Sazuna/UAT_keywords huggingface dataset:
On the Hunt for the Origins of the Orphan-Chenab Stream: Detailed Element Abundances with APOGEE and Gaia. Stellar streams in the Galactic halo are useful probes of the assembly of galaxies like the Milky Way. Many tidal stellar streams that have been found in recent years are accompanied by a known progenitor globular cluster or dwarf galaxy. However, the Orphan-Chenab (OC) stream is one case where a relatively narrow stream of stars has been found without a known progenitor. In an effort to find the parent of the OC stream, we use astrometry from the early third data release of ESA's Gaia mission (Gaia EDR3) and radial velocity information from the Sloan Digital Sky Survey (SDSS)-IV Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey to find up to 13 stars that are likely members of the OC stream. We use the APOGEE survey to study the chemical nature (for up to 10 stars) of the OC stream in the α (O, Mg, Ca, Si, Ti, and S), odd-Z (Al, K, and V), Fe-peak (Fe, Ni, Mn, Co, and Cr), and neutron-capture (Ce) elemental groups. We find that the stars that make up the OC stream are not consistent with a monometallic population and have a median metallicity of -1.92 dex with a dispersion of 0.28 dex. Our results also indicate that the α elements are depleted compared to the known Milky Way populations and that its [Mg/Al] abundance ratio is not consistent with second-generation stars from globular clusters. The detailed chemical pattern of these stars, namely the [α/Fe]-[Fe/H] plane and the metallicity distribution, indicates that the OC stream progenitor is very likely to be a dwarf spheroidal galaxy with a mass of ~106 M ⊙.

Keywords: Stellar abundances, Stellar streams, Chemical abundances
Dissecting the Mid-infrared Heart of M83 with JWST. We present a first look at the MRS observations of the nucleus of the nearby galaxy M83, taken with MIRI on board JWST. The observations show a rich set of emission features from the ionized gas, warm molecular gas, and dust. To begin dissecting the complex processes in this part of the galaxy, we divide the observations into four different regions. We find that the strength of the emission features varies strongly from region to region, with the southeast region displaying the weakest features tracing the dust continuum and interstellar medium (ISM) properties. Comparison between the cold molecular gas traced by the 12CO (1-0) transition with the Atacama Large Millimeter/submillimeter Array and the H2 S(1) transition shows a similar spatial distribution. This is in contrast to the distribution of the much warmer H2 emission from the S(7) transition found to be concentrated around the optical nucleus. We use the rotational emission lines and model the H2 excitation to estimate a total molecular gas mass accounting for the warm H2 component of M(&gt;50 K) ${}_{{{\rm{H}}}_{2}}$ = 67.90 (±5.43) × 106 M ⊙. We compare this value to the total gas mass inferred by probing the cold H2 gas through the 12CO (1-0) emission, M(CO) ${}_{{{\rm{H}}}_{2}}$ = 17.15 × 106 M ⊙. We estimate that ~75% of the total molecular gas mass is contained in the warm H2 component. We also identify [O IV] 25.89 μm and [Fe II] 25.99 μm emission. We propose that the diffuse [Fe II] 25.99 μm emission might be tracing shocks created during the interactions between the hot wind produced by the starburst and the much cooler ISM above the galactic plane. More detailed studies are needed to confirm such a scenario.

Keywords: Starburst galaxies, Molecular gas, Interstellar medium
A Search for Kilonova Radio Flares in a Sample of Swift/BAT Short Gamma-Ray Bursts. The multimessenger detection of GW170817 showed that binary neutron star (BNS) mergers are progenitors of (at least some) short gamma-ray bursts (GRBs), and that short GRB jets (and their afterglows) can have structures (and observational properties) more complex than predicted by the standard top-hat jet scenario. Indeed, the emission from the structured jet launched in GW170817 peaked in the radio band (centimeter wavelengths) at ≈100 days since merger-a timescale much longer than the typical time span of radio follow-up observations of short GRBs. Moreover, radio searches for a potential late-time radio flare from the fast tail of the neutron-rich debris that powered the kilonova associated with GW170817 (AT 2017gfo) have extended to even longer timescales (years after the merger). In light of this, here we present the results of an observational campaign targeting a sample of seven, years-old GRBs in the Swift/BAT sample with no redshift measurements and no promptly identified X-ray counterpart. Our goal is to assess whether this sample of short GRBs could harbor nearby BNS mergers, searching for the late-time radio emission expected from their ejecta. We found one radio candidate counterpart for one of the GRBs in our sample, GRB 111126A, though an origin related to emission from star formation or from an active galactic nucleus in its host galaxy cannot be excluded without further observations.

Keywords: Radio continuum emission, Gamma-ray bursts, Non-thermal radiation sources, Gravitational waves
Spatially Resolved Properties of Galaxies at 5 &lt; z &lt; 9 in the SMACS 0723 JWST ERO Field. We present the first spatially resolved measurements of galaxy properties in the JWST ERO SMACS 0723 field. We perform a comprehensive analysis of five 5 &lt; z &lt; 9 galaxies with spectroscopic redshifts from NIRSpec observations. We perform spatially resolved spectral energy distribution fitting with BAGPIPES, using six NIRCam imaging bands spanning the wavelength range 0.8-5 μm. This approach allows us to study the internal structure and assembly of the first generations of galaxies. We find clear gradients both in the empirical color maps and in most of the estimated physical parameters. We find regions of considerably different specific star formation rates across each galaxy, which points to very bursty star formation happening on small scales, not galaxy-wide. The integrated light is dominated by these bursty regions, which exhibit strong line emission, with the equivalent width of [O III]+Hβ reaching up to ~3000-4000 Å rest frame. Studying these galaxies in an integrated approach yields extremely young inferred ages of the stellar population (&lt;10 Myr), which outshine older stellar populations that are only distinguishable in the spatially resolved maps. This leads to inferring ~0.5-1 dex lower stellar masses by using single-aperture photometry, when compared to resolved analyses. Such systematics would have strong implications in the shape and evolution of the stellar mass function at these early times, particularly while samples are limited to small numbers of the brightest candidates. Furthermore, the evolved stellar populations revealed in this study imply an extended process of early galaxy formation that could otherwise be hidden behind the light of the most recently formed stars.

Keywords: Extragalactic astronomy, Star forming regions, High-redshift galaxies
FAUST. VII. Detection of a Hot Corino in the Prototypical Warm Carbon-chain Chemistry Source IRAS 15398-3359. We have observed the low-mass protostellar source IRAS 15398-3359 at a resolution of 0.″2-0.″3, as part of the Atacama Large Millimeter/Submillimeter Array Large Program FAUST, to examine the presence of a hot corino in the vicinity of the protostar. We detect nine CH3OH lines including the high-excitation lines with upper-state energies up to 500 K. The CH3OH rotational temperature and the column density are derived to be ${119}_{-26}^{+20}$ K and ${3.2}_{-1.0}^{+2.5}\times {10}^{18}$ cm-2, respectively. The beam filling factor is derived to be ${0.018}_{-0.003}^{+0.005}$ , indicating that the emitting region of CH3OH is much smaller than the synthesized beam size and is not resolved. The emitting region of three high-excitation lines, 183,15-182,16, A (E u = 447 K), 193,16-192,17, A (E u = 491 K), and 203,17-202,18, A (E u = 537 K), is located within the 50 au area around the protostar and seems to have a slight extension toward the northwest. Toward the continuum peak, we also detect one emission line from CH2DOH and two features of multiple CH3OCHO lines. These results, in combination with previous reports, indicate that IRAS 15398-3359 is a source with hybrid properties showing both hot corino chemistry rich in complex organic molecules on small scales (~10 au) and warm carbon-chain chemistry rich in carbon-chain species on large scales (~100-1000 au). A possible implication of the small emitting region is further discussed in relation to the origin of the hot corino activity.

Keywords: Interstellar molecules, Radio astrometry, Astrochemistry, Star formation, Protostars
Nonlinear Damping and Field-aligned Flows of Propagating Shear Alfvén Waves with Braginskii Viscosity. Braginskii magnetohydrodynamics (MHD) provides a more accurate description of many plasma environments than classical MHD since it actively treats the stress tensor using a closure derived from physical principles. Stress tensor effects nonetheless remain relatively unexplored for solar MHD phenomena, especially in nonlinear regimes. This paper analytically examines nonlinear damping and longitudinal flows of propagating shear Alfvén waves. Most previous studies of MHD waves in Braginskii MHD have considered the strict linear limit of vanishing wave perturbations. We show that those former linear results only apply to Alfvén wave amplitudes in the corona that are so small as to be of little interest, typically a wave energy less than 10-11 times the energy of the background magnetic field. For observed wave amplitudes, the Braginskii viscous dissipation of coronal Alfvén waves is nonlinear and a factor around 109 stronger than predicted by the linear theory. Furthermore, the dominant damping occurs through the parallel viscosity coefficient η 0, rather than the perpendicular viscosity coefficient η 2 in the linearized solution. This paper develops the nonlinear theory, showing that the wave energy density decays with an envelope ${(1+z/{L}_{d})}^{-1}$ . The damping length L  d  exhibits an optimal damping solution, beyond which greater viscosity leads to lower dissipation as the viscous forces self-organize the longitudinal flow to suppress damping. Although the nonlinear damping greatly exceeds the linear damping, it remains negligible for many coronal applications.

Keywords: Space plasmas, Magnetohydrodynamics, Plasma physics, Solar wind, Solar coronal heating, Plasma astrophysics, Alfven waves, Solar corona, Solar coronal holes
Hotter than Expected: Hubble Space Telescope (HST)/WFC3 Phase-resolved Spectroscopy of a Rare Irradiated Brown Dwarf with Strong Internal Heat Flux. With infrared flux contrasts larger than typically seen in hot Jupiter, tidally locked white dwarf-brown dwarf binaries offer a superior opportunity to investigate atmospheric processes in irradiated atmospheres. NLTT5306 is such a system, with a M BD = 52 ± 3 M Jup brown dwarf, orbiting a T eff = 7756 ± 35 K white dwarf with an ultra-short period of ~102 minutes. We present Hubble Space Telescope/Wide Field Camera 3 spectroscopic phase curves of NLTT5306, consisting of 47 spectra from 1.1 to 1.7 μm with an average signal-to-noise ratio ~ 65 per wavelength. We extracted the phase-resolved spectra of the brown dwarf NLTT5306B, finding a small &lt;100 K day-night temperature difference (~5% of the average day-side temperature). Our best-fit model phase curves revealed a complex wavelength-dependence on amplitudes and relative phase offsets, suggesting longitudinal-vertical atmospheric structure. The night-side spectrum was well fit by a cloudy, nonirradiated atmospheric model while the day side was best matched by a cloudy, weakly irradiated model. Additionally, we created a simple radiative energy redistribution model of the atmosphere and found evidence for efficient day-to-night heat redistribution and a moderately high Bond albedo. We also discovered an internal heat flux much higher than expected given the published system age, leading to an age reassessment that resulted in NLTT5306B most likely being much younger. We find that NLTT5306B is the only known significantly irradiated brown dwarf where the global temperature structure is not dominated by external irradiation, but rather its own internal heat. Our study provides an essential insight into the drivers of global circulation and day-to-night heat transport as a function of irradiation, rotation rate, and internal heat.

Keywords: Hot Jupiters, White dwarf stars, Brown dwarfs, Exoplanet atmospheres
Electron Reacceleration via Ion Cyclotron Waves in the Intracluster Medium. In galaxy clusters, the intracluster medium (ICM) is expected to host a diffuse, long-lived, and invisible population of "fossil" cosmic-ray electrons (CRe) with 1-100 MeV energies. These CRe, if reaccelerated by 100× in energy, can contribute synchrotron luminosity to cluster radio halos, relics, and phoenices. Reacceleration may be aided by CRe scattering upon the ion-Larmor-scale waves that spawn when ICM is compressed, dilated, or sheared. We study CRe scattering and energy gain due to ion cyclotron (IC) waves generated by continuously driven compression in 1D fully kinetic particle-in-cell simulations. We find that pitch-angle scattering of CRe by IC waves induces energy gain via magnetic pumping. In an optimal range of IC-resonant momenta, CRe may gain up to ~10%-30% of their initial energy in one compression/dilation cycle with magnetic field amplification ~3-6×, assuming adiabatic decompression without further scattering and averaging over initial pitch angle.

Keywords: Non-thermal radiation sources, Intracluster medium, Plasma astrophysics, Cosmic rays
Isotope Exchange Reaction of OH<SUP>-</SUP> Anion with HD at Temperatures from 15 K up to 300 K: Ion Trap Study. This paper presents the results of an experimental study of the reaction of OH- anions with HD molecules leading to the formation of OD- anions. The study's main goal was to obtain the temperature dependence of the reaction rate coefficient and determine the reaction's enthalpy. This study was carried out at astrophysically relevant temperatures from 15 to 300 K. The reaction was studied using a temperature-variable cryogenic linear 22-pole radio-frequency ion trap. The rotational temperature of the OH- anions in the ion trap was characterized by near-threshold photodetachment spectroscopy. At 15 K, the measured reaction rate coefficient is 5 × 10-10 cm3 s-1. With increasing temperature, the reaction rate coefficient decreases monotonically to 5 × 10-11 cm3 s-1 at 300 K. Comparing with the previously determined rate coefficient of the reverse reaction of OD- anions with H2, we obtained the temperature dependence of the equilibrium constant. The enthalpy and entropy of the title reaction were determined in the studied temperature range as ΔH = (-23.9 ± 0.7 ± 2.6sys) meV and ΔS = (-8.5 ± 1.2 ± 1.4sys) J mol-1 K-1, respectively.

Keywords: Interstellar molecules, Isotopic abundances, Laboratory astrophysics, Reaction rates, Astrochemistry
A Glimpse of the Stellar Populations and Elemental Abundances of Gravitationally Lensed, Quiescent Galaxies at z ≳ 1 with Keck Deep Spectroscopy. Gravitational lenses can magnify distant galaxies, allowing us to discover and characterize the stellar populations of intrinsically faint, quiescent galaxies that are otherwise extremely difficult to directly observe at high redshift from ground-based telescopes. Here, we present the spectral analysis of two lensed, quiescent galaxies at z ≳ 1 discovered by the ASTRO 3D Galaxy Evolution with Lenses survey: AGEL1323 (M * ~ 1011.1 M ⊙, z = 1.016, μ ~ 14.6) and AGEL0014 (M * ~ 1011.5 M ⊙, z = 1.374, μ ~ 4.3). We measured the age, [Fe/H], and [Mg/Fe] of the two lensed galaxies using deep, rest-frame-optical spectra (S/N ≳40 Å-1) obtained on the Keck I telescope. The ages of AGEL1323 and AGEL0014 are ${5.6}_{-0.8}^{+0.8}$ Gyr and ${3.1}_{-0.3}^{+0.8}$ Gyr, respectively, indicating that most of the stars in the galaxies were formed less than 2 Gyr after the Big Bang. Compared to nearby quiescent galaxies of similar masses, the lensed galaxies have lower [Fe/H] and [Mg/H]. Surprisingly, the two galaxies have comparable [Mg/Fe] to similar-mass galaxies at lower redshifts, despite their old ages. Using a simple analytic chemical evolution model connecting the instantaneously recycled element Mg with the mass-loading factors of outflows averaged over the entire star formation history, we found that the lensed galaxies may have experienced enhanced outflows during their star formation compared to lower-redshift galaxies, which may explain why they quenched early.

Keywords: Metallicity, Abundance ratios, Galaxy properties, Stellar populations, Stellar abundances, Galaxy physics, Chemical abundances, Scaling relations, Galaxy ages, Gravitational lensing, Ground-based astronomy, High-redshift galaxies
Detection of Interstellar E-1-cyano-1,3-butadiene in GOTHAM Observations of TMC-1. We report the detection of the lowest-energy conformer of E-1-cyano-1,3-butadiene (E-1- ${{\rm{C}}}_{4}{{\rm{H}}}_{5}\mathrm{CN}$ ), a linear isomer of pyridine, using the fourth data reduction of the GBT Observations of TMC-1: Hunting for Aromatic Molecules (GOTHAM) deep spectral survey toward TMC-1 with the 100 m Green Bank Telescope. We perform velocity stacking and matched-filter analyses using Markov chain Monte Carlo simulations and find evidence for the presence of this molecule at the 5.1σ level. We derive a total column density of ${3.8}_{-0.9}^{+1.0}\times {10}^{10}$ cm-2, which is predominantly found toward two of the four velocity components we observe toward TMC-1. We use this molecule as a proxy for constraining the gas-phase abundance of the apolar hydrocarbon 1,3-butadiene. Based on the three-phase astrochemical modeling code NAUTILUS and an expanded chemical network, our model underestimates the abundance of cyano-1,3-butadiene by a factor of 19, with a peak column density of 2.34 × 1010 cm-2 for 1,3-butadiene. Compared to the modeling results obtained in previous GOTHAM analyses, the abundance of 1,3-butadiene is increased by about two orders of magnitude. Despite this increase, the modeled abundances of aromatic species do not appear to change and remain underestimated by one to four orders of magnitude. Meanwhile, the abundances of the five-membered ring molecules increase proportionally with 1,3-butadiene by two orders of magnitude. We discuss the implications for bottom-up formation routes to aromatic and polycyclic aromatic molecules.

Keywords: Interstellar molecules, Polycyclic aromatic hydrocarbons, Chemical abundances, Astrochemistry, Dark interstellar clouds
183 GHz Water Megamasers in Active Galactic Nuclei: A New Accretion Disk Tracer. We present the results of an Atacama Large Millimeter/submillimeter Array survey to identify 183 GHz H2O maser emission from active galactic nuclei (AGNs) already known to host 22 GHz megamaser systems. Out of 20 sources observed, we detect significant 183 GHz maser emission from 13; this survey thus increases the number of AGN known to host (sub)millimeter megamasers by a factor of 5. We find that the 183 GHz emission is systematically fainter than the 22 GHz emission from the same targets, with typical flux densities being roughly an order of magnitude lower at 183 GHz than at 22 GHz. However, the isotropic luminosities of the detected 183 GHz sources are comparable to their 22 GHz values. For two of our sources-ESO 269-G012 and the Circinus galaxy-we detect rich 183 GHz spectral structure containing multiple line complexes. The 183 GHz spectrum of ESO 269-G012 exhibits the triple-peaked structure characteristic of an edge-on AGN disk system. The Circinus galaxy contains the strongest 183 GHz emission detected in our sample, peaking at a flux density of nearly 5 Jy. The high signal-to-noise ratios achieved by these strong lines enable a coarse mapping of the 183 GHz maser system, in which the masers appear to be distributed similarly to those seen in VLBI maps of the 22 GHz system in the same galaxy and may be tracing the circumnuclear accretion disk at larger orbital radii than the 22 GHz masers. This newly identified population of AGN disk megamasers presents a motivation for developing VLBI capabilities at 183 GHz.

Keywords: Millimeter astronomy, Megamasers, Water masers, Active galactic nuclei, Astrophysical masers
Quijote-PNG: Quasi-maximum Likelihood Estimation of Primordial Non-Gaussianity in the Nonlinear Halo Density Field. We study primordial non-Gaussian signatures in the redshift-space halo field on nonlinear scales, using a quasi-maximum likelihood estimator based on optimally compressed power spectrum and modal bispectrum statistics. We train and validate the estimator on a suite of halo catalogs constructed from the QUIJOTE-PNG N-body simulations, which we release to accompany this paper. We verify its unbiasedness and near-optimality for the three main types of primordial non-Gaussianity (PNG): local, equilateral, and orthogonal. We compare the modal bispectrum expansion with a k-binning approach, showing that the former allows for faster convergence of numerical derivatives in the computation of the score function, thus leading to better final constraints. We find, in agreement with previous studies, that the local PNG signal in the halo field is dominated by the scale-dependent bias signature on large scales and saturates at k ~ 0.2 h Mpc-1, whereas the small-scale bispectrum is the main source of information for equilateral and orthogonal PNG. Combining the power spectrum and bispectrum on nonlinear scales plays an important role in breaking degeneracies between cosmological and PNG parameters; such degeneracies, however, remain strong for equilateral PNG. We forecast that PNG parameters can be constrained with ${\rm{\Delta }}{f}_{\mathrm{NL}}^{\mathrm{local}}=45$ , ${\rm{\Delta }}{f}_{\mathrm{NL}}^{\mathrm{equil}}=570$ , and ${\rm{\Delta }}{f}_{\mathrm{NL}}^{\mathrm{ortho}}=110$ on a cubic volume of $1{\left(\mathrm{Gpc}\,{h}^{-1}\right)}^{3}$ at z = 1, considering scales up to ${k}_{\max }=0.5\,h\,{\mathrm{Mpc}}^{-1}$ .

Keywords: Non-Gaussianity, Fisher's Information, Cosmological parameters from large-scale structure
The Role of Outflow Feedback on Accretion of Compact Objects in Accretion Disk of Active Galactic Nuclei. Compact objects (COs) can exist and evolve in an active galactic nuclei (AGN) disk, triggering a series of attractive CO-related multimessenger events around a supermassive black hole. To better understand the nature of an embedded CO and its surroundings and to investigate CO-related events more accurately, in this paper, we study the specific accretion process of a CO in an AGN disk and explore the role of outflow feedback. We show that the asymptotically isotropic outflow generated from the CO hyper-Eddington accretion would truncate the circum-CO disk and push out its surrounding gas, resulting in recurrent formation and refilling of an outflow cavity to intermittently stop the accretion. Applying this universal cyclic process to black holes (BHs) and neutron stars (NSs), we find that, even if it is above the Eddington rate, the mass rate accreted onto a BH is dramatically reduced compared with the initial gas captured rate and thus consumes little mass of the AGN disk; outflow feedback on an NS is generally similar, but possesses complexities on the existence of a stellar magnetic field and hard surface. We demonstrate that although outflow feedback itself may be unobservable, it remarkably alters the CO evolution via reducing its mass growth rate, and the AGN disk can survive from the otherwise drastic CO accretion overlooking outflow. In addition, we discuss the potential influence of an underdense cavity on CO-related events, which embodies the significant role of outflow feedback as well.

Keywords: Neutron stars, Accretion, Black holes, Active galactic nuclei, Compact objects