extension the Galactic field. Their close proximity to the Sun and their young ages means that YMGs are promising locations to search for young forming exoplanets. However, due to their low numbers of stars, stochastic sampling of the IMF means their stellar populations could vary significantly. We determine the range of planet-hosting stars (spectral types A, G, and M) possible from sampling the IMF multiple times, and find that some YMGs appear deficient in M-dwarfs. We then use these data to show that the expected probability of detecting terrestrial magma ocean planets is highly dependent on the exact numbers of stars produced through stochastic sampling of the IMF.

Keywords: Extrasolar rocky planets, Stellar associations, Initial mass function, Planet formation
Magnetic Fields in the Early Stages of Massive Star Formation as Revealed by ALMA. We present 1.3 mm ALMA dust polarization observations at a resolution of ∼0.02 pc for three massive molecular clumps, MM1, MM4, and MM9, in the infrared dark cloud G28.34+0.06. With these sensitive and high-resolution continuum data, MM1 is resolved into a cluster of condensations. The magnetic field structure in each clump is revealed by the polarized emission. We found a trend of decreasing polarized emission fraction with increasing Stokes I intensities in MM1 and MM4. Using the angular dispersion function method (a modified Davis-Chandrasekhar-Fermi method), the plane-of-sky magnetic field strengths in two massive dense cores, MM1-Core1 and MM4-Core4, are estimated to be ∼1.6 mG and ∼0.32 mG, respectively. The virial parameters in MM1-Core1 and MM4-Core4 are calculated to be ∼0.76 and ∼0.37, respectively, suggesting that massive star formation does not start in equilibrium. Using the polarization-intensity gradient-local gravity method, we found that the local gravity is closely aligned with intensity gradient in the three clumps, and the magnetic field tends to be aligned with the local gravity in MM1 and MM4 except for regions near the emission peak, which suggests that the gravity plays a dominant role in regulating the gas collapse. Half of the outflows in MM4 and MM9 are found to be aligned within 10° of the condensation-scale (&lt;0.05 pc) magnetic field, indicating that the magnetic field could play an important role from condensation to disk scale in the early stage of massive star formation.

Keywords: Star formation, Polarimetry, Magnetic fields, Infrared dark clouds
Advection by Large-scale Spiral Flows in Galaxy Clusters. The intracluster medium of a galaxy cluster often shows an extended quasi-spiral structure, accentuated by tangential discontinuities known as cold fronts (CFs). These discontinuities are thought to isolate between low-entropy, high-metallicity gas inside (I.e., below) the CF that was lifted from the center of the cluster by some radial factor fI and high-entropy, low-metallicity gas outside the CF that was pushed inward by a factor fo. We find broad support for such a picture, by comparing the entropy and metallicity discontinuities with the respective azimuthal averages, using newly deprojected thermal profiles in clusters A2029, A2142, A2204, and Centaurus, supplemented by deprojected CFs from the literature. In particular, the mean advection factors fK and fZ, inferred from entropy and metallicity, respectively, strongly correlate ( ${ \mathcal R }={0.7}_{-0.3}^{+0.2}$ ) with each other, consistent with large-scale advection. However, unlike sloshing simulations, in which the inside/outside phases are an inflow/outflow settling back to equilibrium after a violent perturbation, our results are more consistent with an outflow/inflow, with the fast, Mach ${{ \mathcal M }}_{I}\sim 0.8$ gas inside the CF being a rapidly heated or mixed outflow, probably originating from the cD galaxy, and gas outside the CF being an ${{ \mathcal M }}_{o}\sim 0.03$ , slowly cooling inflow. In particular, entropy indicates an outside advection factor $1.3\,\lesssim $ fKo $\lesssim 1.5$ that is approximately constant in all CFs, gauging the distance traversed by inflowing gas within a cooling time. In contrast, $1.1\lesssim {f}_{{Ki}}\lesssim 2.5$ and $1\lesssim {f}_{Z}\lesssim 17$ vary considerably among clusters and strongly correlate ( $3.1\sigma {\rm{\mbox{--}}}4.2\sigma $ ) with the virial mass, ${f}_{{Ki}}\propto {M}_{200}^{0.14\pm 0.07}$ and ${f}_{Z}\propto {M}_{200}^{1.4\pm 0.4}$ , suggesting that each cluster sustains a quasi-steady spiral flow.

Keywords: Galaxy clusters, Intracluster medium, Cooling flows, X-ray astronomy
Role of the Coronal Environment in the Formation of Four Shocks Observed without Coronal Mass Ejections at Earth's Lagrangian Point L1. The main goal of this study is to determine the solar origin of four single shocks observed at the Lagrange point L1 and followed by storm sudden commencements (SSCs) during 2002. We look for associated coronal mass ejections (CMEs), starting from estimates of the transit time from Sun to Earth. For each CME, we investigate its association with a radio type II burst, an indicator of the presence of a shock wave. For three of the events, the type II burst is shown to propagate along the same, or a similar, direction as the fastest segment of the CME leading edge. We analyze for each event the role of the coronal environment in the CME development, the shock formation, and their propagation, to finally identify its complex evolution. The ballistic velocity of these shocks during their propagation from the corona to L1 is compared to the shock velocity at L1. Based on a detailed analysis of the shock propagation and possible interactions up to 30 solar radii, we find a coherent velocity evolution for each event, in particular for one event, the 2002 April 14 SSC, for which a previous study did not find a satisfactory CME source. For the other three events, we observe the formation of a white-light shock overlying the different sources associated with those events. The localization of the event sources over the poles, together with an origin of the shocks being due to encounters of CMEs, can explain why at L1 we observe only single shocks and not interplanetary CMEs.

Keywords: Solar coronal radio emission, Interplanetary shocks, Solar coronal mass ejections
WISEA J083011.95+283716.0: A Missing Link Planetary-mass Object. We present the discovery of WISEA J083011.95+283716.0, the first Y-dwarf candidate identified through the "Backyard Worlds: Planet 9" citizen science project. We identified this object as a red, fast-moving source with a faint W2 detection in multiepoch AllWISE and unWISE images. We have characterized this object with Spitzer and Hubble Space Telescope's (HST) follow-up imaging. With mid-infrared detections in Spitzer's ch1 and ch2 bands and flux upper limits in HST F105W and F125W filters, we find that this object is both very faint and has extremely red colors (ch1 - ch2 = 3.25 ± 0.23 mag, F125W - ch2 ≥ 9.36 mag), consistent with a Teff ∼ 300 K source, as estimated from the known Y-dwarf population. A preliminary parallax provides a distance of ${11.1}_{-1.5}^{+2.0}$ pc, leading to a slightly warmer temperature of ∼350 K. The extreme faintness and red HST and Spitzer colors of this object suggest that it may be a link between the broader Y-dwarf population and the coldest known brown dwarf WISE J0855-0714, and may highlight our limited knowledge of the true spread of Y-dwarf colors. We also present four additional "Backyard Worlds: Planet 9" late-T brown dwarf discoveries within 30 pc.

Keywords: Brown dwarfs, Parallax, Hubble Space Telescope, Y dwarfs, HST photometry, Infrared astronomy, Infrared telescopes, Infrared sources, Proper motions, Space telescopes, Infrared photometry, Near infrared astronomy
The Most Predictive Physical Properties for the Stellar Population Radial Profiles of Nearby Galaxies. We present a study on the radial profiles of the D4000, luminosity-weighted stellar ages τL, and luminosity-weighted stellar metallicities [Z/H]L of 3654 nearby galaxies (0.01 &lt; z &lt; 0.15) using the IFU spectroscopic data from the MaNGA survey available in the SDSS DR15, in an effort to explore the connection between median stellar population radial gradients (I.e., ∇D4000, ∇τL, ∇[Z/H]L) out to ∼1.5 Re and various galaxy properties, including stellar mass (M⋆), specific star formation rate (sSFR), morphologies, and local environment. We find that M⋆ is the single most predictive physical property for ∇D4000 and ∇[Z/H]L. The most predictive properties for ∇τL are sSFR and, to a lesser degree, M⋆. The environmental parameters, including local galaxy overdensities and central-satellite division, have virtually no correlation with stellar population radial profiles for the whole sample, but the ∇D4000 of star-forming satellite galaxies with M⋆ ≲ 1010 M⊙ exhibit a significant positive correlation with galaxy overdensities. Galaxies with lower sSFR have on average steeper negative stellar population gradients, and this sSFR dependence is stronger for more massive star-forming galaxies. The negative correlation between the median stellar population gradients and M⋆ are best described largely as segmented relationships, whereby median gradients of galaxies with log M⋆ ≲ 10.0 (with the exact value depending on sSFR) have much weaker mass dependence than galaxies with higher M⋆. While the dependence of the radial gradients of ages and metallicities on T-Types and central stellar mass surface densities are generally not significant, galaxies with later T-Types or lower central mass densities tend to have significantly lower D4000, younger τL, and lower [Z/H]L across the radial ranges probed in this study.

Keywords: Galaxy stellar content, Star formation, Galaxy evolution, Galaxies
Multiwavelength Observations of SDSS J105621.45+313822.1, a Broad-line, Low-metallicity AGN. In contrast to massive galaxies with solar or super-solar gas phase metallicities, very few active galactic nuclei (AGNs) are found in low-metallicity dwarf galaxies. Such a population could provide insight into the origins of supermassive black holes. Here we report near-IR spectroscopic and X-ray observations of SDSS J105621.45+313822.1, a low-mass, low-metallicity galaxy with optical narrow line ratios consistent with star-forming galaxies but a broad Hα line and mid-infrared colors consistent with an AGN. We detect the [Si VI] 1.96 μm coronal line and a broad Paα line with an FWHM of 850 ± 25 km s-1. Together with the optical broad lines and coronal lines seen in the Sloan Digital Sky Survey (SDSS) spectrum, we confirm the presence of a highly accreting black hole with mass (2.2 ± 1.3) × 106 M⊙, with a bolometric luminosity of ≈1044 erg s-1 based on the coronal line luminosity, implying a highly accreting AGN. Chandra observations reveal a weak nuclear point source with ${L}_{{\rm{X}},2\mbox{--}10\mathrm{keV}}=(2.3\pm 1.2)\times {10}^{41}$ erg s-1, ∼2 orders of magnitude lower than that predicted by the mid-infrared luminosity, suggesting that the AGN is highly obscured despite showing broad lines in the optical spectrum. The low X-ray luminosity and optical narrow line ratios of J1056+3138 highlight the limitations of commonly employed diagnostics in the hunt for AGNs in the low-metallicity, low-mass regime.

Keywords: AGN host galaxies, Supermassive black holes
Periodic Fast Radio Bursts as a Probe of Extragalactic Asteroid Belts. The periodic activity of the repeating fast radio burst (FRB) 180916.J0158+65 was recently reported by the CHIME/FRB Collaboration team. From this source 28 bursts not only show a ∼16 day period with an active phase of ∼4.0 days, but they also exhibit a broken power law in differential energy distribution. In this Letter, we suggest that FRB 180916.J0158+65-like periodic FRBs could provide a unique probe of extragalactic asteroid belts (EABs), based on our previously proposed pulsar-EAB impact model, in which repeating FRBs arise from an old-aged, slowly spinning, moderately magnetized pulsar traveling through an EAB around another stellar-mass object. These two objects form a binary, and thus the observed period is in fact the orbital period. We show that this model can be used to well interpret all of the observed data of FRB 180916.J0158+65. Furthermore, we constrain the EAB's physical properties and find that (1) the outer radius of the EAB is at least an order of magnitude smaller than that of its analog in the solar system, (2) the differential size distribution of the EAB's asteroids at small diameters (large diameters) is shallower (steeper) than that of solar system small objects, and (3) the two belts have a comparable mass.

Keywords: Neutron stars, Asteroids, Radio bursts, Radio continuum emission
Substructure Formation in a Protostellar Disk of L1527 IRS. We analyze multifrequency, high-resolution continuum data obtained by the Atacama Large Millimeter/submillimeter Array and the Jansky Very Lary Array to study the detailed structure of the dust distribution in the infant disk of a Class 0/I source, L1527 IRS. We find three clumps aligning in the north-south direction in the 7 mm radio continuum image. The three clumps remain even after subtracting free-free contamination, which is estimated from the 1.3 cm continuum observations. The northern and southern clumps are located at a distance of ∼15 au from the central clump and are likely optically thick at 7 mm wavelength. The clumps have similar integrated intensities. The symmetric physical properties could be realized when a dust ring, or spiral arms, around the central protostar is projected to the plane of the sky. We demonstrate for the first time that such substructure may form even in the disk-forming stage, where the surrounding materials actively accrete toward a disk-protostar system.

Keywords: Planetary system formation, Young stellar objects, Dust continuum emission, Star formation, Interstellar medium, Protostars, Circumstellar dust
Carnegie Supernova Project-II: A New Method to Photometrically Identify Sub-types of Extreme Type Ia Supernovae. We present a new method to photometrically delineate between various sub-types of Type Ia supernovae (SNe Ia). Using the color-stretch parameters, sBV or sgr, and the time of I-band primary maximum relative to the B-band ( ${t}_{\max }^{I-B}$ ) or g-band ( ${t}_{\max }^{I-g}$ ) maximum it is demonstrated that 2003fg-like, 1991bg-like, and 2002cx-like SNe Ia can be identified readily. In the cases of these extreme SNe Ia, their primary I-band maximum occurs after the time of the B- or g-band maxima. We suggest that the timing of the I-band maximum can reveal the physical state of the SN Ia explosion as it traces: (I) the speed of the recombination front of iron group elements in the ejecta, (II) the temperature evolution and rate of adiabatic cooling in the ejecta and, (III) the presence of interaction with a stellar envelope. This photometric sub-typing can be used in conjunction with other SNe analysis, such as the Branch diagram, to examine the physics and diversity of SNe Ia. The results here can also be used to screen out non-Ia SNe from cosmological samples that do not have complete spectroscopic typing. Finally, as future surveys like that of the Vera C. Rubin Observatory (previously referred to as the Large Synoptic Survey Telescope) create large databases of light curves of many objects this photometric identification can be used to readily identify and study the rates and bulk properties of peculiar SNe Ia.

Keywords: Time domain astronomy, Type Ia supernovae, Supernovae