Sazuna/UAT_keywords huggingface dataset:
RUBIES: JWST/NIRSpec Confirmation of an Infrared-luminous, Broad-line Little Red Dot with an Ionized Outflow. The JWST discovery of "little red dots" (LRDs) is reshaping our picture of the early Universe, yet the physical mechanisms driving their compact size and UV-optical colors remain elusive. Here, we report an unusually bright LRD (zspec = 3.1) observed as part of the RUBIES program. This LRD exhibits broad emission lines (FWHM ∼ 4000 km s‑1), a blue UV continuum, a clear Balmer break, and a red continuum sampled out to rest-frame 4 μm with MIRI. We develop a new joint galaxy and active galactic nucleus (AGN) model within the Prospector Bayesian inference framework and perform spectrophotometric modeling using NIRCam, MIRI, and NIRSpec/Prism observations. Our fiducial model reveals a M* ∼ 109 M⊙ galaxy alongside a dust-reddened AGN driving the optical emission. Explaining the rest-frame optical color as a reddened AGN requires AV ≳ 3, suggesting that a great majority of the accretion disk energy is reradiated as dust emission. Yet, despite clear AGN signatures, we find a surprising lack of hot torus emission, which implies that either the dust emission in this object must be cold, or the red continuum must instead be driven by a massive, evolved stellar population of the host galaxy—seemingly inconsistent with the high-EW broad lines (Hα rest-frame EW ∼ 800 Å). The widths and luminosities of Pa-β, Pa-δ, Pa-γ, and Hα imply a modest black hole mass of MBH ∼ 108 M⊙. Additionally, we identify a narrow blueshifted He I λ 1.083 μm absorption feature in NIRSpec/G395M spectra, signaling an ionized outflow with kinetic energy up to ∼1% the luminosity of the AGN. The low redshift of RUBIES-BLAGN-1, combined with the depth and richness of the JWST imaging and spectroscopic observations, provides a unique opportunity to build a physical model for these so-far mysterious LRDs, which may prove to be a crucial phase in the early formation of massive galaxies and their supermassive black holes.

Keywords: AGN host galaxies, Galaxy formation, Photoionization, Active galactic nuclei, Galaxy kinematics, Spectral energy distribution
The Redshift Evolution of the M<SUB>BH</SUB>–M<SUB>*</SUB> Scaling Relation: New Insights from Cosmological Simulations and Semianalytic Models. We study the coevolution of black holes (BHs) and their host galaxies in the ASTRID and TNG300 cosmological simulations and the DARK SAGE semianalytic model (SAM), focusing on the evolution of the BH mass–stellar mass (MBH–M*) relation. Due to differences in the adopted subgrid modeling of BH seeding, dynamics, and feedback, the models differ in their predicted redshift evolution of the MBH–M* relation. We find that it is the interplay between the star formation rate (SFR) and the black hole accretion rate (BHAR) that drives the evolution of the mean relation. We define a quantity  , the ratio between the specific BHAR and SFR (i.e.,  sBHAR/sSFR), and demonstrate that it is   that governs the evolution of individual sources in the MBH–M* plane. The efficiency of BH growth versus stellar mass growth in the sSFR–sBHAR plane reflects the partitioning of gas between fueling star formation versus BH accretion. This partitioning depends on the implementation of BH dynamics and the nature of how black hole feedback quenches galaxies. In the cosmological simulations (ASTRID and TNG300), the BHAR and SFR are intrinsically linked, resulting in a tight MBH–M* correlation, while the DARK SAGE SAM produces a significantly larger scatter. We discuss these results in the context of recently discovered overmassive BHs and massive quenched galaxies at high redshift by the James Webb Space Telescope.

Keywords: Supermassive black holes, Galaxy evolution
The Distribution of Ultrahigh-energy Cosmic Rays along the Supergalactic Plane Measured at the Pierre Auger Observatory. Ultrahigh-energy cosmic rays are known to be mainly of extragalactic origin, and their propagation is limited by energy losses, so their arrival directions are expected to correlate with the large-scale structure of the local Universe. In this work, we investigate the possible presence of intermediate-scale excesses in the flux of the most energetic cosmic rays from the direction of the supergalactic plane region using events with energies above 20 EeV recorded with the surface detector array of the Pierre Auger Observatory up to 2022 December 31, with a total exposure of 135,000 km2 sr yr. The strongest indication for an excess that we find, with a posttrial significance of 3.1σ, is in the Centaurus region, as in our previous reports, and it extends down to lower energies than previously studied. We do not find any strong hints of excesses from any other region of the supergalactic plane at the same angular scale. In particular, our results do not confirm the reports by the Telescope Array Collaboration of excesses from two regions in the Northern Hemisphere at the edge of the field of view of the Pierre Auger Observatory. With a comparable integrated exposure over these regions, our results there are in good agreement with the expectations from an isotropic distribution.

Keywords: Cosmic anisotropy, Ultra-high-energy cosmic radiation, Cosmic rays
Rapidly Varying Ionization Features in a Quasi-periodic Eruption: A Homologous Expansion Model for the Spectroscopic Evolution. Quasi-periodic eruptions (QPEs) are recurring bursts of soft X-ray emission from supermassive black holes, which a growing class of models explains via extreme mass ratio inspirals (EMRIs). QPEs exhibit blackbody-like emission with significant temperature evolution, but the minimal information content of their almost pure-thermal spectra has limited physical constraints. Here we study the recently discovered QPEs in ZTF19acnskyy ("Ansky"), which show absorption-like features evolving dramatically within eruptions and correlating strongly with continuum temperature and luminosity, further probing the conditions underlying the emission surface. The absorption features are well described by dense ionized plasma of column density NH ≳ 1021 cm‑2, blueshift 0.06 ≲ v/c ≲ 0.4, and either collisional or photoionization equilibrium. With high-resolution spectra, we also detect ionized blueshifted emission lines suggesting a nitrogen overabundance of  solar. We interpret our results with orbiter–disk collisions in an EMRI system, in which each impact drives a shock that locally heats the disk and expels X-ray-emitting debris undergoing radiation-pressure-driven homologous expansion. We explore an analytical toy model that links the rapid change in absorption lines to the evolution of the ionization parameter and the photosphere radius, and we suggest that ∼10‑3 M⊙ ejected per eruption with expansion velocities up to   can reproduce the absorption features. With these assumptions, we show that a P Cygni profile in a spherical expansion geometry qualitatively matches the observed line profiles. Our work takes a first step toward extending existing physical models for QPEs to address their implications for spectral line formation.

Keywords: X-ray astronomy, Supermassive black holes, High energy astrophysics
K Dwarf Radius Inflation and a 10 Gyr Spin-down Clock Unveiled through Asteroseismology of HD 219134 from the Keck Planet Finder. We present the first asteroseismic analysis of the K3 V planet host HD 219134 based on four consecutive nights of radial velocities collected with the Keck Planet Finder. We apply Gold deconvolution to the power spectrum to disentangle modes from side lobes in the spectral window and extract 25 mode frequencies with spherical degrees 0 ≤ ℓ ≤ 3. We derive the fundamental properties using five different evolutionary-modeling pipelines and report a mass of 0.763 ± 0.020 (stat) ± 0.007 (sys) M⊙, a radius of 0.748 ± 0.007 (stat) ± 0.002 (sys) R⊙, and an age of 10.151 ± 1.520 (stat) ± 0.810 (sys) Gyr. Compared to the interferometric radius 0.783 ± 0.005 R⊙, the asteroseismic radius is 4% smaller at the 4σ level—a discrepancy not easily explained by known interferometric systematics, modeling assumptions on atmospheric boundary conditions and mixing lengths, magnetic fields, or tidal heating. HD 219134 is the first main-sequence star cooler than 5000 K with an asteroseismic age estimate and will serve as a critical calibration point for stellar spin-down relations. We show that existing calibrated prescriptions for angular momentum loss, incorporating weakened magnetic braking with asteroseismically constrained stellar parameters, accurately reproduce the observed rotation period. Additionally, we revised the masses and radii of the super-Earths in the system, which support their having Earth-like compositions. Finally, we confirm that the oscillation amplitude in radial velocity scales as (L/M)1.5 in K dwarfs, in contrast to the (L/M)0.7 relation observed in G dwarfs. These findings provide significant insights into the structure and angular momentum loss of K-type stars.

Keywords: K dwarf stars, Stellar rotation, Stellar oscillations
The Nature of Spectral Variability of the Accreting Pulsar Centaurus X-3 Unveiled by NuSTAR Observation Covering Two Orbital Cycles. We conducted a 369 ks NuSTAR observation on the X-ray pulsar Centaurus X-3, which covered two consecutive orbital cycles of the source, including two eclipse durations. We investigated the orbital-phase spectral variability over the two orbital cycles. We divided the entire observation data into multiple segments, each covering an orbital interval of ΔΦ = 0.005. The phenomenological spectral modeling applied to these orbital-phase-resolved spectra reveals that the photon index is the key parameter with the most variability and a strong correlation with the continuum flux. The photon index becomes softer during the high-flux phases and harder in the low-flux phases. The relation between the photon index and continuum flux remains consistent when investigating specific spin phases, suggesting that the spectral variability originates from extrinsic factors apart from the neutron star. Furthermore, the 3–5 keV pulse fraction also exhibits variability, being enhanced in the high-flux phases and suppressed in the low-flux phases, which indicates the presence of multiple emission components with different pulse fractions. These phenomenological analysis results enabled us to estimate the physical origin of the spectral variability. We successfully fitted the orbital-phase-resolved spectra with a physical model that assumes (1) stable emission from the neutron star, (2) attenuation by inhomogeneous, clumpy stellar wind, and (3) an additional nonpulsed emission component arising from thermal emission from the accretion disk. The thermal emission from the accretion disk can be described by a blackbody with a temperature of kT ∼ 0.5 keV and a luminosity of ∼1037 erg s‑1.

Keywords: Accretion, Neutron stars, X-ray binary stars, Binary pulsars
Flat Circular Velocities on a Megaparsec Scale from the ΛCDM Model. A recent study using weak gravitational lensing reveals that there are some isolated galaxies with almost flat rotation curves at very large distances from the galactic centers. According to the authors of the study, this provides a strong challenge to the standard cold dark matter model, since the dark haloes are too small to explain their observations, especially for small stellar masses. In this article, we show that by improving their model, the virial radius is larger than their estimates. The Navarro–Frenk–White rotational curve, and especially the pseudo-isothermal one, are in agreement with their flat rotational curves, especially for the larger baryonic mass bins used by the authors.

Keywords: Dark matter
Monitoring the Dust Emission from R Aqr with SOFIA: Eclipse and Periastron Passage. We present infrared (IR) spectra from our monitoring of the symbiotic Mira, R Aquarii, using the Stratospheric Observatory for Infrared Astronomy. New mid-IR photometric and spectroscopic observations using the FORCAST instrument were obtained in 2022 September, when the system was well into the eclipse phase. The 10 μm silicate feature has increased in strength since the previous observations, obtained in 2019 October. Radiative transfer models of the emission show that the dust density has increased by a factor of about 2 in this period. Three epochs of far-IR photometric observations obtained with the HAWC+ instrument between 2018 July and 2020 September are also presented here. The emission at the sampled wavelength bands ranging from 53 to 214 μm does not vary significantly, in contrast to the mid-IR silicate dust emission that shows large variations. The models suggest that the far-IR emission arises much further out in the circumstellar dust shell and is not affected by the dynamics in the inner regions that impact the mid-IR emission.

Keywords: Symbiotic binary stars, Circumstellar dust, Asymptotic giant branch, Stellar pulsations
The Impact of Interplanetary Magnetic Field Intensity on the Escape of Heavy Ions from the Martian Magnetotail. The interplanetary magnetic field (IMF) is one of the primary factors influencing the Martian plasma environment. In this study, a multifluid magnetohydrodynamic model is adopted to investigate how variations in IMF affect planetary ion escape, particularly the tailward escape flux. Our results reveal that for nominal IMF direction (  Parker spiral), as IMF intensity increases, the ion escape rate decreases considerably. This reduction is primarily due to the decrease in planetary ion density in the plume and the magnetotail, which is caused by the lower ion production rate through the charge exchange process under high IMF conditions. With high IMF conditions, the dynamo at the bow shock is significantly enhanced, leading to a more severe deceleration of solar wind protons and fewer protons entering the magnetosheath. Consequently, intensified electromagnetic fields create a stronger induced magnetosphere, which shields the Martian ionosphere and atmosphere. Although the enhanced loading process for planetary ions results in higher ion escape velocities, the overall ion escape fluxes decrease due to the significant reduction in planetary ion density.

Keywords: Planetary magnetospheres, Mars, Interplanetary magnetic fields, Magnetohydrodynamics
A Phase-resolved View of Millihertz Quasiperiodic Oscillations in the Ultraluminous X-Ray Source M51 ULX-7: Evidence for a Magnetically Truncated Disk and Geometrical Beaming. X-ray quasiperiodic oscillations (QPOs) are commonly observed in Galactic X-ray binaries and extragalactic ultraluminous X-ray sources (ULXs). In this study, we perform a phase-resolved analysis of recently discovered X-ray mHz QPOs in M51 ULX-7. This represents the first detailed phase-resolved analysis of QPOs conducted in ULXs. Our findings reveal that the amplitude of the mHz QPO slightly increases with photon energy, accompanied by a narrowing of the phase modulation profile. The phase-resolved spectroscopy indicates significant variability in the energy spectrum: both disk blackbody components exhibit marked variations on the QPO timescale, with the low-temperature component demonstrating significant synchronous changes in the disk temperature and luminosity, showing a positive correlation between these two parameters throughout the QPO cycle. This correlation supports the hypothesis that the disk inner radius corresponds to the magnetospheric radius, which slightly varies with the accretion rate. Our results suggest that the soft component, without beaming, originates from a magnetically truncated outer disk, while the hard component is geometrically beamed from the inner funnel regions.

Keywords: Accretion, Neutron stars, Ultraluminous x-ray sources, Pulsars
Solar Wind Control of the Martian Magnetotail Current Sheet and Magnetic Reconnection. Magnetic reconnection is a rapid process that releases magnetic free energy stored in current sheets (CSs), driving various explosive phenomena throughout the Universe. In planets within the solar system, reconnection is controlled by both the solar wind and the planet's magnetic field and rotation. In this study, we perform a statistical analysis of the characteristics of CSs and reconnection events in the Martian magnetotail, considering varying solar wind conditions and local crustal field variations. The results show that higher solar wind dynamic pressure leads to a significantly increased probability of reconnection, primarily due to the enhanced cross-tail current density. In contrast, the orientation of interplanetary magnetic fields and local crustal anomalies predominantly affect the spatial distribution of CSs and reconnection events. Moreover, high solar wind dynamic pressure significantly enhances the average tailward flux of hydrogen and oxygen ions, likely attributable to the enhanced pickup of planetary ions.

Keywords: Planetary magnetospheres, Mars, Solar-planetary interactions, Space plasmas
X-Ray Constraints on Wandering Black Holes in Stripped Galaxy Nuclei in the Halo of NGC 5128. A subset of galaxies have dense nuclei, and when these galaxies are accreted and tidally stripped, the nuclei can masquerade as globular clusters in the halos of large galaxies. If these nuclei contain massive central black holes, some may accrete gas and become observable as active galactic nuclei. Previous studies have found that candidate stripped nuclei rarely host luminous X-ray sources, but these studies were typically restricted to both the most massive candidate nuclei and the most luminous X-ray sources. Here we use new and archival Chandra and XMM-Newton data to search for X-ray emission in a near-complete sample of massive globular clusters and candidate stripped nuclei in the nearest accessible elliptical galaxy, NGC 5128. This sample has the unique advantage that the candidate stripped nuclei are identified dynamically via elevated mass-to-light ratios (M/LV). Our central result is that 5/22 ( %) of the candidate stripped nuclei have X-ray sources down to a typical limit of LX ∼ 5 × 1036 erg s‑1, a fraction lower than or comparable to that among massive clusters with normal M/LV (16/41;  %). Hence we confirm and extend the result that nearly all X-ray sources in stripped nuclei are likely to be X-ray binaries rather than active galactic nuclei. If the candidate stripped nuclei have black holes of typical masses ∼2 × 105 M⊙ needed to explain their elevated M/LV, then they have typical Eddington ratios of ≲ 2 × 10‑6. This suggests that it will be challenging to conduct an accretion census of wandering black holes around even nearby galaxies.

Keywords: X-ray astronomy, Supermassive black holes, X-ray active galactic nuclei, Galaxy nuclei
Kinetic-scale Mirror Mode Storm Embedded in a Flux Rope in the Solar Wind. Mirror modes are ubiquitous in the space plasma environment. Mirror mode storms are successive trains of mirror modes, lasting for a long time. Previous studies generally focused on large-scale mirror mode storms. However, studies concerning kinetic-scale mirror mode storms are still lacking. In this work, we report a kinetic-scale mirror mode storm embedded in a magnetic flux rope in the near-Earth solar wind for the first time. As the mirror mode instability develops from unstable to marginally stable, the structures of the mirror mode that make up the mirror mode storm present a variation from small-amplitude dense peaks to large-amplitude sparse holes. With joint observations from the Magnetospheric Multiscale mission, ACE, and Wind, it is found that this mirror mode storm has been excited before reaching the near-Earth region. This kinetic-scale mirror mode storm might be caused by compression between slow and fast plasma flows inside the flux rope. Our observations provide a possible source and mechanism for the generation of kinetic-scale mirror mode storms.

Keywords: Space plasmas, Solar wind, Plasma astrophysics, Plasma physics
The Progenitor Systems of Classical Novae in M31. We present the first characterization of the statistical relationship between a large sample of novae in M31 and their progenitor stellar populations in the form of a delay time distribution. To this end, we leverage the spatially resolved stellar age distribution of the M31 disk derived from deep Hubble Space Telescope photometry by the Panchromatic Hubble Andromeda Treasury survey and a large catalog of novae in M31. Our delay time distribution has two statistically significant detections: one population of nova progenitors with ages between 2 and 3.2 Gyr and an unnormalized rate of (  events M⊙−1, and another of ages between 7.9 Gyr and the age of the Universe with (  events M⊙−1 (uncertainties are statistical and systematic, respectively). Together with the upper limits we derive at other time bins, these detections are consistent with either a constant production efficiency or a higher production efficiency of novae at earlier delay times.

Keywords: Star formation, Stellar evolution, Time domain astronomy, Classical novae
ChemicalUniverseMachine. I. Uncovering the Cosmic Evolution of Metals in the Galaxy–Interstellar Medium–Circumgalactic Medium Ecosystem. We present an empirical chemical evolution model that explains the distribution of metals in the interstellar medium (ISM) and the circumgalactic medium (CGM) of galaxies based on the UNIVERSEMACHINE and NEUTRALUNIVERSEMACHINE models in the framework of ΛCDM structure formation. We parameterize the fractions of outflowing metals returned and mixed into the multiphase ISM of the star-forming regions (fH2) and into the neutral gas regions (fH I); metal production, transfer, and dilution are caused by star formation, galaxy mergers, and gas inflow from the intergalactic medium, respectively, with rates determined by the (NEUTRAL)UNIVERSEMACHINE models. Using a Markov Chain Monte Carlo algorithm, we explore the posterior distributions of metal return and mixing consistent with observed mass–metallicity relations in H II regions (at 0 &lt; z &lt; 5), H I damped Lyα systems (at 1 &lt; z &lt; 4), and the CGM (at z = 0). We find that the fraction of metals present in the ISM, fH2 + fH I, increases with halo mass from ∼20% at 1010M⊙to ∼80% at 1013M⊙. These fractions increase mildly at higher redshifts, to ∼30% at 1010M⊙and ∼80% at 1013M⊙ at z = 5. Interestingly, there is no significant redshift evolution of fH2 + fH I at fixed circular velocity, suggesting that the metal distribution between the ISM and CGM is universally determined by the halo potential well depth. CGM metal enrichment is thus slow in high-z halos with deep potential wells. While fH2 monotonically increases with halo mass, fHI peaks at ∼1012‑1013M⊙, suggesting that reinfall may be inefficient in larger-mass halos.

Keywords: Galaxy evolution, Galaxy chemical evolution
A Multiwavelength Light-curve Analysis of the Classical Nova V392 Per: Optical Contribution from an Irradiated Accretion Disk during the Nova Wind Phase. The classical nova V392 Per 2018 is characterized by a very fast optical decline, a long binary orbital period of 3.23 days, detection of GeV gamma rays, and almost identical decay trends of the B, V, and IC light curves. The last feature is unique because most novae develop strong emission lines in the nebular phase and these lines contribute especially to the B and V bands and cause large differences between the BV and IC light curves. This unique feature can be understood if the optical flux is dominated by continuum until the late phase of the nova outburst. Such continuum radiation is emitted by a bright accretion disk irradiated by a hydrogen-burning white dwarf (WD) and a viscous heating disk with a high mass accretion rate after the hydrogen burning ends. We present a comprehensive nova outburst model that reproduces all of these light curves. We determine the WD mass to be MWD = 1.35–1.37 M⊙ and the distance modulus in the V band to be (m ‑ M)V = 14.6 ± 0.2; the distance is d = 3.45 ± 0.5 kpc for the reddening of E(B ‑ V) = 0.62.

Keywords: X-ray astronomy, High energy astrophysics, Fast novae, Shocks, Gamma-ray astronomy, Classical novae