Sazuna/UAT_keywords huggingface dataset:
ALMA-IMF. IX. Catalog and Physical Properties of 315 SiO Outflow Candidates in 15 Massive Protoclusters. We present a catalog of 315 protostellar outflow candidates detected in SiO J = 5 - 4 in the ALMA-IMF Large Program, observed with ~2000 au spatial resolution, 0.339 km s-1 velocity resolution, and 2-12 mJy beam-1 (0.18-0.8 K) sensitivity. We find median outflow masses, momenta, and kinetic energies of ~0.3 M ☉, 4 M ☉ km s-1, and 1045 erg, respectively. Median outflow lifetimes are 6000 yr, yielding median mass, momentum, and energy rates of $\dot{M}$ = 10-4.4 M ☉ yr-1, $\dot{P}$ = 10-3.2 M ☉ km s-1 yr-1, and $\dot{E}$ = 1 L ☉. We analyze these outflow properties in the aggregate in each field. We find correlations between field-aggregated SiO outflow properties and total mass in cores (~3σ-5σ), and no correlations above 3σ with clump mass, clump luminosity, or clump luminosity-to-mass ratio. We perform a linear regression analysis and find that the correlation between field-aggregated outflow mass and total clump mass-which has been previously described in the literature-may actually be mediated by the relationship between outflow mass and total mass in cores. We also find that the most massive SiO outflow in each field is typically responsible for only 15%-30% of the total outflow mass (60% upper limit). Our data agree well with the established mechanical force-bolometric luminosity relationship in the literature, and our data extend this relationship up to L ≥ 106 L ☉ and $\dot{P}$ ≥ 1 M ☉ km s-1 yr-1. Our lack of correlation with clump L/M is inconsistent with models of protocluster formation in which all protostars start forming at the same time.

Keywords: Interstellar molecules, Molecular gas, Massive stars, Stellar jets, Star forming regions, Protoclusters, Astrochemistry, Young stellar objects, Stellar winds, Protostars, Radio interferometry, Catalogs
An HST Study of the Substellar Population of NGC 2024. We performed an HST/WFC3-IR imaging survey of the young stellar cluster NGC 2024 in three filters probing the 1.4 μm H2O absorption feature, characteristic of the population of low-mass and substellar-mass objects down to a few Jupiter masses. We detect 812 point sources, 550 of them in all three filters with signal-to-noise ratio greater than 5. Using a distance-independent two-color diagram, we determine extinction values as high as A  V  ≃ 40. We also find that the change of effective wavelengths in our filters results in higher A  V  values as the reddening increases. Reconstructing a dereddened color-magnitude diagram, we derive a luminosity histogram both for the full sample of candidate cluster members and for an extinction-limited subsample containing the 50% of sources with A  V  ≲ 15. Assuming a standard extinction law like Cardelli et al. with a nominal R  V  = 3.1, we produce a luminosity function in good agreement with the one resulting from a Salpeter-like initial mass function for a 1 Myr isochrone. There is some evidence of an excess of luminous stars in the most embedded region. We posit that the correlation may be due to those sources being younger, and therefore overluminous, than the more evolved and less extincted cluster's stars. We compare our classification scheme based on the depth of the 1.4 μm photometric feature with the results from the spectroscopic survey of Levine et al., and we report a few peculiar sources and morphological features typical of the rich phenomenology commonly encountered in young star-forming regions.

Keywords: Young massive clusters, Pre-main sequence stars, Star formation
Orbital Decay of Hot Jupiters due to Weakly Nonlinear Tidal Dissipation. We study tidal dissipation in hot Jupiter host stars due to the nonlinear damping of tidally driven g-modes, extending the calculations of Essick &amp; Weinberg to a wide variety of stellar host types. This process causes the planet's orbit to decay and has potentially important consequences for the evolution and fate of hot Jupiters. Previous studies either only accounted for linear dissipation processes or assumed that the resonantly excited primary mode becomes strongly nonlinear and breaks as it approaches the stellar center. However, the great majority of hot Jupiter systems are in the weakly nonlinear regime in which the primary mode does not break but instead excites a sea of secondary modes via three-mode interactions. We simulate these nonlinear interactions and calculate the net mode dissipation for stars that range in mass from 0.5M ⊙ ≤ M ⋆ ≤ 2.0M ⊙ and in age from the early main sequence to the subgiant phase. We find that the nonlinearly excited secondary modes can enhance the tidal dissipation by orders of magnitude compared to linear dissipation processes. For the stars with M ⋆ ≲ 1.0M ⊙ of nearly any age, we find that the orbital decay time is ≲100 Myr for orbital periods P orb ≲ 1 day. For M ⋆ ≳ 1.2M ⊙, the orbital decay time only becomes short on the subgiant branch, where it can be ≲10 Myr for P orb ≲ 2 days and result in significant transit time shifts. We discuss these results in the context of known hot Jupiter systems and examine the prospects for detecting their orbital decay with transit timing measurements.

Keywords: Internal waves, Exoplanet migration, Hydrodynamics, Hot Jupiters, Tides
Coronal Heating and Solar Wind Generation by Flux Cancellation Reconnection. In this paper, we propose that flux cancellation on small granular scales (≲1000 km) ubiquitously drives reconnection at a multitude of sites in the low solar atmosphere, contributing to chromospheric/coronal heating and the generation of the solar wind. We analyze the energy conversion in these small-scale flux cancellation events using both analytical models and three-dimensional, resistive magnetohydrodynamic (MHD) simulations. The analytical models-in combination with the latest estimates of flux cancellation rates-allow us to estimate the energy release rates due to cancellation events, which are found to be on the order 106-107 erg cm-2 s-1, sufficient to heat the chromosphere and corona of the quiet Sun and active regions, and to power the solar wind. The MHD simulations confirm the conversion of energy in reconnecting current sheets, in a geometry representing a small-scale bipole being advected toward an intergranular lane. A ribbon-like jet of heated plasma that is accelerated upward could also escape the Sun as the solar wind in an open-field configuration. We conclude that through two phases of atmospheric energy release-precancellation and cancellation-the cancellation of photospheric magnetic flux fragments and the associated magnetic reconnection may provide a substantial energy and mass flux contribution to coronal heating and solar wind generation.

Keywords: Solar magnetic reconnection, Solar wind, Solar coronal heating, Solar physics, Solar magnetic fields, Solar chromospheric heating
All-sky Kinematics and Chemistry of Monoceros Stellar Overdensity. We explore the kinematic and chemical properties of the Monoceros stellar overdensity by combining data from the Two Micron All Sky Survey, Wide-field Infrared Survey Explorer, APOGEE, and Gaia. Monoceros is a structure located toward the Galactic anticenter and close to the disk. We have identified that its stars have azimuthal velocity in the range of 200 &lt; v  ϕ  (km s-1) &lt; 250. Combining their kinematics and spatial distribution, we designed a new method to select stars from this overdensity. This method allows us to easily identify the structure in both hemispheres and estimate their distances. Our analysis was supported by comparison with simulated data from the entire sky generated by the Galaxia code. Furthermore, we characterized, for the first time, the Monoceros overdensity in several chemical abundance spaces. Our results confirm its similarity to stars found in the thin disk of the Galaxy and suggest an in situ formation. Furthermore, we demonstrate that the southern and northern regions of Monoceros exhibit indistinguishable chemical compositions.

Keywords: Galactic archaeology, Milky Way disk, Milky Way dynamics, Chemical abundances
Stellar Half-mass Radii of 0.5 z &lt; 2.3 Galaxies: Comparison with JWST/NIRCam Half-light Radii. We use CEERS JWST/NIRCam imaging to measure rest-frame near-IR light profiles of 435 M ⋆ &gt; 1010 M ⊙ galaxies in the redshift range of 0.5 &lt; z &lt; 2.3. We compare the resulting rest-frame 1.5-2 μm half-light radii (R NIR) with stellar half-mass radii ( ${R}_{{{M}}_{\star }}$ ) derived with multicolor light profiles from CANDELS Hubble Space Telescope imaging. In general agreement with previous work, we find that R NIR and ${R}_{{{M}}_{\star }}$ are up to 40% smaller than the rest-frame optical half-light radius R opt. The agreement between R NIR and ${R}_{{{M}}_{\star }}$ is excellent, with a negligible systematic offset (&lt;0.03 dex) up to z = 2 for quiescent galaxies and up to z = 1.5 for star-forming galaxies. We also deproject the profiles to estimate ${R}_{{{M}}_{\star },3{\rm{D}}}$ , the radius of a sphere containing 50% of the stellar mass. We present the R-M ⋆ distribution of galaxies at 0.5 &lt; z &lt; 1.5, comparing R opt, ${R}_{{{M}}_{\star }}$ , and ${R}_{{{M}}_{\star },3{\rm{D}}}$ . The slope is significantly flatter for ${R}_{{{M}}_{\star }}$ and ${R}_{{{M}}_{\star },3{\rm{D}}}$ compared to R opt, mostly due to downward shifts in size for massive star-forming galaxies, while ${R}_{{{M}}_{\star }}$ and ${R}_{{{M}}_{\star },3{\rm{D}}}$ do not show markedly different trends. Finally, we show rapid evolution of the size (R ∝ (1 + z)-1.7±0.1) of massive (M ⋆ &gt; 1011 M ⊙) quiescent galaxies between z = 0.5 and z = 2.3, again comparing R opt, ${R}_{{{M}}_{\star }}$ , and ${R}_{{{M}}_{\star },3{\rm{D}}}$ . We conclude that the main tenets of the evolution of the size narrative established over the past 20 yr, based on rest-frame optical light profile analysis, still hold in the era of JWST/NIRCam observations in the rest-frame near-IR.

Keywords: Galaxy evolution
When and How Ram Pressure Stripping in Low-mass Satellite Galaxies Enhances Star Formation. We investigate how a satellite's star formation rate (SFR) and surviving gas respond to ram pressure stripping (RPS) in various environments. Using a suite of high-resolution wind tunnel simulations with radiative cooling, star formation, and supernovae feedback, we model the first infall orbit of a low-mass disk galaxy (M * = 109.7 M ⊙) in different host halos, ranging from Milky Way-like to cluster hosts. When the ram pressure is moderate, we find that the stripping satellite shows an enhanced SFR relative to the isolated control case, despite gas loss due to stripping. The SFR enhancement is caused, not directly by compression, but by ram-pressure-driven mass flows, which can increase the dense gas fraction in the central disk regions. The spatially resolved star formation main sequence and Kennicutt-Schmidt relations in our simulations are consistent with recent findings of the VERTICO and GASP surveys. Our results predict the environmental signals of RPS in future multiwavelength, high-angular resolution observations: the star formation and gas surface densities will be centralized, and symmetrically enhanced within the stripping radius.

Keywords: Hydrodynamical simulations, Galaxy interactions, Star formation, Interstellar medium
A Comprehensive Investigation of Metals in the Circumgalactic Medium of Nearby Dwarf Galaxies. Dwarf galaxies are found to have lost most of their metals via feedback processes; however, there still lacks consistent assessment on the retention rate of metals in their circumgalactic medium (CGM). Here we investigate the metal content in the CGM of 45 isolated dwarf galaxies with M * = 106.5-9.5 M ⊙ (M 200m = 1010.0-11.5 M ⊙) using the Hubble Space Telescope/Cosmic Origins Spectrograph. While H I (Lyα) is ubiquitously detected (89%) within the CGM, we find low detection rates (≈5%-22%) in C II, C IV, Si II, Si III, and Si IV, largely consistent with literature values. Assuming these ions form in the cool (T ≈ 104 K) CGM with photoionization equilibrium, the observed H I and metal column density profiles can be best explained by an empirical model with low gas density and high volume filling factor. For a typical galaxy with M 200m = 1010.9 M ⊙ (median of the sample), our model predicts a cool gas mass of M CGM,cool ~ 108.4 M ⊙, corresponding to ~2% of the galaxy's baryonic budget. Assuming a metallicity of 0.3 Z ⊙, we estimate that the dwarf galaxy's cool CGM likely harbors ~10% of the metals ever produced, with the rest either in more ionized states in the CGM or transported to the intergalactic medium. We further examine the EAGLE simulation and show that H I and low ions may arise from a dense cool medium, while C IV arises from a diffuse warmer medium. Our work provides the community with a uniform data set on dwarf galaxies' CGM that combines our recent observations, additional archival data and literature compilation, which can be used to test various theoretical models of dwarf galaxies.

Keywords: Dwarf galaxies, Metal line absorbers, Circumgalactic medium
Pure Spectroscopic Constraints on UV Luminosity Functions and Cosmic Star Formation History from 25 Galaxies at z <SUB>spec</SUB> = 8.61-13.20 Confirmed with JWST/NIRSpec. We present pure spectroscopic constraints on the UV luminosity functions and cosmic star formation rate (SFR) densities from 25 galaxies at z spec = 8.61-13.20. By reducing the JWST/NIRSpec spectra taken in multiple programs of Early Release Observation, Early Release Science, General Observer, and Director's Discretionary Time observations with our analysis technique, we independently confirm 16 galaxies at z spec = 8.61-11.40, including new redshift determinations, and a bright interloper at z spec = 4.91 that was claimed as a photometric candidate at z ~ 16. In conjunction with nine galaxies at redshifts up to z spec = 13.20 in the literature, we make a sample of 25 spectroscopically confirmed galaxies in total and carefully derive the best estimates and lower limits of the UV luminosity functions. These UV luminosity function constraints are consistent with the previous photometric estimates within the uncertainties and indicate mild redshift evolution toward z ~ 12, showing tensions with some theoretical models of rapid evolution. With these spectroscopic constraints, we obtain firm lower limits of the cosmic SFR densities and spectroscopically confirm a high SFR density at z ~ 12 beyond the constant star formation efficiency models, which supports earlier claims from the photometric studies. While there are no spectroscopically confirmed galaxies with very large stellar masses violating the ΛCDM model due to the removal of the bright interloper, we confirm star-forming galaxies at z spec = 11-13 with stellar masses much higher than model predictions. Our results indicate possibilities of high star formation efficiency (&gt;5%), a hidden active galactic nucleus, a top-heavy initial mass function (possibly with Population III), and large scatter/variance. Having these successful and unsuccessful spectroscopy results, we suggest observational strategies for efficiently removing low-redshift interlopers for future JWST programs.

Keywords: Galaxy formation, High-redshift galaxies, Galaxy evolution
Insight-HXMT Views Her X-1: Probing the Dependence of the Cyclotron Line Energy on Flux and Time. Recent observations of Her X-1 with NuSTAR (as well as with INTEGRAL, Swift, and Astrosat) have provided evidence that the nearly 20 yr-long decay of the cyclotron line energy since ~1994 has ended and that a stable value has replaced the decay. Using the observations of the Hard X-ray Modulation Telescope (Insight-HXMT) performed between 2017 July and 2020 February, we analyze the spectra of Her X-1 in its main-on state, focusing on tracing the evolution of cyclotron line energy. While our analysis of eight main-on observations with Insight-HXMT (two in coordination with NuSTAR) shows significant differences with the results of NuSTAR, two earlier findings are confirmed: the positive correlation between the cyclotron line energy and the X-ray flux (source luminosity) and the constancy of the flux-normalized cyclotron line energy during 2017-2020-albeit with significant uncertainty about the absolute value.

Keywords: Accretion, X-ray binary stars
Discovery of Two Different Full Disk Evolutionary Patterns of M-type T Tauri Stars with LAMOST DR8. The full disk, full of gas and dust, determines the upper limit of planet masses, and its lifetime is critical for planet formation, especially for giant planets. In this work, we studied the evolutionary timescales of the full disks of T Tauri stars (TTSs) and their relations to accretion. Combined with Gaia EDR3, Two Micron All Sky Survey, and Wide-field Infrared Survey Explorer data, 1077 disk-bearing TTS candidates were found in LAMOST DR8, and stellar parameters were obtained. Among them, 783 are newly classified by spectra as classical T Tauri stars (CTTSs; 169) or weak-lined T Tauri stars (WTTSs). Based on EW and FWHM of Hα, 157 TTSs in accretion were identified, with ~82% also having full disks. For TTSs with M &lt; 0.35M ☉, about 80% seem to already lose their full disks at ~0.1 Myr, which may explain their lower mass, while the remaining 20% with full disks evolve at similar rates of non-full disks within 5 Myr, allowing enough time and material to form giant planets. The fraction of accreting TTSs to disk-bearing TTSs is stable at ~10% and can last ~5-10 Myr, suggesting that full disks and accretion evolve with similar rates as non-full disks. For TTSs with M &gt; 0.35 M ☉, almost all full disks can survive more than 0.1 Myr, most for 1 Myr and some even for 20 Myr. For TTSs with M &gt; 0.35 M ☉, almost all full disks can survive more than 0.1 Myr, most for 1 Myr, and some even for 20 Myr, which implies planets are more likely to be formed in their disks than those of M &lt; 0.35 M ☉, and thus M dwarfs with M &gt; 0.35 M ☉ can have more planets. The fraction of full-disk TTSs to disk-bearing TTSs decreases with age following the relation f ∝ t -0.35, and similar relations existed in the fraction of accreting TTSs and the fraction of full-disk CTTSs, suggesting faster full disks and accretion evolution than non-full disks. For full-disk stars, the ratio of accretion of lower-mass stars is systematically lower than that of higher-mass stars, confirming the dependence of accretion on stellar mass, which may be reflective of an observational bias in the detection of accretion levels, with the lower-mass stars crossing below the detection threshold earlier than higher-mass stars.

Keywords: Accretion, T Tauri stars, Circumstellar disks
On the Formation and Interaction of Multiple Supermassive Stars in Cosmological Flows. Supermassive primordial stars with masses exceeding ~105 M ⊙ that form in atomically cooled halos are the leading candidates for the origin of high-redshift quasars at z &gt; 6. Recent numerical simulations, however, find that multiple accretion disks can form within a halo, each of which can potentially host a supermassive star. We investigate the formation and evolution of secondary supermassive stars in atomically cooled halos, including strong variations in their accretion histories driven by gravitational interactions between their disks and those surrounding the primary supermassive stars in each halo. We find that all secondary disks produce long-lived supermassive stars under sustained rapid accretion. We also find, however, that the majority of secondary supermassive stars do undergo at least one protracted quiescent accretion phase, during which time they thermally relax and may become powerful sources of ionizing feedback. In many halos, the two satellite disks collide, suggesting that the two stars can come into close proximity. This may induce additional mass exchange between them, leading to a great diversity of possible outcomes. These range from coevolution as main-sequence stars to main sequence-black hole pairs and black hole-black hole mergers. We discuss the likely outcome for these binary interactions based on the evolutionary state of both supermassive stars at the end of our simulations, as well as prospects for their future detection by current and next-generation facilities.

Keywords: Supermassive black holes, Population III stars, Primordial galaxies
First Chromospheric Activity and Doppler Imaging Study of PW And Using a New Doppler Imaging Code: SpotDIPy. Measuring the coverage of dark spots on cool stars is important to understanding how stellar magnetic activity scales with the rotation rate and convection zone depth. In this respect, it is crucial to infer surface magnetic patterns on G and K stars, to reveal solar-like stellar dynamos in action. Molecular bands serve as invaluable indicators of cool spots on the surfaces of stars, as they play a crucial role in enabling accurate assessments of the extent of spot coverage across the stellar surface. Therefore, more reliable surface images can be obtained considering the inversion of atomic lines with molecular bands. In this context, we simultaneously carry out Doppler imaging (DI) using atomic lines as well as titanium oxide band profiles of PW And (K2 V) and also investigate chromospheric activity indicators for the first time in the literature, using high-resolution spectra. The surface spot distribution obtained from the inversion process represents both atomic line and TiO-band profiles quite accurately. The chromospheric emission is also correlated with photospheric spot coverage, except during a possible flare event during the observations. We detect frequent flare activity, using TESS photometry. We also introduce a new open-source, Python-based DI code SpotDIPy that allows performing surface reconstructions of single stars using the maximum entropy method. We test the code by comparing surface reconstruction simulations with the extensively used DoTS code. We show that the surface brightness distribution maps reconstructed via both codes using the same simulated data are consistent with each other.

Keywords: Starspots, Doppler imaging, Stellar activity
Reconstructing the Hubble Parameter with Future Gravitational-wave Missions Using Machine Learning. We study the prospects of Gaussian processes (GPs), a machine-learning (ML) algorithm, as a tool to reconstruct the Hubble parameter H(z) with two upcoming gravitational-wave (GW) missions, namely, the evolved Laser Interferometer Space Antenna (eLISA) and the Einstein Telescope (ET). Assuming various background cosmological models, the Hubble parameter has been reconstructed in a nonparametric manner with the help of a GP using realistically generated catalogs for each mission. The effects of early-time and late-time priors on the reconstruction of H(z), and hence on the Hubble constant (H 0), have also been focused on separately. Our analysis reveals that a GP is quite robust in reconstructing the expansion history of the Universe within the observational window of the specific missions under consideration. We further confirm that both eLISA and ET would be able to provide constraints on H(z) and H 0, which would be competitive to those inferred from current data sets. In particular, we observe that an eLISA run of a ~10 yr duration with ~80 detected bright siren events would be able to constrain H 0 as precisely as a ~3 yr ET run assuming ~1000 bright siren event detections. Further improvement in precision is expected for longer eLISA mission durations such as a ~15 yr time frame having ~120 events. Lastly, we discuss the possible role of these future GW missions in addressing the Hubble tension, for each model, on a case-by-case basis.

Keywords: Gravitational wave detectors, Hubble diagram, Cosmological parameters, Observational cosmology, Interferometers, Hubble constant, Gravitational waves, Gaussian Processes regression