adsabs/SciX_UAT_keywords huggingface dataset:
The UNCOVER Survey: A First-look HST+JWST Catalog of Galaxy Redshifts and Stellar Population Properties Spanning 0.2 ≲ z ≲ 15

The recent UNCOVER survey with the James Webb Space Telescope (JWST) exploits the nearby cluster A2744 to create the deepest view of our Universe to date by leveraging strong gravitational lensing. In this work, we perform photometric fitting of more than 50,000 robustly detected sources out to z ~ 15. We show the redshift evolution of stellar ages, star formation rates, and rest-frame colors across the full range of 0.2 ≲ z ≲ 15. The galaxy properties are inferred using the Prospector Bayesian inference framework using informative Prospector-β priors on the masses and star formation histories to produce joint redshift and stellar populations posteriors. Additionally, lensing magnification is performed on the fly to ensure consistency with the scale-dependent priors. We show that this approach produces excellent photometric redshifts with σ NMAD ~ 0.03, of a similar quality to the established photometric redshift code EAzY. In line with the open-source scientific objective of this Treasury survey, we publicly release the stellar population catalog with this paper, derived from our photometric catalog adapting aperture sizes based on source profiles. This release (the catalog and all related documentation are accessible via the UNCOVER survey web page: https://jwst-uncover.github.io/DR2.html#SPSCatalogs with a copy deposited to Zenodo at doi:10.5281/zenodo.8401181) includes posterior moments, maximum likelihood spectra, star formation histories, and full posterior distributions, offering a rich data set to explore the processes governing galaxy formation and evolution over a parameter space now accessible by JWST.

Keywords: abell clusters; catalogs; galaxy evolution; james webb space telescope; hubble space telescope; spectral energy distribution
Material Properties of Saturn's Interior from Ab Initio Simulations

We investigate the material properties of a mixture of hydrogen, helium, and oxygen representative of Saturn's interior at pressure-temperature conditions of a recent Saturn model (see Mankovich & Fortney) with molecular dynamics simulations based on density functional theory. Their model considers the demixing of hydrogen and helium and predicts a He-rich layer above a diluted core. We calculate the thermodynamic and transport properties and discuss the impact on Saturn's evolution and interior structure. We find a significant impact of the He-rich layer on the specific heat capacity, speed of sound, viscosity, diffusion coefficients, thermal and electrical conductivity, Lorenz number, and magnetic and thermal diffusivities.

Keywords: saturn; planetary structure; planetary science; solar system gas giant planets; quantum-chemical calculations; chemical thermodynamics; plasma physics; metallicity; molecular physics; planetary interior; theoretical models
TOI-942b: A Prograde Neptune in a 60 Myr Old Multi-transiting System

Mapping the orbital obliquity distribution of young planets is one avenue toward understanding mechanisms that sculpt the architectures of planetary systems. TOI-942 is a young field star, with an age of ~60 Myr, hosting a planetary system consisting of two transiting Neptune-sized planets in 4.3 and 10.1 day period orbits. We observed the spectroscopic transits of the inner Neptune TOI-942b to determine its projected orbital obliquity angle. Through two partial transits, we find the planet to be in a prograde orbit, with a projected obliquity angle of $| \lambda | ={1}_{-33}^{+41}$ deg. In addition, incorporating the light curve and the stellar rotation period, we find the true 3D obliquity to be ${2}_{-23}^{+27}$ deg. We explored various sources of uncertainties specific to the spectroscopic transits of planets around young active stars, and showed that our reported obliquity uncertainty fully encompassed these effects. TOI-942b is one of the youngest planets to have its obliquity characterized, and one of even fewer residing in a multi-planet system. The prograde orbital geometry of TOI-942b is in line with systems of similar ages, none of which have yet been identified to be in strongly misaligned orbits. * This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

Keywords: planetary system formation; planetary science; exoplanet dynamics; exoplanet systems; exoplanets; mini neptunes
Radio Observations of Six Young Type Ia Supernovae

Type Ia supernovae (SNe Ia) are important cosmological tools, probes of binary star evolution, and contributors to cosmic metal enrichment; yet, a definitive understanding of the binary star systems that produce them remains elusive. Of particular interest is the identity of the mass-donor companion to the exploding carbon-oxygen white dwarf (CO WD). In this work, we present early-time (first observation within 10 days post-explosion) radio observations of six nearby (within 40 Mpc) SNe Ia taken by the Jansky Very Large Array, which are used to constrain the presence of synchrotron emission from the interaction between ejecta and circumstellar material (CSM). The two motivations for these early-time observations are: (1) to constrain the presence of low-density winds and (2) to provide an additional avenue of investigation for those SNe Ia observed to have early-time optical/UV excesses that may be due to CSM interaction. We detect no radio emission from any of our targets. Toward our first aim, these non-detections further increase the sample of SNe Ia that rule out winds from symbiotic binaries and strongly accreting white dwarfs. and discuss the dependence on underlying model assumptions and how our observations represent a large increase in the sample of SNe Ia with low-density wind constraints. For the second aim, we present a radiation hydrodynamics simulation to explore radio emission from an SN Ia interacting with a compact shell of CSM, and find that relativistic electrons cannot survive to produce radio emission despite the rapid expansion of the shocked shell after shock breakout. The effects of model assumptions are discussed for both the wind and compact shell conclusions.

Keywords: supernovae; circumstellar gas; shocks; radiative transfer simulations
Hydrodynamic Simulations of Oxygen–Neon Classical Novae as Galactic 7Li Producers and Potential Accretion-induced Collapse Progenitors

We report on studies of classical nova (CN) explosions where we follow the evolution of thermonuclear runaways (TNRs) on oxygen–neon (ONe) white dwarfs (WDs). Using NOVA, a 1D hydrodynamic computer code, we accrete solar matter until the TNR is ongoing and then switch to a mixed composition. This approach is guided by the results of multidimensional studies of TNRs in WDs, which find that sufficient mixing with WD core material occurs after the TNR is well underway, and levels of enrichment of the CNONeMg elements are reached that agree with observations of CN ejecta abundances. Because the amount of accreted material is inversely proportional to the oxygen abundance, by first accreting solar matter, the amount of accreted material is larger than in those simulations with an initially enriched composition. We vary the mass of the WD (from 0.6 M ⊙ to 1.35 M ⊙) and the composition of the mixed materials. Our results show large enrichments of 7Be in the ejected gases, implying that ONe CNe and CO CNe may be responsible for a significant fraction (∼100 M ⊙) of the Galactic 7Li (∼1000 M ⊙). The production of 22Na and 26Al in CN explosions and the γ-ray emission predicted by our simulations are discussed. The WDs in all our simulations eject less material than they accrete and we predict that the WD is growing in mass as a consequence of the CN outburst. ONe CNe, therefore, may be an important channel for accretion-induced collapse events. *We dedicate this paper to the memory of R. Mark Wagner. Friend, collaborator, exemplary observational astronomer, and contributor to studies of classical novae and transient objects for more than 40 years. He will be missed.

Keywords: cataclysmic variable stars; novae; recurrent novae; symbiotic novae; galaxy abundances; galaxy chemical evolution; galactic abundances; isotopic abundances; overabundances
Tearing Instability and Periodic Density Perturbations in the Slow Solar Wind

In contrast with the fast solar wind, which originates in coronal holes, the source of the slow solar wind is still debated. Often intermittent and enriched with low first ionization potential elements—akin to what is observed in closed coronal loops—the slow wind could form in bursty events nearby helmet streamers. Slow winds also exhibit density perturbations that have been shown to be periodic and could be associated with flux ropes ejected from the tip of helmet streamers, as shown recently by the WISPR white-light imager on board Parker Solar Probe (PSP). In this work, we propose that the main mechanism controlling the release of flux ropes is a flow-modified tearing mode at the heliospheric current sheet (HCS). We use magnetohydrodynamic simulations of the solar wind and corona to reproduce realistic configurations and outflows surrounding the HCS. We find that this process is able to explain long (∼10-20 hr) and short (∼1-2 hr) timescales of density structures observed in the slow solar wind. This study also sheds new light on the structure, topology, and composition of the slow solar wind, and could be, in the near future, compared with white light and in situ PSP observations.

Keywords: slow solar wind; solar magnetic reconnection; magnetohydrodynamics; plasma astrophysics; solar wind
Back to Business: SLX 1746-331 after 13 Years of Silence

The black hole candidate system SLX 1746-331 was back to business in 2023, after a long silence of roughly 13 years. An outburst was observed thoroughly by Insight-HXMT and NICER. The outburst is characterized by spectral dominance of the soft state, where the joint Insight-HXMT and NICER spectral analysis shows the temperature dependence of the disk flux follows ${T}_{\mathrm{in}}^{3.98}$ , and thus suggests that the inner disk reaches its innermost stable circular orbit during almost the entire outburst. By assuming 0.3 L Edd for the peak flux and an inclination angle of zero degrees, the lower limit of the compact object hosted in this system is estimated as 3.28 ± 2.14 M ⊙. We also look into the relation between the disk temperature and disk flux for a sample of black hole systems, and by taking the disk temperature derived in the outburst of SLX 1746-331, such a relation results in a mass estimation of 5.2 ± 4.5 M ⊙. Finally, the spin of the compact object is constrained to be larger than 0.8 with the spectral model KERRBB.

Keywords: x-ray binary stars
Circumnuclear Multiphase Gas in the Circinus Galaxy. V. The Origin of the X-Ray Polarization in the Circinus Galaxy

The Imaging X-ray Polarimetry Explorer (IXPE) detected X-ray polarization in the nearest Seyfert 2 galaxy, the Circinus galaxy, for the first time. To reproduce the IXPE results, we computed the degree of polarization based on two types of radiative hydrodynamic simulations: a parsec-scale three-dimensional model and a sub-parsec-scale axisymmetric model with a higher spatial resolution. In a series of papers, we confirmed that these models naturally explain the multiwavelength observations of the Circinus galaxy from radio to X-rays. We used a Monte Carlo Simulation for Astrophysics and Cosmology code to compute the linear polarization of continuum emission. We found that the degree of polarization based on the parsec-scale radiation-driven fountain model was smaller than that observed with the IXPE. The degree of polarization based on the sub-parsec-scale model depends on the hydrogen number density of the disk (d), and the degree of polarization obtained from our simulation is consistent with that observed with the IXPE in the case of $\mathrm{log}d/{\mathrm{cm}}^{-3}\geqslant 13$ . We investigate where the photons are Compton scattered and imply that the origin of the X-ray polarization in the Circinus galaxy is the outflow inside 0.01 pc. In this case, the degree of polarization may change over a timescale of approximately 10 yr.

Keywords: active galactic nuclei; astrophysical black holes; high energy astrophysics; seyfert galaxies; supermassive black holes; x-ray active galactic nuclei
Lunar Exploration as a Probe of Ancient Venus

An ancient Venusian rock could constrain that planet's history and reveal the past existence of oceans. Such samples may persist on the Moon, which lacks an atmosphere and significant geological activity. We demonstrate that, if Venus' atmosphere was at any point thin and similar to Earth's, then asteroid impacts transferred potentially detectable amounts of Venusian surface material to the lunar regolith. Venus experiences an enhanced flux, relative to Earth, of asteroid collisions that eject lightly shocked (≲40 GPa) surface material. Initial launch conditions plus close encounters and resonances with Venus evolve ejecta trajectories into Earth-crossing orbits. Using analytic models for crater ejecta and N-body simulations, we find that more than 0.07% of the ejecta lands on the Moon. The lunar regolith will contain up to 0.2 ppm Venusian material if Venus lost its water in the last 3.5 Gyr. If water was lost more than 4 Gyr ago, 0.3 ppm of the deep megaregolith is of Venusian origin. About half of collisions between ejecta and the Moon occur at ≲6 km s-1, which hydrodynamical simulations have indicated is sufficient to avoid significant shock alteration. Therefore, recovery and isotopic analyses of Venusian surface samples would determine with high confidence both whether and when Venus harbored liquid oceans and/or a lower-mass atmosphere. Tests on brecciated clasts in existing lunar samples from Apollo missions may provide an immediate resolution. Alternatively, regolith characterization by upcoming lunar missions may provide answers to these fundamental questions surrounding Venus' evolution.

Keywords: venus; meteorites; impact phenomena
3D-DASH: The Widest Near-infrared Hubble Space Telescope Survey

The 3D-Drift And SHift (3D-DASH) program is a Hubble Space Telescope (HST) WFC3 F160W imaging and G141 grism survey of the equatorial COSMOS field. 3D-DASH extends the legacy of HST near-infrared imaging and spectroscopy to degree-scale swaths of the sky, enabling the identification and study of distant galaxies (z > 2) that are rare or in short-lived phases of galaxy evolution at rest-frame optical wavelengths. Furthermore, when combined with existing ACS/F814W imaging, the program facilitates spatially resolved studies of the stellar populations and dust content of intermediate redshift (0.5 < z < 2) galaxies. Here we present the reduced F160W imaging mosaic available to the community. Observed with the efficient DASH technique, the mosaic comprises 1256 individual WFC3 pointings, corresponding to an area of 1.35 deg2 (1.43 deg2 in 1912 when including archival data). The median 5σ point-source limit in H 160 is 24.74 ± 0.20 mag. We also provide a point-spread function (PSF) generator tool to determine the PSF at any location within the 3D-DASH footprint. 3D-DASH is the widest HST/WFC3 imaging survey in the F160W filter to date, increasing the existing extragalactic survey area in the near-infrared at HST resolution by an order of magnitude.

Keywords: high-redshift galaxies; galaxy evolution; near infrared astronomy; sky surveys
Hidden Companions to Intermediate-mass Stars. XVI. Unveiling a 41,300 au Companion to the Very Eccentric Binary Zeta Boötis

Zeta Boötis is a nearby 2.2 M ⊙ + 2.2 M ⊙ 125 yr period visual binary distinguished by its very high eccentricity e ≈ 0.98. Here we report that HIP 71759 is a very wide 1.65 M ⊙ companion to ζ Boo at a projected separation $\rho =13\buildrel{\,\prime}\over{.} 3\leftrightarrow {\rm{41,300}}\,\mathrm{au}$ , an association that has been missed in previous wide binary searches. We estimate a projected velocity difference Δv 2D = 0.86 ± 0.20 km s‑1 compared to the Newtonian 2D escape velocity v esc,2D = 0.5 km s‑1. We propose that the triple system is gravitationally bound and that it was once much more compact, with the outer companion exciting high amplitude Kozai–Lidov eccentricity oscillations in ζ Boo as it also migrated outwards by removing energy from the inner binary. The Galactic tidal field eventually shut off the triple interaction, freezing the e ≈ 0.98 eccentricity of ζ Boo.

Keywords: elliptical orbits; a stars; trinary stars
An Unusual Reservoir of Water Emission in the VV CrA A Protoplanetary Disk

We present an analysis of an unusual pattern of water vapor emission from the ~2 Myr old low-mass binary system VV CrA, as observed in IR spectra obtained with VLT-CRIRES, VLT-VISIR, and Spitzer-IRS. Each component of the binary shows emission from water vapor in both the L (~3 μm) and N (~12 μm) bands. The N-band and Spitzer spectra are similar to those previously observed from young stars with disks and are consistent with emission from an extended protoplanetary disk. Conversely, the CRIRES L-band data of VV CrA A show an unusual spectrum, which requires the presence of a water reservoir with high temperature (T ≳ 1500 K), column density (N H2O ~ 3 × 1020 cm-2), and turbulent broadening (v ~ 10 km s-1) but very small emitting area (A ≲ 0.005 au2). Similarity to previously observed water emission from V1331 Cyg and SVS 13 suggests that the presence of such a reservoir may be linked to evolutionary state, perhaps related to the presence of high accretion rates or winds. While the inner disk may harbor such a reservoir, simple Keplerian models do not match well with emitting line shapes, and alternative velocity fields must be considered. We also present a new idea, that the unusual emission could arise in a circumplanetary disk, embedded within the larger VV CrA A protoplanetary disk. Additional data are likely required to determine the true physical origin of this unusual spectral pattern.

Keywords: protoplanetary disks; astrochemistry; planet formation
Statistical Study of Ejections in Coronal Hole Regions As Possible Sources of Solar Wind Switchbacks and Small-scale Magnetic Flux Ropes

The omnipresence of transient fluctuations in the solar wind, such as switchbacks (SBs) and small-scale magnetic flux ropes (SMFRs), have been well observed by the in situ observation of Parker Solar Probe (PSP), yet their sources are not clear. Possible candidates fall into two categories: solar origin and in situ generation in the solar wind. Among the solar-origin scenarios, the small-scale activities (such as ejections and eruptions) in coronal hole (CH) regions, where solar wind originates, are suggested as candidates. Using full-disk extreme ultraviolet images from Atmospheric Imaging Assembly on board the Solar Dynamic Observatory, we identify small-scale ejections in CH regions during PSP Encounters 5, 7, and 8, and study their statistical properties. These ejections belong to two categories: standard jets and blowout jets. With 27,832 ejections identified in 24 days (about 2/3 of them are blowout jets), we updated the expected frequency for PSP to detect their counterparts in the heliospace. The ejections we identified are comparable to the frequency of PSP-detected SMFRs, but they are insufficient to serve as the only producer of SBs or SB patches. Certain smaller events missed by this study, such as jetlets, may fill the gap.

Keywords: solar coronal holes; solar coronal transients; jets
The R-Process Alliance: Chemodynamically Tagged Groups. II. An Extended Sample of Halo r-process-enhanced Stars

Orbital characteristics based on Gaia Early Data Release 3 astrometric parameters are analyzed for ~1700 r-process-enhanced (RPE; [Eu/Fe] > +0.3) metal-poor stars ([Fe/H] ≤ -0.8) compiled from the R-Process Alliance, the GALactic Archaeology with HERMES (GALAH) DR3 survey, and additional literature sources. We find dynamical clusters of these stars based on their orbital energies and cylindrical actions using the HDBSCAN unsupervised learning algorithm. We identify 36 chemodynamically tagged groups (CDTGs) containing between five and 22 members; 17 CDTGs have at least 10 member stars. Previously known Milky Way (MW) substructures such as Gaia-Sausage-Enceladus, the splashed disk, the metal-weak thick disk, the Helmi stream, LMS-1 (Wukong), and Thamnos are reidentified. Associations with MW globular clusters are determined for seven CDTGs; no recognized MW dwarf galaxy satellites were associated with any of our CDTGs. Previously identified dynamical groups are also associated with our CDTGs, adding structural determination information and possible new identifications. Carbon-enhanced metal-poor RPE (CEMP-r) stars are identified among the targets; we assign these to morphological groups in a Yoon-Beers A(C) c versus [Fe/H] diagram. Our results confirm previous dynamical analyses that showed RPE stars in CDTGs share common chemical histories, influenced by their birth environments.

Keywords: milky way dynamics; galaxy dynamics; galactic archaeology; milky way evolution; milky way formation; milky way stellar halo; r-process
Quasar Luminosity Function Modeled using a Tapered Power Law

The formation of Supermassive black holes (SMBHs) early in the universe challenges our understanding of black holes formation, since they appear to be well-established by several hundred millions of years after the big bang. Therefore, theories including direct-collapse black holes and times of super-Eddington accretion are utilized to explain the phenomenon. Quasars can be studied to help explain the growth of these SMBHs using the quasar luminosity function (QLF). The function used here to model the QLF is a four parametered function, the tapered power law. With further calculations, this data shows that periods of super-Eddington accretion are likely happening, and that the seed mass for these SMBHs ranges from about 102 to 105M⊙.

Keywords: quasars; supermassive black holes; luminosity function
The Diffusion Coefficient of the Splashback Mass Function as a Probe of Cosmology

We present an analytic model for the splashback mass function of dark matter halos, which is parameterized by a single coefficient and constructed in the framework of the generalized excursion set theory and the self-similar spherical infall model. The value of the single coefficient that quantifies the diffusive nature of the splashback boundary is determined at various redshifts by comparing the model with the numerical results from the Erebos N-body simulations for the Planck and the WMAP7 cosmologies. Showing that the analytic model with the best-fit coefficient provides excellent matches to the numerical results in the mass range of 5 ≤ M/(1012 h-1 M⊙) < 103, we employ the Bayesian and Akaike Information Criterion tests to confirm that our model is most preferred by the numerical results compared to previous models at redshifts of 0.3 ≤ z ≤ 3 for both of the cosmologies. We also found that the diffusion coefficient decreases almost linearly with redshift, converging to zero at a certain threshold redshift, zc, whose value significantly differs between the Planck and WMAP7 cosmologies. Our result implies that the splashback mass function of dark matter halos at z ≥ zc is well described by a parameter-free analytic formula and that zc may have the potential to independently constrain the initial conditions of the universe.

Keywords: large-scale structure of the universe; cosmological models