Sazuna/UAT_keywords huggingface dataset:
EMRI + TDE = QPE: Periodic X-Ray Flares from Star-Disk Collisions in Galactic Nuclei. Roughly half of the quasiperiodic eruption (QPE) sources in galactic nuclei exhibit a remarkably regular alternating "long-short" pattern of recurrence times between consecutive flares. We show that a main-sequence star (brought into the nucleus as an extreme mass-ratio inspiral; EMRI) that passes twice per orbit through the accretion disk of the supermassive black hole (SMBH) on a mildly eccentric inclined orbit, each time shocking and ejecting optically thick gas clouds above and below the midplane, naturally reproduces observed properties of QPE flares. Inefficient photon production in the ejecta renders the QPE emission much harder than the blackbody temperature, enabling the flares to stick out from the softer quiescent disk spectrum. Destruction of the star via mass ablation limits the QPE lifetime to decades, precluding a long-lived AGN as the gaseous disk. By contrast, a tidal disruption event (TDE) naturally provides a transient gaseous disk on the requisite radial scale, with a rate exceeding the EMRI inward migration rate, suggesting that many TDEs should host a QPE. This picture is consistent with the X-ray TDE observed several years prior to the QPE appearance from GSN 069. Remarkably, a second TDE-like flare was observed from this event, starting immediately after detectable QPE activity ceased; this event could plausibly result from the (partial or complete) destruction of the QPE-generating star triggered by runaway mass loss, though other explanations cannot be excluded. Our model can also be applied to black hole-disk collisions, such as those invoked in the context of the candidate SMBH binary OJ 287.

Keywords: Supermassive black holes, Tidal disruption, Stellar dynamics, X-ray transient sources, Gravitational waves
Dust Coagulation in Oxygen-rich Circumstellar Outflows. We show that the inefficient growth of SiO molecules on (SiO) x  dust grains prolongs the period of maximum dust nucleation in circumstellar outflows resulting in a several orders-of-magnitude increase in the dust density near the star. This increase in dust density powers dust coagulation and results in the formation of large fractal aggregates that should be extremely efficient per unit mass in coupling to both the stellar radiation field and to the ambient gas.

Keywords: Circumstellar dust, Stellar winds
Jupiter Atmospheric Models and Outer Boundary Conditions for Giant Planet Evolutionary Calculations. We present updated atmospheric tables suitable for calculating the post-formation evolution and cooling of Jupiter and Jupiter-like exoplanets. These tables are generated using a 1D radiative transfer modeling code that incorporates the latest opacities and realistic prescriptions for stellar irradiation and ammonia clouds. To ensure the accuracy of our model parameters, we calibrate them against the measured temperature structure and geometric albedo spectrum of Jupiter, its effective temperature, and its inferred internal temperature. As a test case, we calculate the cooling history of Jupiter using an adiabatic and homogeneous interior and compare with extant models now used to evolve Jupiter and the giant planets. We find that our model reasonably matches Jupiter after evolving a hot-start initial condition to the present age of the solar system, with a discrepancy in brightness temperature/radius within 2%. Our algorithm allows us to customize for different cloud, irradiation, and metallicity parameters. This class of boundary conditions can be used to study the evolution of solar system giant planets and exoplanets with more complicated interior structures and nonadiabatic, inhomogeneous internal profiles.

Keywords: Planetary atmospheres, Solar system gas giant planets, Jupiter, Extrasolar gaseous giant planets, Exoplanet atmospheres
Nonparametric Inference of the Population of Compact Binaries from Gravitational-wave Observations Using Binned Gaussian Processes. The observation of gravitational waves from multiple compact binary coalescences by the LIGO-Virgo-KAGRA detector networks has enabled us to infer the underlying distribution of compact binaries across a wide range of masses, spins, and redshifts. In light of the new features found in the mass spectrum of binary black holes and the uncertainty regarding binary formation models, nonparametric population inference has become increasingly popular. In this work, we develop a data-driven clustering framework that can identify features in the component mass distribution of compact binaries simultaneously with those in the corresponding redshift distribution, from gravitational-wave data in the presence of significant measurement uncertainties, while making very few assumptions about the functional form of these distributions. Our generalized model is capable of inferring correlations among various population properties, such as the redshift evolution of the shape of the mass distribution itself, in contrast to most existing nonparametric inference schemes. We test our model on simulated data and demonstrate the accuracy with which it can reconstruct the underlying distributions of component masses and redshifts. We also reanalyze public LIGO-Virgo-KAGRA data from events in GWTC-3 using our model and compare our results with those from some alternative parametric and nonparametric population inference approaches. Finally, we investigate the potential presence of correlations between mass and redshift in the population of binary black holes in GWTC-3 (those observed by the LIGO-Virgo-KAGRA detector network in their first three observing runs), without making any assumptions about the specific nature of these correlations.

Keywords: Black holes, High energy astrophysics, Gravitational wave astronomy, Gravitational waves, Compact objects
Observation of Alfvén Ion Cyclotron Waves in ICME Magnetic Clouds at 1 au. Waves in plasma play an essential role in the energy transfer and plasma-heating processes. This article discusses the in situ observation of Alfvén ion cyclotron (AIC) waves and their characteristics within interplanetary coronal mass ejection (ICME) flux ropes. We analyzed 401 ICME flux ropes, observed by WIND spacecraft from 1995 to 2021 at 1 au. We found only five ICME flux ropes that show an explicit presence of AIC waves; two have normalized magnetic helicity σ  m  ≤ -0.5, and the remaining three show σ  m  ≥ 0.5 polarization. The angle between velocity and magnetic field (θ VB) for σ  m  ≤ -0.5 is &lt;40°, whereas for σ  m  ≥ 0.5, θ VB &gt; 140°. This result supports the existence of quasi-parallel and quasi-antiparallel left-handed polarized AIC waves within ICME flux ropes. We suggest that AIC waves are possibly triggered by (i) proton temperature anisotropy Tp ⊥/Tp ∥ &gt; 1 driven by cyclotron instability and (ii) low-frequency Alfvén waves through the magnetohydrodynamic turbulent cascade. This study shows evidence of fluid and kinetic scales coupling in the ICME flux rope.

Keywords: Magnetohydrodynamics
Evolution of the Mass-Metallicity Relation from Redshift z ≈ 8 to the Local Universe. A tight positive correlation between the stellar mass and the gas-phase metallicity of galaxies has been observed at low redshifts. The redshift evolution of this correlation can strongly constrain theories of galaxy evolution. The advent of JWST allows probing the mass-metallicity relation at redshifts far beyond what was previously accessible. Here we report the discovery of two emission line galaxies at redshifts 8.15 and 8.16 in JWST NIRCam imaging and NIRSpec spectroscopy of targets gravitationally lensed by the cluster RX J2129.4+0005. We measure their metallicities and stellar masses along with nine additional galaxies at 7.2 &lt; z spec &lt; 9.5 to report the first quantitative statistical inference of the mass-metallicity relation at z ≈ 8. We measure ~0.9 dex evolution in the normalization of the mass-metallicity relation from z ≈ 8 to the local universe; at a fixed stellar mass, galaxies are 8 times less metal enriched at z ≈ 8 compared to the present day. Our inferred normalization is in agreement with the predictions of FIRE simulations. Our inferred slope of the mass-metallicity relation is similar to or slightly shallower than that predicted by FIRE or observed at lower redshifts. We compare the z ≈ 8 galaxies to extremely low-metallicity analog candidates in the local universe, finding that they are generally distinct from extreme emission line galaxies or "green peas," but are similar in strong emission line ratios and metallicities to "blueberry galaxies." Despite this similarity, at a fixed stellar mass, the z ≈ 8 galaxies have systematically lower metallicities compared to blueberry galaxies.

Keywords: Metallicity, Galaxy chemical evolution, Chemical abundances, Galaxy evolution, High-redshift galaxies
The Galaxy Number Density Profile of Halos. More precise measurements of galaxy clustering will be provided by the next generation of galaxy surveys, such as DESI, WALLABY, and the Square Kilometre Array. To utilize this information to improve our understanding of the Universe, we need to accurately model the distribution of galaxies in their host dark matter halos. In this work, we present a new galaxy number density profile of halos, which makes predictions for the positions of galaxies in the host halo, different to the widely adopted Navarro-Frenk-White (NFW) profile, since galaxies tend to be found more in the outskirts of halos (nearer the virial radius) than an NFW profile. The parameterized galaxy number density profile model of halos is fit and tested using the DARK SAGE semi-analytic model of galaxy formation. We find that our galaxy number density profile model of halos can accurately reproduce the halo occupation distribution and galaxy two-point correlation function of the DARK SAGE simulation. We also derive the analytic expressions for the circular velocity and gravitational potential energy for this profile model. We use the SDSS Data Release 10 galaxy group catalog to validate this galaxy number density profile model of halos. Compared to the NFW profile, we find that our model more accurately predicts the positions of galaxies in their host halo and the galaxy two-point correlation function.

Keywords: Cosmology, Large-scale structure of the universe
New Covariant Density Functionals of Nuclear Matter for Compact Star Simulations. We generate three families of extended covariant density functionals of nuclear matter that have varying slope of symmetry energy and skewness at nuclear saturation density, but otherwise share the same basic parameters (symmetry energy, compressibility, saturation parameters, etc.) with the standard DDME2, DD2, and MPE functionals. Tables of the parameters of these new density functionals are given, which can be straightforwardly used in DDME2, DD2, and MPE parameterization-based codes. Furthermore, we provide tables of a large number of equations of state (81 for each family) that can be used in astrophysical simulations to assess the impact of variations of the not-well-known slope of symmetry energy and skewness of nuclear systems on the astrophysics of compact objects. We also provide tables of computed integral parameters (mass, radius, and tidal deformability) that can be used, e.g., for modeling gravitational waveforms. Finally, for the extended DDME2-based parameterization, we implement a first-order phase transition to quark matter to obtain a family of equations of state that accommodates a phase transition to quark matter. Analogous tables of the equations of state and integral parameters are provided for this case as well.

Keywords: Nuclear astrophysics, Neutron star cores, High energy astrophysics
Simultaneous Observation of the Inner and Outer Electron Diffusion Region in Reconnection with Large Guide Field. This paper presents a simultaneous observation of the inner and outer electron diffusion region (EDR) at the dayside magnetopause by the magnetospheric multiscale (MMS) spacecraft. The EDR was observed in magnetic reconnection with a large guide field. The inner EDR was characterized by positive ${\boldsymbol{J}}\cdot {{\boldsymbol{E}}}^{{\prime} }$ while the outer EDR is manifested by negative ${\boldsymbol{J}}\cdot {{\boldsymbol{E}}}^{{\prime} }$ and opposite out-of-plane electric field to that in the inner EDR. One pair of the spacecraft detected the inner EDR while the other pair encountered the outer EDR. Moreover, the two pairs were on the opposite side of the X-line as they observed the bidirectional accelerated electron jets. The fortuitous formation of MMS allows us to estimate the maximum length of the inner EDR as ~36 d  e  and the lower bound of the reconnection rate as 0.142 ± 0.041. These observations have far-reaching implications for understanding the electron physics in reconnection.

Keywords: Space plasmas, Solar magnetic reconnection, Plasma physics, Plasma astrophysics, Magnetic fields
Galactic Diffuse γ-Ray Emission from GeV to PeV Energies in Light of Up-to-date Cosmic-Ray Measurements. Diffuse γ-ray emission between 10 and 1000 TeV from the Galactic plane was recently measured by the Large High Altitude Air Shower Observatory (LHAASO). These observations will help tremendously in constraining the propagation and interaction of cosmic rays in the Milky Way. Additionally, new measurements of cosmic-ray spectra reach a very high precision of up to 100 TeV energies, revealing multiple spectral structures of various species. In this work, based on up-to-date measurements of local cosmic-ray spectra and a simplified propagation setup, we confront a model prediction of diffuse γ-ray emission with measurements of diffuse γ-rays. To better constrain the low-energy part of the model, we analyze the 14.6 yr of Fermi Large Area Telescope (Fermi-LAT) data to extract the Galactic diffuse emission between 1 and 500 GeV from the same sky regions of LHAASO, after subtracting the contribution from known sources and the isotropic diffuse γ-ray background. The joint Fermi-LAT and LHAASO spectra thus cover a very wide energy range from 1 GeV to 1 PeV with small gaps from 0.5 to 10 TeV. Compared with the prediction, we find that clear excesses between several GeV and ~60 TeV of the diffuse emission exist. Possible reasons to explain the excesses may include unresolved sources or more complicated propagation models. We illustrate that an exponential cutoff power-law component with an index of -2.40 and a cutoff energy of ~30 TeV is able to account for such excesses.

Keywords: Gamma-ray astronomy
Determining the Orbital Period and Wind Geometry in GRO J1655-40. During the course of its 2005 outburst, the black hole X-ray binary GRO J1655-40 launched an accretion disk wind associated with deep X-ray absorption lines and strong Compton scattering. Little is known about this apparently super-Eddington wind, but previous works have discovered optical/infrared (OIR) emission from the wind that varies on the orbital period-a possible clue to its origin and geometry. However, there is significant uncertainty in the orbital phases, and a more precise value of the orbital period is needed to accurately phase fold the wind emission. We present our analysis of the I-band photometry from observations taken with the Small and Medium Aperture Research Telescope System 1.3 m telescope between 2006 and 2016. We have implemented two methods-data-driven and model-based-to determine the orbital period, which we report as 2.62193 ± 0.00002 days from the data-driven method and 2.621928 ± 0.000004 days from the model-based method, a significant (25×) increase in precision over prior measurements. We discuss the possible existence of a period derivative, implications of a peculiar deep minimum in the outburst lightcurve of the system, and connections between OIR variability and the geometry of the super-Eddington wind.

Keywords: Accretion, Black hole physics, Stellar winds, X-ray binary stars
Toward a Physical Understanding of Galaxy-Halo Alignment. We investigate the alignment of galaxy and halo orientations using the TNG300-1 hydrodynamical simulation. Our analysis reveals that the distribution of the 2D misalignment angle θ 2D can be well described by a truncated shifted exponential distribution with only one free parameter across different redshifts and galaxy/halo properties. We demonstrate that the galaxy-ellipticity (GI) correlations of galaxies can be reproduced by perturbing halo orientations with the obtained θ 2D distribution, with only a small bias (&lt;3°) possibly arising from unaccounted for couplings between θ 2D and other factors. We find that both the 2D and 3D misalignment angles θ 2D and θ 3D decrease with ex situ stellar mass fraction F acc, halo mass M vir, and stellar mass M *, while increasing with the disk-to-total stellar mass fraction F disk and redshift. These dependences are in good agreement with our recent observational study based on BOSS galaxy samples. Our results suggest that F acc is a key factor in determining galaxy-halo alignment. Grouping galaxies by F acc nearly eliminates the dependence of θ 3D on M vir for all three principle axes, and also reduces the redshift dependence. For θ 2D, we find a more significant redshift dependence than for θ 3D even after controlling F acc, which may be attributed to the evolution of galaxy and halo shapes. Our findings present a valuable model for observational studies and enhance our understanding of galaxy-halo alignment.

Keywords: Weak gravitational lensing, Hydrodynamical simulations, Galaxy dark matter halos, Galaxy properties
Rest-frame Near-infrared Radial Light Profiles up to z = 3 from JWST/NIRCam: Wavelength Dependence of the Sérsic Index. We examine the wavelength dependence of radial light profiles based on Sérsic index n measurements of 1067 galaxies with M * ≥ 109.5 M ⊙ and in the redshift range 0.5 &lt; z &lt; 3. The sample and rest-frame optical light profiles are drawn from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) and 3D Hubble Space Telescope (HST); rest-frame near-infrared light profiles are inferred from images collected for the Cosmic Evolution Early Release Science (CEERS) program with the Near Infrared Camera (NIRCam) on board of the James Webb Space Telescope (JWST). n shows only a weak dependence on the wavelength, regardless of the redshift, galaxy mass, and type. On average, star-forming galaxies have n = 1-1.5 and quiescent galaxies have n = 3-4 in the rest-frame optical and near-infrared. The strong correlation at all wavelengths between n and star formation activity implies a physical connection between the radial stellar mass profile and star formation activity. The main caveat is that the current sample is too small to discern trends for the most massive galaxies (M * &gt; 1011 M ⊙).

Keywords: Galaxy quenching, Galaxy structure, Galaxy luminosities, Galaxy evolution
Effective Reaction Temperatures of Irreversible Dust Chemical Reactions in a Protoplanetary Disk. Dust particles in protoplanetary disks experience various chemical reactions under different physicochemical conditions through their accretion and diffusion, which results in the radial chemical gradient of dust. We performed three-dimensional Monte Carlo simulations to evaluate the dust trajectories and the progress of fictitious irreversible reactions, of which kinetics is expressed by the Johnson-Mehl-Avrami equation. The distribution of the highest temperature that each particle experiences before the degree of reaction exceeds a certain level shows the lognormal distribution, and its mode temperature was used as the effective reaction temperature. Semi-analytical prediction formulas of the effective reaction temperature and its dispersion were derived by comparing a reaction timescale with a diffusive transport timescale of dust as a function of the reaction parameters and the disk parameters. The formulas reproduce the numerical results of the effective reaction temperatures and their dispersions within 5.5% and 24%, respectively, in a wide temperature range (200-1400 K). We applied the formulas for the crystallization of amorphous silicate dust and its oxygen isotope exchange with the H2O vapor based on the experimentally determined kinetics. For submicron-sized amorphous forsterite dust, the predicted effective reaction temperature for the oxygen isotope exchange was lower than that of crystallization without overlap even considering their dispersions. This suggests that the amorphous silicate dust in the protosolar disk could exchange their oxygen isotopes efficiently with the 16O-poor H2O vapor, resulting in the distinct oxygen isotope compositions from the Sun.

Keywords: Dust composition, Cosmochemistry, Solar system, Astrochemistry, Solar system evolution, Protoplanetary disks
Evidence for Large-scale, Rapid Gas Inflows in z   2 Star-forming Disks. We report high-quality Hα/CO imaging spectroscopy of nine massive (log median stellar mass = 10.65 M ☉) disk galaxies on the star-forming main sequence (henceforth SFGs), near the peak of cosmic galaxy evolution (z ~ 1.1-2.5), taken with the ESO Very Large Telescope, IRAM-NOEMA, and Atacama Large Millimeter/submillimeter Array. We fit the major axis position-velocity cuts with beam-convolved, forward models with a bulge, a turbulent rotating disk, and a dark matter (DM) halo. We include priors for stellar and molecular gas masses, optical light effective radii and inclinations, and DM masses from our previous rotation curve analysis of these galaxies. We then subtract the inferred 2D model-galaxy velocity and velocity dispersion maps from those of the observed galaxies. We investigate whether the residual velocity and velocity dispersion maps show indications for radial flows. We also carry out kinemetry, a model-independent tool for detecting radial flows. We find that all nine galaxies exhibit significant nontangential flows. In six SFGs, the inflow velocities (v  r  ~ 30-90 km s-1, 10%-30% of the rotational component) are along the minor axis of these galaxies. In two cases the inflow appears to be off the minor axis. The magnitudes of the radial motions are in broad agreement with the expectations from analytic models of gravitationally unstable, gas-rich disks. Gravitational torques due to clump and bar formation, or spiral arms, drive gas rapidly inward and result in the formation of central disks and large bulges. If this interpretation is correct, our observations imply that gas is transported into the central regions on ~10 dynamical timescales.

Keywords: Galaxy evolution, Galaxy structure, High-redshift galaxies, Galaxy kinematics
Investigating the Magnetic Structure of Interplanetary Coronal Mass Ejections Using Simultaneous Multispacecraft In Situ Measurements. In situ measurements from spacecraft typically provide a time series at a single location through coronal mass ejections (CMEs), and they have been one of the main methods to investigate CMEs. The CME properties derived from these in situ measurements are affected by temporal changes that occur as the CME passes over the spacecraft, such as radial expansion and aging, as well as spatial variations within a CME. This study uses multispacecraft measurements of the same CME at close separations to investigate both the spatial variability (how different a CME profile is when probed by two spacecraft close to each other) and the so-called aging effect (the effect of the time evolution on in situ properties). We compile a database of 19 events from the past 4 decades measured by two spacecraft with a radial separation of &lt;0.2 au and an angular separation of &lt;10°. We find that the average magnetic field strength measured by the two spacecraft differs by 18% of the typical average value, which highlights nonnegligible spatial or temporal variations. For one particular event, measurements taken by the two spacecraft allow us to quantify and significantly reduce the aging effect to estimate the asymmetry of the magnetic field strength profile. This study reveals that single-spacecraft time series near 1 au can be strongly affected by aging and that correcting for self-similar expansion does not capture the whole aging effect.

Keywords: Solar coronal mass ejections, Heliosphere