Sazuna/UAT_keywords huggingface dataset:
Elemental Abundances of the Super-Neptune WASP-107b's Host Star Using High-resolution, Near-infrared Spectroscopy. We present the first elemental abundance measurements of the K dwarf (K7V) exoplanet-host star WASP-107 using high-resolution (R ≃45,000), near-infrared (H- and K-band) spectra taken from Gemini-S/IGRINS. We use the previously determined physical parameters of the star from the literature and infer the abundances of 15 elements—C, N, O, Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, and Ni, all with precision &lt; 0.1 dex—based on model fitting using MARCS model atmospheres and the Turbospectrum spectral synthesis code. Our results show near-solar abundances and a carbon-to-oxygen ratio (C/O) of 0.50 ± 0.10, which is consistent with the solar value of 0.54 ± 0.09. The orbiting planet, WASP-107b, is a super-Neptune with a mass in the Neptune regime (=1.8 M Nep) and a radius close to Jupiter's (=0.94 R Jup). This planet is also being targeted by four JWST Cycle 1 programs in transit and eclipse, which should provide highly precise measurements of atmospheric abundances. This will enable us to properly compare the planetary and stellar chemical abundances, which is essential in understanding the formation mechanisms, internal structure, and chemical composition of exoplanets. Our study is a proof-of-concept that will pave the way for such measurements to be made for all of JWST's cooler exoplanet-host stars.

Keywords: K dwarf stars
Witnessing a Transformation to Blue-cored Dwarf Early-type Galaxies in Filaments and the Cluster Outskirts: Gas-phase Abundances and Internal Kinematics Perspectives. The presence of transitional dwarf galaxies in filaments and cluster outskirts may be closely related to preprocessing in the filament; however, the underlying mechanism is not yet comprehensively understood. We present the spatially resolved chemical and kinematical properties of three blue-cored dwarf early-type galaxies (dE(bc)s) in the Virgo cluster and Virgo-related filaments (Crater and Virgo III) using the Sydney-AAO Multi-object Integral-field spectrograph galaxy Survey. We map the spatial distribution of Hα, oxygen abundance (O/H), nitrogen-to-oxygen abundance ratio (N/O), stellar population age, and gas-stellar internal kinematics. We find irregular shapes of enhanced star-forming regions from the centers to the outlying regions of blue cores in dE(bc)s. These regions are relatively metal poor compared with the surrounding regions, rendering the overall metallicity gradient of each galaxy positive. Furthermore, they exhibit higher N/O ratios at a given O/H relative to their surroundings, implying metal-poor gas infall by external processes. The equivalent width of the Hα emission line in metal-poor regions indicates young age of star formation, 6-8 Myr. The disturbed ionized gas velocity field, one of the most prominent features of galaxy mergers is also discovered in two dE(bc)s. We propose that a moderately dense filament environment is favorable for the formation of blue cores in dEs, in which dE(bc)s in filaments may have already been transformed before they fall into the Virgo cluster. This process may contribute to the composition of galaxy population at the outskirts of the cluster.

Keywords: Galaxy chemical evolution, Large-scale structure of the universe, Stellar kinematics, Dwarf elliptical galaxies, Star formation, Galaxy evolution, Extragalactic astronomy
Planetesimal Initial Mass Functions Following Diffusion-regulated Gravitational Collapse. The initial mass function (IMF) of planetesimals is of key importance for understanding the initial stages of planet formation, yet theoretical predictions so far have been insufficient in explaining the variety of IMFs found in simulations. Here, we connect diffusion-tidal-shear limited planetesimal formation within the framework of a Toomre-like instability in the particle midplane of a protoplanetary disk to an analytic prediction for the planetesimal IMF. The shape of the IMF is set by the stability parameter Q p, which in turn depends on the particle Stokes number, the Toomre Q value of the gas, the local dust concentration, and the local diffusivity. We compare our prediction to high-resolution numerical simulations of the streaming instability and planetesimal formation via gravitational collapse. We find that our IMF prediction agrees with numerical results and is consistent with both the paradigm that planetesimals are born big and the power-law description commonly found in simulations.

Keywords: Astrophysical fluid dynamics, Protoplanetary disks, Planetesimals
Surveying the Giant H II Regions of the Milky Way with SOFIA: V. DR7 and K3-50. We present our fifth set of results from our mid-infrared imaging survey of Milky Way Giant H II (GH II) regions with our detailed analysis of DR7 and K3-50. We obtained 20/25 and 37 μm imaging maps of both regions using the FORCAST instrument on the Stratospheric Observatory For Infrared Astronomy. We investigate the multiscale properties of DR7 and K3-50 using our data in conjunction with previous multiwavelength observations. Near- to far-infrared spectral energy distributions of individual compact infrared sources were constructed and fitted with massive young stellar object (MYSO) models. We find eight out of the ten (80%) compact sources in K3-50 and three out of the four (75%) sources in DR7 are likely to be MYSOs. We derived luminosity-to-mass ratios of the extended radio subregions of DR7 and K3-50 to estimate their relative ages. The large spread in evolutionary state for the subregions in K3-50 likely indicates that the star-forming complex has undergone multiple star-forming events separated more widely in time, whereas the smaller spread in DR7 likely indicates the star formation subregions are more co-eval. DR7 and K3-50 have Lyman continuum photon rates just above the formal threshold criterion for being categorized as a GH II region (1050 photons s-1) but with large enough errors that this classification is uncertain. By measuring other observational characteristics in the infrared, we find that K3-50 has properties more akin to previous bona fide GH II regions we have studied, whereas DR7 has values more like those of the non-GH II regions we have previously studied.

Keywords: Compact H II region, Massive stars, Star forming regions, Infrared astronomy, Star formation, Interstellar medium, Infrared sources, Protostars, H II regions
A Diverse Population of z   2 ULIRGs Revealed by JWST Imaging. Four ultraluminous infrared galaxies (ULIRGs) observed with JWST/NIRcam in the Cosmos Evolution Early Release Science program offer an unbiased preview of the z ~ 2 ULIRG population. The objects were originally selected at 24 μm and have strong polycyclic aromatic hydrocarbon emission features observed with Spitzer/Infrared Spectrometer. The four objects have similar stellar masses of ~1011 M ⊙ but otherwise are quite diverse. One is an isolated disk galaxy, but it has an active nucleus as shown by X-ray observations and by a bright point-source nucleus. Two others are merging pairs with mass ratios of 6-7:1. One has active nuclei in both components, while the other has only one active nucleus: the one in the less-massive neighbor, not the ULIRG. The fourth object is clumpy and irregular and is probably a merger, but there is no sign of an active nucleus. The intrinsic spectral energy distributions for the four active galactic nuclei in these systems are typical of type-2 QSOs. This study is consistent with the idea that even if internal processes can produce large luminosities at z ~ 2, galaxy merging may still be necessary for the most luminous objects. The diversity of these four initial examples suggests that large samples will be needed to understand the z ~ 2 ULIRG population.

Keywords: Active galactic nuclei, Spectral energy distribution, Infrared galaxies, Ultraluminous infrared galaxies, High-redshift galaxies
Hanle Effect with Angle-dependent Partial Frequency Redistribution in Three-dimensional Media. There has been a constant improvement in the observational measurement of linear polarization in chromospheric spectral lines in the last three decades. However, modeling polarized profiles of these lines still remains incomplete, due to the lack of inclusion of fundamental physics in modeling efforts. To model the observed solar spectrum and its linear polarization, we need a solution to the polarized radiative transfer equation. The polarization in strong resonance lines originates from the scattering mechanism known as the partial frequency redistribution (PFR) of an anisotropic radiation field. The understanding of the linear polarization in spatially resolved structures needs radiative transfer solutions in multidimensional geometries. In this paper, we explore the effects of angle-dependent PFR on scattering polarization profiles formed in three-dimensional (3D) media. We find that the 3D geometry combined with angle-dependent PFR produces more scattering polarization than an angle-averaged one.

Keywords: Solar atmosphere, Magnetic fields, Radiative transfer
Grain Alignment and Rotational Disruption by Radiative Torques in Exoplanet Atmospheres. Dust clouds are ubiquitous in the atmospheres of hot Jupiters and affect their observable properties. The alignment of dust grains in the clouds and resulting dust polarization provide a promising way to study the magnetic fields of exoplanets. Moreover, the grain size distribution plays an important role in the physical and chemical processes in the atmospheres, which are rather uncertain. In this paper, we first study the grain alignment of dust grains in the atmospheres of hot Jupiters by radiative torques (RATs). We find that silicate grains can be aligned by RATs with the magnetic fields (B - RAT) due to the strong magnetic fields of hot Jupiters, but carbonaceous grains of diamagnetic material tend to be aligned with the radiation direction (k - RAT). At a low altitude of r &lt; 2R p, where R p is the planet radius, only large grains can be aligned, but tiny grains of a ~ 0.01 μm can be aligned at a high altitude of r &gt; 3R p. We then study the rotational disruption of dust grains by the RAT disruption (RAT-D) mechanism. We find that large grains can be disrupted by RAT-D into smaller sizes. Grains of high tensile strength are disrupted at an altitude of r &gt; 3R p, but grains of low tensile strength can be disrupted at a lower altitude. We suggest that the disruption of large grains into smaller ones can facilitate dust clouds escaping to high altitudes due to lower gravity and may explain the presence of high-altitude clouds in hot Jupiters, as well as superpuff atmospheres.

Keywords: Exoplanet atmospheric composition , Interplanetary dust, Interplanetary magnetic fields, Exoplanet atmospheres
Effective Temperature Estimations from Line Depth Ratios in the H- and K-band Spectra of IGRINS. Determining accurate effective temperatures of stars buried in the dust-obscured Galactic regions is extremely difficult from photometry. Fortunately, high-resolution infrared spectroscopy is a powerful tool for determining the temperatures of stars with no dependence on interstellar extinction. It has long been known that the depth ratios of temperature-sensitive and relatively insensitive spectral lines are excellent temperature indices. In this work, we provide the first extensive line depth ratio (LDR) method application in the infrared region that encompasses both the H and K bands (1.48 μm - 2.48 μm). We applied the LDR method to high-resolution (R ≃ 45,000) H- and K-band spectra of 110 stars obtained with the Immersion Grating Infrared Spectrograph. Our sample contained stars with 3200 &lt; T eff (K) &lt; 5500, 0.20 ≤ log g &lt; 4.6, and -1.5 &lt; [M/H] &lt; 0.5. The application of this method in the K band yielded 21 new LDR-T eff relations. We also report five new LDR-T eff relations found in the H-band region, augmenting the relations already published by other groups. The temperatures found from our calibrations provide reliable temperatures within ~70 K accuracy compared to spectral T eff values from the literature.

Keywords: Stellar spectral lines, Stellar effective temperatures, Stellar properties, Infrared spectroscopy
The ISM in the z = 6.9 Interacting Galaxies of SPT0311-58. SPT0311-58, a system of two interacting galaxies in the Epoch of Reionization, exists in one of the rarest, most massive dark matter halos theoretically possible in that era. Studying the interstellar medium (ISM) in these galaxies can illuminate the process of galaxy formation in the early Universe. In this work, we explore the multiphase ISM in this system, using ALMA observations of the [C II] 158, [O I] 146, [N II] 122, and [O III] 88 fine-structure lines and dust continuum. We find wide variations in line ratios between the eastern and western galaxies, as well as across the western galaxy. Continuum colors indicate that SPT0311-58 E has a higher ionization parameter ( $\mathrm{log}U\approx -2.8$ ) than SPT0311-58 W ( $\mathrm{log}U\approx -3.1$ ). The ratio of [O III] 88-[N II] 122 and the ionization parameter constraints combine to demonstrate near-solar metallicity in these objects just 800 Myr after the Big Bang.

Keywords: High-redshift galaxies, Interstellar medium
Global Electric Fields at Mars Inferred from Multifluid Hall-MHD Simulations. In the Martian induced magnetosphere, the motion of planetary ions is significantly controlled by the ambient electric fields, which can be decomposed into three components: the motional, Hall, and ambipolar electric fields. Each of them is dominant in different regions and provides the ion acceleration with a particular effectiveness. Therefore, it is necessary to characterize the global distribution of these electric field components. In this study, a global multifluid Hall-MHD model is applied, which considers the motional, Hall, and ambipolar electric fields in ion transport and magnetic induction equations to self-consistently investigate the morphology of the electric fields in the Martian space environment. Numerical results suggest that the motional electric field is dominant in the upstream of the bow shock and in the magnetosheath along the Z MSE direction, leading to the formation of the ion plume escape channel. At the bow shock, the ambipolar electric field points outward, to decelerate and deflect the solar wind plasma flow. In the magnetosheath region, the ambipolar and motional electric fields with inward direction tend to reaccelerate the solar wind ions. However, along the magnetic pileup boundary, the Hall electric field pointing outward prevents the solar wind ions from penetrating the Martian induced magnetosphere, which also prevails in the Martian magnetotail region, to accelerate the ions' tailward escape. This is the first systematic investigation of the global distribution of electric fields, which is helpful to understand the processes of ion acceleration/deceleration and escape within the Mars-solar wind interaction.

Keywords: Mars, Solar-planetary interactions, Magnetohydrodynamics
Imaging Molecular Outflow in Massive Star-forming Regions with HNCO Lines. Protostellar outflows are considered a signpost of star formation. These outflows can cause shocks in the molecular gas and are typically traced by the line wings of certain molecules. HNCO (4-3) has been regarded as a shock tracer because of the high abundance in shocked regions. Here we present the first imaging results of HNCO (4-3) line wings toward nine sources in a sample of 23 massive star-forming regions using the Instituto de Radioastronomía Milimétrica 30 m Telescope. We adopt the velocity range of the full width of HC3N (10-9) and H13CO+ (1-0) emissions as the central emission values, beyond which the emission from HNCO (4-3) is considered to be from line wings. The spatial distributions of the red and/or blue lobes of HNCO (4-3) emission nicely associate with those lobes of HCO+ (1-0) in most of the sources. High-intensity ratios of HNCO (4-3) to HCO+ (1-0) are obtained in the line wings. The derived column density ratios of HNCO to HCO+ are consistent with those previously observed toward massive star-forming regions. These results provide direct evidence that HNCO could trace outflow in massive star-forming regions. This work also implies that the formation of some HNCO molecules is related to shock, either on the grain surface or within the shocked gas.

Keywords: Interstellar molecules, Star forming regions, Interstellar clouds, Star formation, Interstellar medium
Revisiting the Chandra Observation on the Region of PSR J1809-193: Indication of the Existence of an X-Ray Halo and Implication for the Origin of HESS J1809-193. HESS J1809-193 is an extended TeV γ-ray source and the origin of its γ-ray emission remains ambiguous. The pulsar wind nebula (PWN) of PSR J1J1809-193 lying inside the extended γ-ray emission is a possible candidate. Powered by the central pulsar, ultrarelativistic electrons in the PWN can produce radio to X-ray emission through synchrotron and γ-ray emission by inverse Compton (IC) scattering. To check whether this PWN is the counterpart of HESS J1809-193, we analyzed the Chandra X-ray radial intensity profile and spectral index profile of this PWN. We then adopted a one-zone isotropic diffusion model to fit the keV and TeV data. We found diffuse nonthermal X-ray emission extending beyond the PWN, which is likely an X-ray halo radiated by escaping electron/positron pairs from the PWN. A relatively strong magnetic field of ~20 μG is required to explain the spatial evolution of the X-ray spectrum (i.e., the significant softening of the spectrum with increasing distance from the pulsar), which, however, would suppress the IC radiation of pairs. Our result implies that a hadronic component may be needed to explain HESS J1809-193.

Keywords: X-ray astronomy, High energy astrophysics, Gamma-ray sources, Non-thermal radiation sources, Pulsar wind nebulae
Unraveling Joint Evolution of Bars, Star Formation, and Active Galactic Nuclei of Disk Galaxies. We aim to unravel the interplay between bars, star formation (SF), and active galactic nuclei (AGNs) in barred galaxies. To this end, we utilize the SDSS DR12 to select a sample of nearby (0.02 &lt; z &lt; 0.06) disk galaxies that are suitable for bar examination (M  r  &lt; -20.12 and inclination ≲53°). We identify 3662 barred galaxies and measure the length and axis ratio of each bar. We invent new bar parameters that mitigate the stellar and bulge mass biases and show, for the first time, that the evolution of non-AGN and AGN-hosting barred galaxies should be tracked using different bar parameters: the bar length for non-AGN galaxies and the bar axis ratio for AGN-hosting galaxies. Our analysis confirms that barred galaxies have a higher specific SF rate than unbarred control galaxies. Moreover, we find a positive correlation of bar length with both the SF enhancement and the centrally star-forming galaxy fraction, indicating the interconnectivity of bars and SF through the bar-driven gas inflow. We also find that, while the AGN fraction of barred galaxies is the same as that of the unbarred control sample, galaxies hosting more massive black holes (BHs) have rounder (i.e., higher axis ratio) bars, implying that the bar is not a cause of AGN activity; rather, AGNs appear to regulate bars. Our findings corroborate theoretical predictions that bars in non-AGN galaxies grow in length, and bars in AGN-hosting galaxies become rounder as BHs grow and eventually get destroyed.

Keywords: Galaxy bars, Galaxy structure, Star formation, Active galactic nuclei, Galaxy evolution
The Hateful Eight: Connecting Massive Substructures in Galaxy Clusters like A2744 to Their Dynamical Assembly State Using the Magneticum Simulations. Substructures are known to be good tracers for the dynamical states and recent accretion histories of the most massive collapsed structures in the universe, galaxy clusters. Observations find extremely massive substructures in some clusters, especially Abell 2744 (A2744), which are potentially in tension with the ΛCDM paradigm because they are not found in simulations directly. However, the methods to measure substructure masses strongly differ between observations and simulations. Using the fully hydrodynamical cosmological simulation suite MAGNETICUM PATHFINDER, we develop a method to measure substructure masses in projection from simulations, similarly to the observational approach. We identify a simulated A2744 counterpart that not only has eight substructures of similar mass fractions but also exhibits similar features in the hot gas component. This cluster formed only recently through a major merger together with at least six massive minor merger events since z = 1, where previously the most massive component had a mass of less than 1 × 1014 M ⊙. We show that the mass fraction of all substructures and of the eighth substructure separately are excellent tracers for the dynamical state and assembly history for all galaxy cluster mass ranges, with high fractions indicating merger events within the last 2 Gyr. Finally, we demonstrate that the differences between subhalo masses measured directly from simulations as bound and those measured in projection are due to methodology, with the latter generally 2-3 times larger than the former. We provide a predictor function to estimate projected substructure masses from SUBFIND masses for future comparison studies between simulations and observations.

Keywords: Galaxy clusters, Galaxy formation, Cold dark matter, Computational methods
Inferring the Progenitor Mass-Kinetic Energy Relation of Stripped-envelope Core-collapse Supernovae from Nebular Spectroscopy. The relation between the progenitor mass and the kinetic energy of the explosion is a key toward revealing the explosion mechanism of stripped-envelope core-collapse supernovae (SESNe). Here, we present a method to derive this relation using the nebular spectra of SESNe, based on the correlation between [O I]/[Ca II], which is an indicator of progenitor mass, and the width of [O I], which measures the expansion velocity of the oxygen-rich material. To explain the correlation, the kinetic energy (E K) is required to be positively correlated with the progenitor mass as represented by the CO core mass (M CO). We demonstrate that SNe IIb/Ib and SNe Ic/Ic-BL follow the same M CO-E K scaling relation, which suggests that helium-rich and helium-deficient SNe share the same explosion mechanism. The M CO-E K relation derived in this work is compared with the ones derived from early phase observations. The results are largely in good agreement. Combined with early phase observations, the method presented in this work provides a chance to scan through the ejecta from the outermost region to the dense inner core, which is important to reveal the global properties of the ejecta and constrain the explosion mechanism of core-collapse SNe.

Keywords: Type Ib supernovae, Type Ic supernovae, Supernova dynamics, Core-collapse supernovae