Sazuna/UAT_keywords huggingface dataset:
Digging into the Interior of Hot Cores with ALMA (DIHCA). I. Dissecting the High-mass Star-forming Core G335.579-0.292 MM1. We observed the high-mass star-forming region G335.579-0.292 with the Atacama Large Millimeter/submillimeter Array (ALMA) at 226 GHz with an angular resolution of 0"3 (∼1000 au resolution at the source distance). G335.579-0.292 hosts one of the most massive cores in the Galaxy (G335-MM1). The continuum emission shows that G335-MM1 fragments into at least five sources, while molecular line emission is detected in two of the continuum sources (ALMA1 and ALMA3). We found evidence of large- and small-scale infall in ALMA1 revealed by an inverse P-Cygni profile and the presence of a blueshifted spot at the center of the first moment map of the CH3CN emission. In addition, hot gas expansion in the innermost region is unveiled by a redshifted spot in the first moment map of HDCO and (CH3)2CO (both with Eu &gt; 1100 K). Our modeling reveals that this expansion motion originates close to the central source, likely due to reversal of the accretion flow induced by the expansion of the H II region, while infall and rotation motions originate in the outer regions. ALMA3 shows clear signs of rotation, with a rotation axis inclination with respect to the line of sight close to 90°, and a system mass (disk + star) in the range of 10-30 M⊙.

Keywords: Massive stars, Star forming regions, Star formation
RR Lyrae Variables in Messier 53: Near-infrared Period-Luminosity Relations and the Calibration Using Gaia Early Data Release 3. We present new near-infrared, JHKs, period-luminosity relations (PLRs) for RR Lyrae variables in the Messier 53 (M53 or NGC 5024) globular cluster. Multi-epoch JHKs observations, obtained with the WIRCam instrument on the 3.6 m Canada-France-Hawaii Telescope, are used for the first time to estimate precise mean magnitudes for 63 RR Lyrae stars in M53 including 29 fundamental-mode (RRab) and 34 first-overtone mode (RRc) variables. The JHKs-band PLRs for RR Lyrae stars are best constrained for RRab types with a minimal scatter of 22, 23, and 19 mmag, respectively. The combined sample of RR Lyrae is used to derive the Ks-band PLR, ${K}_{s}=-2.303(0.063)\mathrm{log}P+15.212(0.016)$ ,exhibiting a 1σ dispersion of only 0.027 mag. Theoretical period-luminosity-metallicity (PLZ) relations are used to predict parallaxes for 400 Galactic RR Lyrae, resulting in a median parallax zero-point offset of -7 ± 3 μas in Gaia Early Data Release 3 (EDR3), which increases to 22 ± 2 μas if the parallax corrections are applied. We also estimate a robust distance modulus, μM53 = 16.403 ± 0.024 (statistical) ± 0.033 (systematic) mag, to M53 based on theoretical calibrations. Homogeneous and precise mean magnitudes for RR Lyrae in M53 together with similar literature data for M3, M4, M5, and ω Cen are used to empirically calibrate a new RR Lyrae ${\mathrm{PLZ}}_{{K}_{s}}$ relation, ${K}_{s}=-0.848(0.007)\,-2.320(0.006)\mathrm{log}P+0.166(0.011)[\mathrm{Fe}/{\rm{H}}]$ ,anchored with Gaia EDR3 distances and theoretically predicted relations, and to simultaneously estimate precise RR Lyrae-based distances to these globular clusters.

Keywords: Globular star clusters, Stellar pulsations, Distance measure, Distance indicators, RR Lyrae variable stars
The Effect of Flow on the Resonance Absorption of Slow MHD Waves in Magnetic Flux Tubes. In this paper, we study kink and sausage oscillations in the presence of longitudinal background flow. We study the resonance absorption of kink and sausage modes in the slow continuum, under magnetic pore conditions, in the presence of flow. We determine the dispersion relation, and solve it numerically to find the frequencies and damping rates of the slow kink and sausage surface modes. We also obtain an analytical solution for the damping rate of the slow surface mode in the long wavelength limit. We show that in the presence of plasma flow, resonance absorption can result in strong damping for forward waves, and can be considered as an efficient mechanism to justify the extremely rapid damping of slow surface sausage waves observed in magnetic pores. Moreover, the plasma flow reduces the efficiency of resonance absorption to damp backward waves. With respect to pore conditions, resonance instability is avoided in our model.

Keywords: Solar atmosphere, Solar physics, Solar photosphere
On the Nature of Propagating Intensity Disturbances in Polar Plumes during the 2017 Total Solar Eclipse. The propagating intensity disturbances (PIDs) in plumes are still poorly understood, and their identity (magnetoacoustic waves or flows) remains an open question. We investigate PIDs in five plumes located in the northern polar coronal hole observed during the 2017 total solar eclipse. Three plumes are associated with coronal bright points, jets, and macrospicules at their base (active plumes), and the other two plumes are not (quiet plumes). The electron temperature at the base of the plumes is obtained from the filter ratio of images taken with the X-ray Telescope on board Hinode and the passband ratio around 400 nm from an eclipse instrument, the Diagnostic Coronagraph Experiment. The phase speed (vr), frequency (ω), and wavenumber (k) of the PIDs in the plumes are obtained by applying a Fourier transformation to the spacetime (r - t plane) plots in images taken with the Atmospheric Imaging Assembly (AIA) in three different wavelength channels (171, 193, and 211 Å). We found that the PIDs in the higher-temperature AIA channels, 193 and 211 Å, are faster than that of the cooler AIA 171 Å channel. This tendency is more significant for the active plumes than the quiet ones. The observed speed ratio (∼1.3) between the AIA 171 and 193 Å channels is similar to the theoretical value (1.25) of a slow magnetoacoustic wave. Our results support the idea that PIDs in plumes represent a superposition of slow magnetoacoustic waves and plasma outflows that consist of dense cool flows and hot coronal jets.

Keywords: Fast solar wind, Solar eclipses, Solar coronal heating, Solar coronal waves, X-ray bright point, Solar coronal holes, Solar coronal plumes
Tracing Young Star-forming Clumps in the Nearby Flocculent Spiral Galaxy NGC 7793 with UVIT Imaging. Star formation in galaxies is a hierarchical process with a wide range of scales, from smaller clusters to larger stellar complexes. Here, we present an ultra-violet imaging study of the nearby flocculent spiral galaxy NGC 7793, observed using the Ultra-Violet Imaging Telescope (UVIT). We find that the disk scale length estimated in Far-UV (2.64 ± 0.16 kpc) is larger than that in Near-UV (2.21 ± 0.21 Kpc) and optical (1.08 Kpc), which supports the inside-out growth scenario of the galaxy disk. The star-forming UV disk is also found to be contained within the extent of H I gas, with a column density greater than 1021 cm-2. With the spatial resolution of UVIT (1 pixel ∼ 6.8 pc), we identified 2046 young star-forming clumps in the galaxy with radii between ∼12 and 70 pc, which matches well with the size of giant molecular clouds (GMCs) detected in the galaxy. Around 61% of the regions identified in our study are younger than 20 Myr, which points to a recent enhancement in star formation across the galaxy. We also note that the youngest star-forming regions, with an age of &lt;10 Myr, distinctly trace the flocculent arms of the galaxy. The estimated mass of the clumps covers a range between 103 and 106M⊙. We notice a gradient in the mass distribution of identified clumps along the spiral arms. We also study the nuclear star cluster of the galaxy, finding that the stellar populations in the cluster outskirts are younger than the inner part.

Keywords: Ultraviolet astronomy, Star forming regions, Star formation, Spiral galaxies
[C II] and CO Emission along the Bar and Counter-arms of NGC 7479. We present new SOFIA [C II] and ALMA COJ=1→0 observations of the nearby asymmetric barred spiral galaxy NGC 7479. The data, which cover the whole bar of the galaxy and the counter-arms visible in the radio continuum, are analyzed in conjunction with a wealth of existing visible, infrared, radio, and X-ray data. As in most normal galaxies, the [C II] emission is generally consistent with emission from cooling gas excited by photoelectric heating in photodissociation regions. However, anomalously high [C II]/CO ratios are seen at the two ends of the counter-arms. Both ends show shell-like structures, possibly bubbles, in Hα emission. In addition, the southern end has [C II]-to-infrared emission ratios inconsistent with normal star formation. Because there is little H I emission at this location, the [C II] emission probably originates in warm shocked molecular gas heated by the interaction of the radio jet forming the counter-arms with the interstellar medium in the galaxy. At two other locations, the high [C II]/CO ratios provide evidence for the existence of patches of CO-dark molecular gas. The [C II] and CO observations also reveal resolved velocity components along the bar. In particular, the CO emission can be separated into two components associated with gas along the leading edge of the bar and gas trailing the bar. The trailing gas component that amounts to approximately 40% of the gas around the bar region may be related to a minor merger. * Based on SOFIA observations with FIFI-LS.

Keywords: Molecular gas, Barred spiral galaxies, Infrared galaxies
Relativistic Reflection in NGC 4151. We investigate the X-ray spectrum of the Seyfert galaxy NGC 4151 using the simultaneous Suzaku/NuSTAR observation and flux-resolved INTEGRAL spectra supplemented by Suzaku and XMM observations. Our best spectral solution indicates that the narrow Fe Kα line is produced in Compton-thin matter at a distance of several hundred gravitational radii. In such a model, we find a weak but significant relativistic reflection from a disk truncated at about 10 gravitational radii when the source is in bright X-ray states. We do not find evidence either for or against the presence of relativistic reflection in the dim X-ray state. We also rule out models with X-ray emission dominated by a source located very close to the black hole horizon, which was proposed in previous works implementing the lamppost geometry for this source. We point out that accurate computation of the thermal Comptonization spectrum and its distortion by strong gravity is crucial in applications of the lamppost geometry to the NuSTAR data.

Keywords: Accretion, Seyfert galaxies, X-ray active galactic nuclei, Relativistic disks
Dust Growth in Molecular Cloud Envelopes: A Numerical Approach. Variations in the grain size distribution are to be expected in the interstellar medium (ISM) owing to grain growth and destruction. In this work, we present a dust collision model to be implemented inside a magnetohydrodynamic (MHD) code that takes into account grain growth and shattering of charged dust grains of a given composition (silicate or graphite). We integrate this model in the MHD code Athena and build on a previous implementation of the dynamics of charged dust grains in the same code. To demonstrate the performance of this coagulation model, we study the variations in the grain size distribution of a single-sized population of dust with radius 0.05 μm inside several dust filaments formed during a 2D MHD simulation. We also consider a realistic dust distribution with sizes ranging from 50 Å to 0.25 μm and analyze the variations in both the size distribution for graphite and silicates and the far-ultraviolet extinction curve. From the obtained results, we conclude that the methodology here presented, based on the MHD evolution of the equation of motion for a charged particle, is optimal for studying the coagulation of charged dust grains in a diffuse regime such as a molecular cloud envelope. Observationally, these variations in the dust size distribution are translated into variations in the far-ultraviolet extinction curve, and they are mainly caused by small graphite dust grains.

Keywords: Interstellar dust, Ultraviolet extinction, Interstellar medium
Where Binary Neutron Stars Merge: Predictions from IllustrisTNG. The rate and location of binary neutron star (BNS) mergers are determined by a combination of the star formation history and the delay-time distribution (DTD) function. In this paper, we couple the star formation rate histories from the IllustrisTNG model to a series of varied assumptions for the BNS DTD to make predictions for the BNS merger host galaxy mass function. These predictions offer two outcomes: (i) in the near term they influence the BNS merger event follow-up strategy by scrutinizing where most BNS merger events are expected to occur, and (ii) in the long term they constrain the DTD for BNS merger events once the host galaxy mass function is observationally well determined. From our fiducial model analysis, we predict that 50% of BNS mergers will occur in host galaxies with stellar mass between 1010 and 1011 M⊙, 68% between 4 × 109 and 3 × 1011 M⊙, and 95% between 4 × 108 and 2 × 1012 M⊙. We find that the details of the DTD employed do not have a strong effect on the peak of the host mass function. However, varying the DTD provides enough spread that the true DTD can be determined from enough electromagnetic observations of BNS mergers. Knowing the true DTD can help us determine the prevalence of BNS systems formed through highly eccentric and short-separation fast-merging channels and can constrain the dominant source of r-process material.

Keywords: Neutron stars, Stellar mergers, Close binary stars, Gravitational waves, Compact objects, Magnetohydrodynamical simulations
Extreme High-velocity Outflows from High-redshift BOSS Quasars. It is common to assume that all narrow absorption lines (NALs) at extreme high-velocity shifts form in cosmologically intervening gas or galaxies unrelated to quasars. However, previous detailed studies of individual quasars have shown that some NALs at these large velocity shifts do form in high-speed quasar ejecta. We search for extreme high-velocity NAL outflows (with speeds ∼0.1c-0.2c) based on relationships with associated absorption lines (AALs) and broad absorption-line (BAL) outflows. We find that high-velocity NALs are strongly correlated with AALs, BALs, and radio loudness, indicating that a significant fraction of high-velocity systems are either ejected from the quasars or form in material swept up by the radio jets (and are not unrelated intervening gas). We also consider line-locked C IV doublets as another indicator of high-velocity NALs formed in outflows. The fact that line-locked NALs are highly ionized and correlated with BAL outflows and radio-loud quasars implies that physical line locking due to radiative forces is both common and real, which provides indirect evidence that a significant fraction of high-velocity NALs are intrinsic to quasars.

Keywords: Quasar absorption line spectroscopy, Quasars
Shock Cooling Emission from Extended Material Revisited. Following shock breakout, the emission from an astrophysical explosion is dominated by the radiation of shock-heated material as it expands and cools, known as shock cooling emission (SCE). The luminosity of SCE is proportional to the initial radius of the emitting material, which makes its measurement useful for investigating the progenitors of these explosions. Recent observations have shown some transient events have especially prominent SCE, indicating a large radius that is potentially due to low-mass extended material. Motivated by this, we present an updated analytic model for SCE that can be utilized to fit these observations and learn more about the origin of these events. This model is compared with numerical simulations to assess its validity and limitations. We also discuss SN 2016gkg and SN 2019dge, two transients with large early luminosity peaks that have previously been attributed to SCE of extended material. We show that their early power-law evolution and photometry are well matched by our model, strengthening support for this interpretation.

Keywords: Supernovae, Radiative transfer
Multidimensional Boltzmann Neutrino Transport Code in Full General Relativity for Core-collapse Simulations. We develop a neutrino transfer code for core-collapse simulations that directly solves the multidimensional Boltzmann equations in full general relativity. We employ the discrete ordinate method, which discretizes the 6D phase space. The code is an extension of our special relativistic code coupled to a Newtonian hydrodynamics code, which is currently employed for core-collapse supernova simulations. In order to demonstrate our code's capability to treat general relativistic effects, we conduct some tests. We first compute the free streaming of neutrinos in the Schwarzschild and Kerr spacetimes and compare the results with the geodesic curves; in the Schwarzschild case, we deploy not only a 1D grid in space under spherical symmetry but also a 2D spatial mesh under axisymmetry in order to assess the capability of the code to compute the spatial advection of neutrinos. Second, we calculate the neutrino transport in a fixed matter background, which is taken from a core-collapse supernova simulation with our general relativistic but spherically symmetric Boltzmann hydrodynamics code, to obtain a steady neutrino distribution; the results are compared with those given by the latter code.

Keywords: Neutron stars, Supernova neutrinos, Black holes, Gravitational collapse, Radiative transfer simulations
Hubble Space Telescope Observations of Two Faint Dwarf Satellites of Nearby LMC Analogs from MADCASH. We present a deep Hubble Space Telescope (HST) imaging study of two dwarf galaxies in the halos of Local Volume Large Magellanic Cloud (LMC) analogs. These dwarfs were discovered as part of our Subaru+Hyper Suprime-Cam MADCASH survey: MADCASH-1 is a satellite of NGC 2403 (D ∼ 3.2 Mpc), and MADCASH-2 is a previously unknown dwarf galaxy near NGC 4214 (D ∼ 3 Mpc). Our HST data reach &gt;3.5 mag below the tip of the red giant branch (TRGB) of each dwarf, allowing us to derive their structural parameters and assess their stellar populations. We measure TRGB distances ( ${D}_{\mathrm{MADCASH}-1}={3.41}_{-0.23}^{+0.24}$ Mpc, ${D}_{\mathrm{MADCASH}-2}={3.00}_{-0.15}^{+0.13}$ Mpc), and confirm the dwarfs' associations with their host galaxies. MADCASH-1 is a predominantly old, metal-poor stellar system (age ∼13.5 Gyr, [M/H] ∼ -2.0), similar to many Local Group dwarfs. Modelling of MADCASH-2's color-magnitude diagram suggests that it contains mostly ancient, metal-poor stars (age ∼13.5 Gyr, [M/H] ∼ -2.0), but that ∼10% of its stellar mass was formed 1.1-1.5 Gyr ago and ∼1% was formed 400-500 Myr ago. Given its recent star formation, we search MADCASH-2 for neutral hydrogen using the Green Bank Telescope, but find no emission and estimate an upper limit on the H I mass of &lt;4.8 × 104 M⊙. These are the faintest dwarf satellites known around host galaxies of LMC mass outside the Local Group (MV,MADCASH-1 = -7.81 ± 0.18, MV,MADCASH-2 = -9.15 ± 0.12), and one of them shows signs of recent environmental quenching by its host. Once the MADCASH survey for faint dwarf satellites is complete, our census will enable us to test predictions from cold dark matter models for hierarchical structure formation and discover the physical mechanisms by which low-mass hosts influence the evolution of their satellites. * Based in part on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

Keywords: Galaxy properties, Dwarf galaxies, Galaxy stellar content, HST photometry, H I line emission, Galaxy evolution, Dwarf spheroidal galaxies, Galaxy quenching
ALMA Observation of the Protoplanetary Disk around WW Cha: Faint Double-peaked Ring and Asymmetric Structure. We present Atacama Large Millimeter/submillimeter Array (ALMA) Band 6 observations of dust continuum emission of the disk around WW Cha. The dust continuum image shows a smooth disk structure with a faint (low-contrast) dust ring, extending from ∼40 au to ∼70 au, not accompanied by any gap. We constructed the simple model to fit the visibility of the observed data by using the Markov Chain Monte Carlo (MCMC) method and found that the bump (we call the ring without the gap the bump) has two peaks at 40 au and 70 au. The residual map between the model and observation indicates asymmetric structures at the center and the outer region of the disk. These asymmetric structures are also confirmed by model-independent analysis of the imaginary part of the visibility. The asymmetric structure at the outer region is consistent with a spiral observed by SPHERE. To constrain physical quantities of the disk (dust density and temperature), we carried out radiative transfer simulations. We found that the midplane temperature around the outer peak is close to the freezing temperature of CO on water ice (∼30 K). The temperature around the inner peak is about 50 K, which is close to the freezing temperature of H2S and also close to the sintering temperature of several species. We also discuss the size distribution of the dust grains using the spectral index map obtained within the Band 6 data.

Keywords: Observational astronomy, Protoplanetary disks, Circumstellar disks, Circumstellar dust, Planet formation
The 2175 Å Dust Feature in Star-forming Galaxies at 1.3 ≤ z ≤ 1.8: The Dependence on Stellar Mass and Specific Star Formation Rate. We present direct spectroscopic measurements of the broad 2175 Å absorption feature in 505 star-forming main-sequence galaxies at 1.3 ≤ z ≤ 1.8 using individual and stacked spectra from the zCOSMOS-deep survey. Significant 2175 Å excess absorption features of moderate strength are measured, especially in the composite spectra. The excess absorption is well described by a Drude profile. The bump amplitude expressed in units of k(λ) = A(λ)/E(B - V), relative to the featureless Calzetti et al. law, has a range Bk ≍ 0.2-0.8. The bump amplitude decreases with the specific star formation rate (sSFR), while it increases moderately with the stellar mass. However, a comparison with local "starburst" galaxies shows that the high-redshift main-sequence galaxies have stronger bump features, despite having a higher sSFR than the local sample. Plotting the bump strength against the ${\rm{\Delta }}\mathrm{logsSFR}\equiv \mathrm{log}\left(\mathrm{SFR}/{\mathrm{SFR}}_{\mathrm{MS}}\right)$ relative to the main sequence, however, brings the two samples into much better concordance. This may indicate that it is the recent star formation history of the galaxies that determines the bump strength through the destruction of small carbonaceous grains by supernovae and intense radiation fields coupled with the time delay of ∼1 Gyr in the appearance of carbon-rich asymptotic giant branch stars.

Keywords: Interstellar dust, Interstellar dust extinction, Galaxy evolution, Interstellar medium