adsabs/SciX_UAT_keywords huggingface dataset:
The TESS Grand Unified Hot Jupiter Survey. I. Ten TESS Planets

Hot Jupiters-short-period giant planets-were the first extrasolar planets to be discovered, but many questions about their origin remain. NASA's Transiting Exoplanet Survey Satellite (TESS), an all-sky search for transiting planets, presents an opportunity to address these questions by constructing a uniform sample of hot Jupiters for demographic study through new detections and unifying the work of previous ground-based transit surveys. As the first results of an effort to build this large sample of planets, we report here the discovery of 10 new hot Jupiters (TOI-2193A b, TOI-2207b, TOI-2236b, TOI-2421b, TOI-2567b, TOI-2570b, TOI-3331b, TOI-3540A b, TOI-3693b, TOI-4137b). All of the planets were identified as planet candidates based on periodic flux dips observed by TESS, and were subsequently confirmed using ground-based time-series photometry, high-angular-resolution imaging, and high-resolution spectroscopy coordinated with the TESS Follow-up Observing Program. The 10 newly discovered planets orbit relatively bright F and G stars (G < 12.5, T eff between 4800 and 6200 K). The planets' orbital periods range from 2 to 10 days, and their masses range from 0.2 to 2.2 Jupiter masses. TOI-2421b is notable for being a Saturn-mass planet and TOI-2567b for being a "sub-Saturn," with masses of 0.322 ± 0.073 and 0.195 ± 0.030 Jupiter masses, respectively. We also measured a detectably eccentric orbit (e = 0.17 ± 0.05) for TOI-2207b, a planet on an 8 day orbit, while placing an upper limit of e < 0.052 for TOI-3693b, which has a 9 day orbital period. The 10 planets described here represent an important step toward using TESS to create a large and statistically useful sample of hot Jupiters.

Keywords: exoplanets; hot jupiters; transits; exoplanet astronomy; exoplanet detection methods
Recalculated Orbits Of Binaries and New Linear Solutions

In this paper we present recalculated orbital elements for nine binaries: EGG 2Aa, Ab, COU 1085, COU 1897, COU 1006, A 578Aa, Ab, A 1400, A 606, BU 984, and BU 992. Seven binaries have orbital periods longer than 100 yr, and two binaries have shorter orbital periods, 38 and 76 yr. Also, we present linear solutions determined for three double stars: COU 966, J838, and A 1247. In addition to the orbital elements for nine binaries, we give absolute magnitudes, spectral types, estimates of the masses, dynamical parallaxes, and for all 12 pairs the (O - C) residuals in θ and ρ.

Keywords: visual binary stars; fundamental parameters of stars
Rotational Stalling Ends when Main-sequence Core Temperatures are at a Minimum

Low-mass stars spin-down over time due to angular momentum loss from magnetized stellar winds. This spin-down is interrupted by an epoch of stalling where stars halt their spin-down for 0.1-2 Gyr. Duration of the stalling epoch is mass-dependent, with higher mass stars spending less time stalled than the lowest mass stars. We demonstrate that the mass-dependent age at which stars resume spinning down correlates with the age where low-mass stars are predicted to achieve their minimum core temperature on the main sequence. This suggests that the stalling epoch is commensurate with a phase in low-mass main-sequence star evolution where stars develop a small convective core and their convective envelopes are growing in mass.

Keywords: low mass stars; m dwarf stars; stellar structures; stellar interiors; stellar rotation; stellar convection envelopes; stellar convective zones; stellar evolutionary models
Disks and Outflows in the Intermediate-mass Star-forming Region NGC 2071 IR

We present Atacama Large Millimeter Array band 6/7 (1.3 mm/0.87 mm) and Very Large Array Ka-band (9 mm) observations toward NGC 2071 IR, an intermediate-mass star-forming region. We characterize the continuum and associated molecular line emission toward the most luminous protostars, i.e., IRS1 and IRS3, on ~100 au (0.″2) scales. IRS1 is partly resolved in the millimeter and centimeter continuum, which shows a potential disk. IRS3 has a well-resolved disk appearance in the millimeter continuum and is further resolved into a close binary system separated by ~40 au at 9 mm. Both sources exhibit clear velocity gradients across their disk major axes in multiple spectral lines including C18O, H2CO, SO, SO2, and complex organic molecules like CH3OH, 13CH3OH, and CH3OCHO. We use an analytic method to fit the Keplerian rotation of the disks and give constraints on physical parameters with a Markov Chain Monte Carlo routine. The IRS3 binary system is estimated to have a total mass of 1.4-1.5 M ⊙. IRS1 has a central mass of 3-5 M ⊙ based on both kinematic modeling and its spectral energy distribution, assuming that it is dominated by a single protostar. For both IRS1 and IRS3, the inferred ejection directions from different tracers, including radio jet, water maser, molecular outflow, and H2 emission, are not always consistent, and for IRS1 these can be misaligned by ~50°. IRS3 is better explained by a single precessing jet. A similar mechanism may be present in IRS1 as well but an unresolved multiple system in IRS1 is also possible.

Keywords: protostars; protoplanetary disks; stellar jets; star formation
Single- and Double-electron Capture Cross Sections for O6+ Ion in Collisions with H2 Molecules

Single- and double-electron capture (SEC and DEC) processes occurring in O6+ and H2 collisions are investigated in a wide-energy domain ranging from 0.1 to 100 keV u-1. Total and partial cross sections are calculated using a three-center, two-active-electron, semiclassical nonperturbative approach. To date, our close-coupling description of the collision is the most elaborate one in terms of accounting for electron correlation, molecular structures, and active channels. Our results are, in general, in good agreement with the available experimental ones for both total and partial cross sections. The comparison between the present calculations and available experimental data suggests that about 70% of the autoionization double capture may contribute to the measured SEC cross sections through postcollisional autoionization, while the stabilization of 30% of doubly excited states via the autotransfer to Rydberg states mechanism contributes to the measured DEC ones. Furthermore, we extend the understanding of the electron-capture processes on this system to impact energies above 20 keV u-1 for which no data exists. Our work provides new data for these electronic processes, which will be helpful for modeling astrophysical X-ray emissions induced by charge exchange.

Keywords: atomic physics; collisional processes; atomic data; charge transfer; charge exchange recombination
An Algorithm to Mitigate Charge Migration Effects in Data from the Near Infrared Imager and Slitless Spectrograph on the James Webb Space Telescope

We present an algorithm that mitigates the effects of charge migration due to the "brighter-fatter effect" (BFE) that occurs for highly illuminated stars in the Teledyne HAWAII-2RG detectors used in the NIRCam, NIRISS, and NIRSpec science instruments aboard the James Webb Space Telescope (JWST). The impact of this effect is most significant for photometry and spectrophotometry of bright stars in data for which the point-spread function (PSF) is undersampled, which is the case for several observing modes of the NIRISS instrument. The main impact of BFE to NIRISS data is incorrect count rate determinations for pixels in the central regions of PSFs of bright stars due to jump detections that are caused by charge migration from peak pixels to surrounding pixels. The effect is especially significant for bright compact sources in resampled, distortion-free images produced by the drizzle algorithm: quantitatively, apparent flux losses of >50% can occur in such images due to BFE. We describe the algorithm of the "charge_migration" mitigation step that has been implemented in version 10.0 of the operational JWST calibration pipeline as of 2023 December 5. We illustrate the impact of this step in terms of the resulting improvements of the precision of imaging photometry of point sources. The algorithm renders the effects of BFE on photometry and surface brightness measurements to stay within 1%. *This work is based on observations made with the NASA/ESA/CSA James Webb Space Telescope. The data were obtained from the Mikulski Archive for Space Telescopes at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-03127 for JWST. These observations are associated with programs #1083, 1093, 1094, and 1096.

Keywords: astronomical instrumentation; infrared photometry; direct imaging; astronomy data analysis; infrared observatories
Hidden Companions Detected by Asteroseismology. II. A Long-period Noneclipsing Binary System Revealed by Kepler and TESS

The detection of long-period binary stars containing a δ Scuti variable is helpful to study the formation and evolution of binaries in the intermediate-mass region. The phase modulation and the frequency modulation caused by the light travel effect make it possible to find such systems that are hard to be detected by other methods. In this paper, we combined Kepler and TESS data to extend the observation span to more than 12 yr. Time-frequency analysis was applied on some δ Scuti variables observed by both Kepler and TESS. After careful phase modulation analysis, we succeeded in detecting a binary system with an orbital period as long as 3924 days. The 525 s light travel time along the line of sight indicates that the hidden companion of KIC 3440495 is a stellar object. To date, it is the longest-period binary confirmed by the phase modulation method. The method described in this article can be applied to more Kepler and TESS pulsating variables in the future.

Keywords: binary stars; stellar oscillations; fundamental parameters of stars; delta scuti variable stars; photometry
A Red Giants' Toy Story

In spite of the spectacular progress accomplished by stellar evolution theory, some simple questions remain unanswered. One of these questions is "Why do stars become red giants?". Here we present a relatively simple analytical answer to this question. We validate our analysis by constructing a quantitative toy model of a red giant and comparing its predictions to full stellar evolutionary models. We find that the envelope forces the value of ${\rm{\nabla }}=d\mathrm{ln}T/d\mathrm{ln}P$ at, and above, the burning shell into a very narrow range of possible values. Together with the fact that the stellar material at the burning shell both provides and transports most of the stellar luminosity, this leads to tight relations between the thermodynamic variables at the burning shell and the mass and radius of the core-T s (M c , R s ), P s (M c , R s ), and ρ s (M c , R s ). When complemented by typical mass-radius relations of the helium cores, this implies that for all stellar masses the evolution of the core dictates the values of T s , P s , and ρ s . We show that for all stellar masses evolution leads to an increase in the pressure and density contrasts between the shell and the core, forcing a huge expansion of the layers on top of the burning shell. Besides explaining why stars become red giants our analysis also offers a mathematical demonstration of the so-called shell homology relations, and provides simple quantitative answers to some properties of low-mass red giants.

Keywords: stellar structures; red giant stars; stellar interiors; giant branch
Ion Cloud Expansion after Hyper-velocity Dust Impacts Detected by the Magnetospheric Multiscale Mission Electric Probes in the Dipole Configuration

Dust impact detection by electric field instruments is a well-established technique. On the other hand, not all aspects of signal generation by dust impacts are completely understood. We present a study of events related to dust impacts on the spacecraft body detected by electric field probes operating simultaneously in the monopole (probe-to-spacecraft potential measurement) and dipole (probe-to-probe potential measurement) configurations by the Earth-orbiting Magnetospheric Multiscale mission spacecraft. This unique measurement allows us to investigate connections between monopole and dipole data. Our analysis shows that the signal detected by the electric field instrument in a dipole configuration is generated by an ion cloud expanding along the electric probes. In this case, expanding ions affect not only the potential of the spacecraft body but also one or more electric probes at the end of antenna booms. Electric probes located far from the spacecraft body can be influenced by an ion cloud only when the spacecraft is located in tenuous ambient plasma inside of the Earth's magnetosphere. Derived velocities of the expanding ions on the order of tens of kilometers per second are in the range of values measured experimentally in the laboratory.

Keywords: interstellar dust; very small grains; plasma clouds; interplanetary dust; meteoroid dust clouds
Asymmetries of Heavy Elements in the Young Supernova Remnant Cassiopeia A

Supernova remnants (SNRs) offer the means to study supernovae (SNe) long after the original explosion and can provide a unique insight into the mechanism that governs these energetic events. In this work, we examine the morphologies of X-ray emission from different elements found in the youngest known core-collapse SNR in the Milky Way, Cassiopeia A. The heaviest elements exhibit the highest levels of asymmetry, which we relate to the burning process that created the elements and their proximity to the center of explosion. Our findings support recent model predictions that the material closest to the source of explosion will reflect the asymmetries inherent to the SN mechanism. Additionally, we find that the heaviest elements are moving more directly opposed to the neutron star (NS) than the lighter elements. This result is consistent with NS kicks arising from ejecta asymmetries.

Keywords: supernova remnants; neutron stars; spectroscopy; x-ray telescopes; x-ray observatories; astronomy data modeling; core-collapse supernovae
Detection of GeV Emission from an Ultralong Gamma-Ray Burst with the Fermi Large Area Telescope

GRB 220627A, detected by Fermi Gamma-ray Burst Monitor (GBM), shows two episodes of gamma-ray emission, which are separated by a ~700 s long quiescent phase. Due to similar temporal shapes and spectra in the two episodes, GRB 220627A is speculated to be a gravitationally lensed gamma-ray burst (GRB). We analyze Fermi Large Area Telescope (LAT) data and find that about 49 gamma-ray photons above 100 MeV come from the GRB during the first episode, while there are no photons above 100 MeV in the second episode. Based on the broadband spectral study of the two episodes, the gravitationally lensing scenario can be ruled out at a high confidence level and we thus conclude that GRB 220627A is an intrinsically ultralong GRB with the prompt burst emission lasting longer than 1000 s. It is then the first case that GeV emission is detected from an ultralong GRB. We find that a short spike seen in the LAT light curve is also present in GBM detectors that see the burst, suggesting a common internal region of emission across the entire Fermi energy range. The detection of a 15.7 GeV photon during the early prompt phase places a lower limit of Γ ≥ 300 on the bulk Lorentz factor of the GRB ejecta. The constraint on the bulk Lorentz factor could shed light on the origin of ultralong GRBs.

Keywords: gamma-ray bursts; high energy astrophysics
Fast Multipole Method for Gravitational Lensing: Application to High-magnification Quasar Microlensing

We introduce the use of the fast multipole method (FMM) to speed up gravitational lensing ray tracing calculations. The method allows very fast calculation of ray deflections when a large number of deflectors, N *, are involved, while keeping rigorous control on the errors. In particular, we apply this method, in combination with the inverse polygon mapping (IPM) technique, to quasar microlensing to generate microlensing magnification maps with very high workloads (high magnification, large size, and/or high resolution) that require a very large number of deflectors. Using FMM-IPM, the computation time can be reduced by a factor of ~105 with respect to standard inverse ray shooting (IRS), making the use of this algorithm on a personal computer comparable to the use of standard IRS on GPUs. We also provide a flexible web interface for easy calculation of microlensing magnification maps using FMM-IPM (see https://gloton.ugr.es/microlensing/). We exemplify the power of this new method by applying it to some challenging interesting astrophysical scenarios, including clustered primordial black holes and extremely magnified stars close to the giant arcs of galaxy clusters. We also show the performance/use of FMM to calculate ray deflection for a halo resulting from cosmological simulations composed of a large number (N ≳ 107) of elements.

Keywords: quasar microlensing; gravitational lensing
Ultraviolet and Blue Optical Imaging of UVCANDELS

The UltraViolet Imaging of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey Fields (UVCANDELS) survey provided ultraviolet F275W imaging with coordinated parallel optical F435W imaging in four of the five CANDELS fields: GOODS-N, GOODS-S, EGS, and COSMOS, covering a total area of ~426 arcmin2. UVCANDELS takes primary WFC3/UVIS F275W exposures at a uniform 3-orbit depth and ACS F435W exposures (in parallel) at slightly varying depth due to the roll angle constraints and the overlap from the increased field of view of the ACS camera, reaching a limiting magnitude of ~27 and ~28 ABmag (5σ in 0.″2 apertures) for F275W and F435W, respectively. We present the results of the UVCANDELS observations, custom calibrations, and the creation of F275W and F435W imaging mosaics, which have been made publicly available on the Barbara A. Mikulski Archive for Space Telescopes.

Keywords: galaxy evolution; galaxy photometry; high-redshift galaxies; astronomical techniques
The Debiased Compositional Distribution of MITHNEOS: Global Match between the Near-Earth and Main-belt Asteroid Populations, and Excess of D-type Near-Earth Objects

We report 491 new near-infrared spectroscopic measurements of 420 near-Earth objects (NEOs) collected on the NASA InfraRed Telescope Facility as part of the MIT-Hawaii NEO Spectroscopic Survey. These measurements were combined with previously published data from Binzel et al. and bias-corrected to derive the intrinsic compositional distribution of the overall NEO population, as well as of subpopulations coming from various escape routes (ERs) in the asteroid belt and beyond. The resulting distributions reflect well the overall compositional gradient of the asteroid belt, with decreasing fractions of silicate-rich (S- and Q-type) bodies and increasing fractions of carbonaceous (B-, C-, D- and P-type) bodies as a function of increasing ER distance from the Sun. The close compositional match between NEOs and their predicted source populations validates dynamical models used to identify ERs and argues against any strong composition change with size in the asteroid belt between ~5 km and ~100 m. A notable exception comes from the overabundance of D-type NEOs from the 5:2J and, to a lesser extend, the 3:1J and ν 6 ERs, hinting at the presence of a large population of small D-type asteroids in the main belt. Alternatively, this excess may indicate preferential spectral evolution from D-type surfaces to C and P types as a consequence of space weathering, or point to the fact that D-type objects fragment more often than other spectral types in the NEO space. No further evidence for the existence of collisional families in the main belt, below the detection limit of current main-belt surveys, was found in this work.

Keywords: spectroscopy; asteroid surfaces; near-earth objects; main belt asteroids
Embedded Young Massive Star Clusters in the Antennae Merger

The properties of young massive clusters (YMCs) are key to understanding the star formation mechanism in starburst systems, especially mergers. We present Atacama Large Millimeter/submillimeter Array high-resolution (~10 pc) continuum (100 and 345 GHz) data of YMCs in the overlap region of the Antennae galaxy. We identify six sources in the overlap region, including two sources that lie in the same giant molecular cloud (GMC). These YMCs correspond well with radio sources in lower-resolution continuum (100 and 220 GHz) images at GMC scales (~60 pc). We find most of these YMCs are bound clusters through virial analysis. We estimate their ages to be ~1 Myr and that they are either embedded or just beginning to emerge from their parent cloud. We also compare each radio source with a Paβ source, and find they have consistent total ionizing photon numbers, which indicates they are tracing the same physical source. By comparing the free-free emission at ~10 pc scale and ~60 pc scale, we find that ~50% of the free-free emission in GMCs actually comes from these YMCs. This indicates that roughly half of the stars in massive GMCs are formed in bound clusters. We further explore the mass correlation between YMCs and GMCs in the Antennae and find it generally agrees with the predictions of the star cluster simulations. The most massive YMC has a stellar mass that is 1%-5% of its host GMC mass.

Keywords: interstellar medium; starburst galaxies; star clusters; star formation
In the Trenches of the Solar-Stellar Connection. VI. Total EclipSS

The Ecliptic poles Stellar Survey (EclipSS; 2018-2019) collected Hubble Space Telescope/Cosmic Origins Spectrograph (COS) 1150-1420 Å spectra of 49 FGK dwarfs at high ecliptic latitudes. These regions are favored by the scanning programs of the Transiting Exoplanet Survey Satellite (TESS; high-precision optical light curves) and Extended Roentgen Survey with an Imaging Telescope Array (eROSITA; repeated X-ray visits over half a decade), which can provide vital ancillary support in the exploration of high-energy "stellar activity." The present study is a follow-on, focused on new Chandra/High Resolution Camera 0.1-2.4 keV X-ray pointings, COS 1340-1720 Å spectra, and TESS photometry of the 10 most active EclipSS members, but also including archival X-ray and far-ultraviolet (FUV) observations of 13 representative solar neighborhood FGK dwarfs, together with high-energy irradiances of the Sun, for context. The EclipSS dK+dM binary HD 41004 proved exceptional. The unexpectedly short TESS period (1.3 days) appears to be associated with the red dwarf secondary, possibly about to engulf a close-orbiting brown-dwarf companion. The current study describes the emission-line profiles of a high-resolution subset of the full sample, finding the non-Gaussian line shapes (sharper peaks, broader wings) and redshifts of T ~ 105 K features to be remarkably independent of activity; quantifies X-ray and FUV "variability bias" based on several multiple-epoch campaigns; builds enhanced flux-flux diagrams (e.g., X-rays versus C IV); and constructs an "XUV" proxy flux, representing the total coronal radiative loss, to test models of the convective turnover time, τ c. The associated Rossby number, Ro, is closely aligned to terrestrial and cosmic magnetic dynamo theories, and offers the prospect of a one-parameter description of stellar high-energy activity (relevant, for example, to host-star ionizing fluxes impacting exoplanets).

Keywords: x-ray stars; stellar spectral lines; stellar rotation; stellar activity; ultraviolet sources