Sazuna/UAT_keywords huggingface dataset:
Insight-HXMT, NICER, and NuSTAR Views to the Newly Discovered Black Hole X-Ray Binary Swift J151857.0–572147. The systematic properties are largely unknown for the black hole X-ray binary Swift J151857.0–572147 newly discovered in the 2024 outburst. The nature of a black hole can be completely defined by specifying the mass and dimensionless spin parameter. Therefore, accurate measurement of the two fundamental parameters is important for understanding the nature of black holes. The joint spectral fitting of a reflection component with simultaneous observations from Insight-HXMT, NICER, and NuSTAR reveals for the first time a black hole dimensionless spin of  0.84‑0.26+0.17  and an inclination angle of  21.1‑3.6+4.5  degrees for this system. Monitoring of the soft state by NICER results in disk flux and temperature following  Fdisk∝Tin3.83±0.17 . For the standard thin disk,  Ldisk≈4πRin2σTin4 , so the relationship between the flux and temperature of the disk we measured indicates that the inner radius of the disk is stable and the disk is in the innermost stable circular orbit. With an empirical relation built previously between the black hole outburst profile and the intrinsic power output, the source distance is estimated as 5.8 ± 2.5 kpc according to the outburst profile and peak flux observed by Insight-HXMT and NICER. Finally, a black hole mass of 3.67 ± 1.79–8.07 ± 4.20M ⊙ can be inferred from a joint diagnostic of the aforementioned parameters measured for this system. This system is also consistent with most black hole X-ray binaries with high spin and a mass in the range of 5–20 M ⊙.

Keywords: X-ray binary stars
JWST Thermal Emission of the Terrestrial Exoplanet GJ 1132b. We present thermal emission measurements of GJ 1132b spanning 5–12 μm obtained with the Mid-Infrared Instrument Low-Resolution Spectrometer on the James Webb Space Telescope. GJ 1132b is an M dwarf rocky planet with T eq = 584 K and an orbital period of 1.6 days. We measure a white-light secondary eclipse depth of 140 ± 17 ppm, which corresponds to a dayside brightness temperature of T  p,dayside = 709 ± 31 K using improved star and planet parameters. This measured temperature is only 1σ below the maximum possible dayside temperature of a bare rock (i.e., assuming a zero-albedo planet with no heat redistribution,  Tmax  =  746‑11+14  K). The emission spectrum is consistent with a featureless blackbody, which agrees with a wide range of possible surface compositions. By comparing forward models to the dayside emission spectrum, we rule out Earth-thickness (P ∼ 1 bar) atmospheres with at least 1% H2O, atmospheres of any modeled thickness (10‑4 to 102 bars) that contain at least 1% CO2, and thick, Venus-like atmospheres (P ≳ 100 bars) with at least 1 ppm CO2 or H2O. We therefore conclude that GJ 1132b likely does not have a significant atmosphere. This finding supports the concept of a universal "cosmic shoreline" given the high level of bolometric and extreme ultraviolet (EUV) and X-rays (collectively XUV) irradiation received by the planet.

Keywords: Interdisciplinary astronomy, Exoplanet atmospheric composition , Exoplanet surface composition, Exoplanet astronomy, Astrobiology, Exoplanet surface characteristics, Biosignatures, Exoplanet atmospheres
Tidal Disruption Events from Stripped Stars. Observations of tidal disruption events (TDEs) show signs of nitrogen enrichment reminiscent of other astrophysical sources such as active galactic nuclei and star-forming galaxies. Given that TDEs probe the gas from a single star, it is possible to test whether the observed enrichment is consistent with expectations from the CNO cycle by looking at the observed nitrogen/carbon (N/C) abundance ratios. Given that ≈20% of solar-mass stars (and an even larger fraction of more massive stars) live in close binaries, it is worthwhile to also consider what TDEs from stars influenced by binary evolution would look like. We show here that TDEs from stars stripped of their hydrogen-rich (and nitrogen-poor) envelopes through previous binary-induced mass loss can produce much higher observable N/C enhancements than even TDEs from massive stars. Additionally, we predict that the time dependence of the N/C abundance ratio in the mass fallback rate of stripped stars will follow the inverse behavior of main-sequence stars, enabling a more accurate characterization of the disrupted star.

Keywords: Supermassive black holes, Binary stars, High energy astrophysics, Broad-absorption line quasar, Close binary stars, Carbon-nitrogen cycle, Tidal disruption, Transient sources, Galaxy nuclei, X-ray transient sources, Active galactic nuclei, Ultraviolet transient sources
Photospheric Pore Rotation Associated with a C-class Flare from Spectropolarimetric Observations with DKIST. We present high-resolution observations of a C4.1-class solar flare (SOL2023-05-03T20:53) in AR 13293 from the Visible Spectro-Polarimeter (ViSP) and Visible Broadband Imager (VBI) instruments at the DKIST. The fast cadence, good resolution, and high polarimetric sensitivity of ViSP data provide a unique opportunity to explore the photospheric magnetic fields before and during the flare. We infer the magnetic field vector in the photosphere from the Fe I 6302 Å line using Milne–Eddington inversions. Combined analysis of the inverted data and VBI images reveals the presence of two opposite polarity pores exhibiting rotational motion both prior to and throughout the flare event. Data-driven simulations further reveal a complex magnetic field topology above the rotating pores, including a null-point-like configuration. We observed a 30% relative change in the horizontal component (δ F  h ) of Lorentz force at the flare peak time and roughly no change in the radial component. We find that the changes in δ F  h  are the most likely driver of the observed pore rotation. These findings collectively suggest that the back reaction of magnetic field line reconfiguration in the corona may influence the magnetic morphology and rotation of pores in the photosphere on a significantly smaller scale.

Keywords: Spectropolarimetry, Solar flares
The MIRI Exoplanets Orbiting White dwarfs (MEOW) Survey: Mid-infrared Excess Reveals a Giant Planet Candidate around a Nearby White Dwarf. The MIRI Exoplanets Orbiting White dwarfs survey is a cycle 2 JWST program to search for exoplanets around dozens of nearby white dwarfs via infrared excess and direct imaging. In this Letter, we present the detection of mid-infrared excess at 18 and 21 μm toward the bright (V = 11.4) metal-polluted white dwarf WD 0310–688. The source of the IR excess is almost certainly within the system; the probability of background contamination is &lt;0.1%. While the IR excess could be due to an unprecedentedly small and cold debris disk, it is best explained by a  3.0‑1.9+5.5  M Jup cold (248 ‑61+84  K) giant planet orbiting the white dwarf within the forbidden zone (the region where planets are expected to be destroyed during the star's red giant phase). We constrain the source of the IR excess to an orbital separation of 0.1–2 au, marking the first discovery of a white dwarf planet candidate within this range of separations. WD 0310–688 is a young remnant of an A- or late B-type star, and at just 10.4 pc, it is now the closest white dwarf with a known planet candidate. Future JWST observations could distinguish the two scenarios by either detecting or ruling out spectral features indicative of a planet atmosphere.

Keywords: Exoplanet migration, White dwarf stars, Infrared excess, Debris disks, Extrasolar gaseous giant planets
A Hide-and-seek Game: Looking for Population III Stars during the Epoch of Reionization through the He II λ1640 Line. The gas surrounding first-generation (Population III, hereafter Pop III) stars is expected to emit a distinct signature in the form of the He II recombination line at 1640 Å(He II λ1640). Here we explore the challenges and opportunities in identifying this elusive stellar population via the He II λ1640 in M ⋆ &gt; 107.5 M ⊙ galaxies during the Epoch of Reionization (z ≃ 6–10), using JWST/NIRSpec. With this aim in mind, we combine cosmological dustyGadget simulations with analytical modeling of the intrinsic He II emission. While tentative candidates with bright He II emission like GN-z11 have been proposed in the literature, the prevalence of such bright systems remains unclear due to significant uncertainties involved in the prediction of the He II luminosity. In fact, similar Pop III clumps might be almost 2 orders of magnitude fainter, primarily depending on the assumed Pop III formation efficiency and initial mass function in star-forming clouds, while the effect of stellar mass loss is responsible for a factor of order unity. Moreover, up to ∼90% of these clumps might be missed with NIRSpec multi-object spectroscopy due to the limited field of view, while this problem appears to be less severe with NIRSpec's integral field unit. We investigate the potential of deep spectroscopy targeting peripheral Pop III clumps around bright, massive galaxies to achieve a clear detection of the first stars.

Keywords: Early universe, Hydrodynamical simulations, Population III stars, Theoretical models, James Webb Space Telescope, Reionization, Galaxy spectroscopy, High-redshift galaxies
The Dark Energy Survey: Cosmology Results with ∼1500 New High-redshift Type Ia Supernovae Using the Full 5 yr Data Set. We present cosmological constraints from the sample of Type Ia supernovae (SNe Ia) discovered and measured during the full 5 yr of the Dark Energy Survey (DES) SN program. In contrast to most previous cosmological samples, in which SNe are classified based on their spectra, we classify the DES SNe using a machine learning algorithm applied to their light curves in four photometric bands. Spectroscopic redshifts are acquired from a dedicated follow-up survey of the host galaxies. After accounting for the likelihood of each SN being an SN Ia, we find 1635 DES SNe in the redshift range 0.10 &lt; z &lt; 1.13 that pass quality selection criteria sufficient to constrain cosmological parameters. This quintuples the number of high-quality z &gt; 0.5 SNe compared to the previous leading compilation of Pantheon+ and results in the tightest cosmological constraints achieved by any SN data set to date. To derive cosmological constraints, we combine the DES SN data with a high-quality external low-redshift sample consisting of 194 SNe Ia spanning 0.025 &lt; z &lt; 0.10. Using SN data alone and including systematic uncertainties, we find ΩM = 0.352 ± 0.017 in flat ΛCDM. SN data alone now require acceleration (q 0 &lt; 0 in ΛCDM) with over 5σ confidence. We find   in flat wCDM. For flat w 0 w  a CDM, we find  , consistent with a constant equation of state to within ∼2σ. Including Planck cosmic microwave background, Sloan Digital Sky Survey baryon acoustic oscillation, and DES 3 × 2pt data gives (ΩM, w) = (0.321 ± 0.007, −0.941 ± 0.026). In all cases, dark energy is consistent with a cosmological constant to within ∼2σ. Systematic errors on cosmological parameters are subdominant compared to statistical errors; these results thus pave the way for future photometrically classified SN analyses.

Keywords: Cosmology, Type Ia supernovae, Dark matter, Dark energy
The Stellar Distribution in Ultrafaint Dwarf Galaxies Suggests Deviations from the Collisionless Cold Dark Matter Paradigm. Unraveling the nature of dark matter (DM) stands as a primary objective in modern physics. Here we present evidence suggesting deviations from the collisionless cold DM (CDM) paradigm. It arises from the radial distribution of stars in six ultrafaint dwarf (UFD) galaxies measured with the Hubble Space Telescope. After a trivial renormalization in size and central density, the six UFDs show the same stellar distribution, which happens to have a central plateau or core. Assuming spherical symmetry and isotropic velocities, the Eddington inversion method proves the observed distribution to be inconsistent with the characteristic potentials of CDM particles. Under such assumptions, the observed innermost slope of the stellar profile discards the UFDs to reside in a CDM potential at a ≥97% confidence level. The extremely low stellar mass of these galaxies, 103–104 M ⊙, prevents stellar feedback from modifying the shape of a CDM potential. Other conceivable explanations for the observed cores, like deviations from spherical symmetry and isotropy, tidal forces, and the exact form of the used CDM potential, are disfavored by simulations and/or observations. Thus, the evidence suggests that collisions among DM particles or other alternatives to CDM are likely shaping these galaxies. Many of these alternatives produce cored gravitational potentials, shown here to be consistent with the observed stellar distribution.

Keywords: Dark matter distribution, Cold dark matter, Dwarf galaxies, Star counts, Dark matter
Evidence for Dust Depletion in a Misaligned Protoplanetary Disk with JWST. Here we report the detection of dust depletion in a misaligned inner disk around UX Tau A using JWST MIRI spectra. Mid-infrared (MIR) continuum "seesaw" variability was detected in this disk by Spitzer and attributed to variable shadows cast on the outer disk by the inner disk. The JWST MIRI spectrum of UX Tau A also shows seesaw variability but with a significant decrease of emission shortward of 10 μm to nearly photospheric levels. We argue that UX Tau A's MIR continuum variability is due to depletion of dust in a misaligned inner disk. We speculate that this dust depletion occurs because the inner disk is misaligned from the outer disk, which can disrupt the replenishment of the inner disk from the outer disk. Using contemporaneous measurements of the mass accretion rate of UX Tau A and estimating the amount of dust necessary to produce the MIR excess in the Spitzer observations, we estimate a minimum dust depletion timescale of ∼0.1 yr. These observations show that we can indirectly detect the signatures of misaligned inner disks through MIR continuum variability and that in some cases the inner disk may be significantly depleted of dust and become optically thin.

Keywords: Protoplanetary disks, Classical T Tauri stars
Implication of Jet Physics from MeV Line Emission of GRB 221009A. Ultrarelativistic jets are believed to play an important role in producing prompt emission and afterglow of gamma-ray bursts (GRBs), but the nature of the jet is poorly known owing to the lack of decisive features observed in the prompt emission. The discovery of an emission line evolving from about 37 to 6 MeV in the brightest-of-all-time GRB 221009A provides an unprecedented opportunity to probe GRB jet physics. The time evolution of the central energy of the line with power-law index ‑1 is naturally explained by the high-latitude curvature effect. Under the assumption that the line emission is generated in the prompt emission by e ± pair production, cooling, and annihilation in the jet, we can strictly constrain jet physics with observed line emission properties. We find that the radius of the emission region is r ≳ 1016 cm. The narrow line width of ∼10% requires that the line emission occurs within 10% of the dynamical time, which further implies short timescales of pair cooling to the nonrelativistic state and pair annihilation, as well as a slightly clumpy emission region. If the jet's Lorentz factor is Γ ≳ 400, the fast cooling requirement needs an energy density of magnetic field in the jet much larger than that of prompt gamma rays, i.e., a magnetically dominated jet. The temporal behavior of line flux suggests some angle dependence of line emission. We also discuss the difficulties of other scenarios for the observed emission line.

Keywords: Gamma-ray bursts, Relativistic jets, Gamma-ray lines
Solar Atmospheric Oscillations as Measured by the GOES-R Series EXIS EUVS-C Instrument. This Letter presents first observations of distinct solar atmospheric oscillations from signals collected by the Extreme Ultraviolet and X-ray Irradiance Sensors EUVS-C instrument, which is part of each Geostationary Observational Environmental Satellite R-Series instrument payload. The EUVS-C instrument is a full-disk, normal-incidence spectrograph that covers a narrow band in the mid-ultraviolet between 276 and 284 nm, where it can measure the magnesium II emission doublet at ∼280 nm and the photospheric continuum. The primary goal of EUVS-C data is to construct the well-known Mg II index, which is often used as a proxy for chromospheric activity. Because of the high temporal and spectral resolution of EUVS-C measurements, the data provide a unique opportunity to observe discernible solar atmospheric waves that have definite signatures of 3 and 5 minute oscillation periods, where the frequency response of these signals is dependent on what part of the spectrum is analyzed (e.g., Mg emission lines). Furthermore, both photospheric and chromospheric waves can simultaneously be examined. With the recent increase in solar activity for Solar Cycle 25, these waves exhibit enhanced amplitudes and phase shifts during the impulsive shock of strong solar flares. This Letter will discuss the analysis for deriving these waves, and results from both a quiescent Sun and an X-class solar flare event will be presented.

Keywords: Solar oscillations, Solar atmospheric motions, Remote sensing
Magnetically Arrested Circumbinary Accretion Flows. Binary systems with comparable masses and a surrounding accretion disk can accrete gas through spiral accretion streams penetrating the central cavity formed by tidal interactions. Using three-dimensional Newtonian magnetohydrodynamics simulations, we investigate the possibility of a magnetically arrested accretion flow through the cavity. Rather than solely continuously feeding the binary through spiral accretion streams, the accretion is regulated by the strong magnetic field inside the cavity. Transport of mass and angular momentum onto the binary then proceeds largely periodically in magnetic flux eruption episodes. The ejected flux tubes carry angular momentum outward and away from the binary, inject hot plasma into the disk, and can launch flares. This likely intermittent scenario could have potential implications for the emission signatures of supermassive black hole binaries and shed light onto the role magnetic fields play in the binary's orbital evolution.

Keywords: Accretion, Magnetohydrodynamics, Black holes, Circumstellar disks, Astronomical simulations, Magnetohydrodynamical simulations
The Origin of the Coherent Radio Flash Potentially Associated with GRB 201006A. Rowlinson et al. recently claimed the detection of a coherent radio flash 76.6 minutes after a short gamma-ray burst (GRB). They proposed that the radio emission may be associated with a long-lived neutron star engine. We show through theoretical and observational arguments that the coherent radio emission, if real and indeed associated with GRB 201006A and at the estimated redshift, is unlikely to be due to the collapse of the neutron star, ruling out a blitzar-like mechanism. Instead, we show if a long-lived engine was created, it must have been stable with the radio emission likely linked to the intrinsic magnetar activity. However, we find that the optical upper limits require fine-tuning to be consistent with a magnetar-driven kilonova: we show that neutron-star engines that do satisfy the optical constraints would have produced a bright kilonova afterglow that should already be observable by the Very Large Array or MeerKAT (for ambient densities typical for short GRBs). Given the optical limits and the current lack of a kilonova afterglow, we instead posit that no neutron star survived the merger, and the coherent radio emission was produced far from a black hole central engine via mechanisms such as synchrotron maser or magnetic reconnection in the jet—a scenario consistent with all observations. We encourage future radio follow-up to probe the engine of this exciting event and continued prompt radio follow-up of short GRBs.

Keywords: Neutron stars, Gamma-ray bursts, Radio transient sources
Single-star Warm-Jupiter Systems Tend to Be Aligned, Even around Hot Stellar Hosts: No T <SUB>eff</SUB>–λ Dependency. The stellar obliquity distribution of warm-Jupiter systems is crucial for constraining the dynamical history of Jovian exoplanets, as the warm Jupiters' tidal detachment likely preserves their primordial obliquity. However, the sample size of warm-Jupiter systems with measured stellar obliquities has historically been limited compared to that of hot Jupiters, particularly in hot-star systems. In this work, we present newly obtained sky-projected stellar obliquity measurements for the warm-Jupiter systems TOI-559, TOI-2025, TOI-2031, TOI-2485, TOI-2524, and TOI-3972, derived from the Rossiter–McLaughlin effect, and show that all six systems display alignment with a median measurement uncertainty of 13°. Combining these new measurements with the set of previously reported stellar obliquity measurements, our analysis reveals that single-star warm-Jupiter systems tend to be aligned, even around hot stellar hosts. This alignment exhibits a 3.4σ deviation from the T eff–λ dependency observed in hot-Jupiter systems, where planets around cool stars tend to be aligned, while those orbiting hot stars show considerable misalignment. The current distribution of spin–orbit measurements for Jovian exoplanets indicates that misalignments are neither universal nor primordial phenomena affecting all types of planets. The absence of misalignments in single-star warm-Jupiter systems further implies that many hot Jupiters, by contrast, have experienced a dynamically violent history. *This Letter includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

Keywords: Exoplanet dynamics, Planetary theory, Exoplanets, Planetary alignment, Hot Jupiters, Exoplanet systems, Exoplanet astronomy, Exoplanet evolution, Star-planet interactions, Planetary dynamics
Climate Bistability at the Inner Edge of the Habitable Zone due to Runaway Greenhouse and Cloud Feedbacks. Understanding the climate dynamics at the inner edge of the habitable zone is crucial for predicting the habitability of rocky exoplanets. Previous studies using global climate models (GCMs) have indicated that planets receiving high stellar flux can exhibit climate bifurcations, leading to bistability between a cold (temperate) and a hot (runaway) climate. However, the mechanism causing this bistability has not been fully explained, in part due to the difficulty associated with inferring mechanisms from small numbers of expensive numerical simulations in GCMs. In this study, we employ a two-column (dayside and nightside), two-layer climate model to investigate the physical mechanisms driving this bistability. Through mechanism-denial experiments, we demonstrate that the runaway greenhouse effect, coupled with a cloud feedback on either the dayside or nightside, leads to climate bistability. We also map out the parameters that control the location of the bifurcations and size of the bistability. This work identifies which mechanisms and GCM parameters control the stellar flux at which rocky planets are likely to retain a hot, thick atmosphere if they experience a hot start. This is critical for the prioritization of targets and interpretation of observations by the James Webb Space Telescope. Furthermore, our modeling framework can be extended to planets with different condensable species and cloud types.

Keywords: Extrasolar rocky planets, Exoplanet atmospheric composition , Water vapor, Exoplanets, Planetary atmospheres, Habitable planets, Exoplanet atmospheres, Atmospheric science