Sazuna/UAT_keywords huggingface dataset:
Signatures of Active Galactic Nucleus Feedback Modes: A Green Bean Galaxy with 150 kpc Jet-induced Radio Emission. Jetted active galactic nuclei (AGN) hosting extended photoionized nebulae provide us with a unique view of the timescales associated with AGN activity. Here, we present a new green bean galaxy at z = 0.304458 ± 0.000007 with large-scale jet-induced radio emission. The spectral energy distributions of the radio components show steep spectral indices (α = ‑0.85 to ‑0.92 for the extended regions, and α = ‑1.02 for the faint radio core), and spectral age modeling of the extended radio emission indicates that the lobes are &gt;6 Myr old. It is unclear whether the jet is active, or is a remnant with an off-time of 2–3 Myr. Several detached clouds lie around the host galaxy up to 37.8 kpc away from the nucleus, and their ionization profile indicates a decline (∼2 dex) in the AGN ionizing photon production over the past ∼0.15 Myr. Furthermore, we measure a blueshift for one of the clouds that is spatially coincident with the path of the radio jet. The cloud is likely illuminated by the photoionizing AGN, and potentially underwent an interaction with the relativistic jet. Our multiwavelength analysis suggests that RGB1 was in a phase of jet production prior to the radiatively efficient accretion phase traced by the detached cloud emission. It is unclear whether RGB1 transitioned into a low-excitation radio galaxy or an inactive galaxy over the past ∼0.15 Myr, or whether the extended radio and optical emission trace distinct accretion phases that occurred in succession.

Keywords: AGN host galaxies, Active galaxies, Radio galaxies, Active galactic nuclei, Circumgalactic medium, Extragalactic astronomy
Characterizing the Average Interstellar Medium Conditions of Galaxies at z ∼ 5.6–9 with Ultraviolet and Optical Nebular Lines. Ultraviolet (UV; rest-frame ∼1200–2000 Å) spectra provide a wealth of diagnostics to characterize fundamental galaxy properties, such as their chemical enrichment, the nature of their stellar populations, and their amount of Lyman-continuum (LyC) radiation. In this work, we leverage publicly released JWST data to construct the rest-frame UV-to-optical composite spectrum of a sample of 63 galaxies at 5.6 &lt; z &lt; 9, spanning a wavelength range from 1500 to 5200 Å. Based on the composite spectrum, we derive an average dust attenuation  E(B‑V)gas=0.10‑0.11+0.10  from Hβ/Hγ, an electron density  ne=570‑290+510  cm‑3 from the [O II] doublet ratio, an electron temperature  Te=16700‑1500+1500  K from the [O III] λ4363/[O III] λ5007 ratio, and an ionization parameter  log(U)=‑2.15‑0.03+0.03  from the [O III]/[O II] ratio. Using a direct T  e  method, we calculate an oxygen abundance  12+log(O/H)=7.67±0.08  and a carbon-to-oxygen (C/O) abundance ratio  log(C/O)=‑0.86‑0.10+0.13 . This C/O ratio is smaller than compared to z = 0 and z = 2–4 star-forming galaxies, albeit with moderate significance. This indicates the reionization-era galaxies might be undergoing a rapid buildup of stellar mass with high specific star formation rates. A UV diagnostic based on the ratios of C III] λ λ1907, 1909/He II λ1640 versus O III] λ1666/He II λ1640 suggests that the star formation is the dominant source of ionization, similar to the local extreme dwarf galaxies and z ∼ 2–4 He II–detected galaxies. The [O III]/[O II] and C IV/C III] ratios of the composite spectrum are marginally larger than the criteria used to select galaxies as LyC leakers, suggesting that some of the galaxies in our sample are strong contributors to the reionizing radiation.

Keywords: Galaxy chemical evolution, Emission line galaxies, Reionization, Galaxy spectroscopy, High-redshift galaxies
A Hot Mess: The Rich and Complex Soft Emitting Regions Surrounding the Reflection Dominated Flaring Central Engine of Mrk 1239. Previous X-ray works on Mrk 1239 have revealed a complex narrow-line Seyfert 1 that exhibits substantial absorption and strong emission from both collisionally ionized and photoionized plasmas. Here, we report on deep-pointed observations with XMM-Newton and NuSTAR, along with Swift monitoring, to understand the 0.3─30 keV continuum emission and the central engine geometry. A strong X-ray flare, where the AGN brightens by a factor of 5 in ∼30 ks, is captured between 4 and 30 keV and can be attributed to a brightening of the primary continuum. However, the lack of any variability below ∼3 keV on long or short timescales requires complete absorption of the AGN continuum with a neutral medium of column density ∼1023.5 cm−2. The timing and spectral properties are consistent with a blurred reflection interpretation for the primary emission. The variability and presence of a Compton hump disfavors ionized partial covering. The neutral absorber, if outflowing, could be crashing into the surrounding medium and interstellar medium to produce the low-energy continuum and collisionally ionized emission. Scattered emission off the inner torus could produce the photoionized emission. The intricate scenario is demanded by the data and highlights the complexity of the environment that is normally invisible when overwhelmed by the AGN continuum. Objects like Mrk 1239 serve as important sources for unveiling the interface between the AGN and host galaxy environments.

Keywords: AGN host galaxies, Active galactic nuclei
Impact of Higher Harmonics of Gravitational Radiation on the Population Inference of Binary Black Holes. Templates modeling just the dominant mode of gravitational radiation are generally sufficient for the unbiased parameter inference of near-equal-mass compact binary mergers. However, neglecting the subdominant modes can bias the inference if the binary is significantly asymmetric, very massive, or has misaligned spins. In this work, we explore if neglecting these subdominant modes in the parameter estimation of nonspinning binary black hole mergers can bias the inference of their population-level properties such as mass and merger redshift distributions. Assuming the design sensitivity of the advanced LIGO-Virgo detector network, we find that neglecting subdominant modes will not cause a significant bias in the population inference, although including them will provide more precise estimates. This is primarily because asymmetric binaries are expected to be rarer in our detected sample, due to their intrinsic rareness and the observational selection effects. The increased precision in the measurement of the maximum black hole mass can help in better constraining the upper mass gap in the mass spectrum.

Keywords: Gravitational waves
A Multiwavelength Survey of Nearby M Dwarfs: Optical and Near-ultraviolet Flares and Activity with Contemporaneous TESS, Kepler/K2, Swift, and HST Observations. We present a comprehensive multiwavelength investigation into flares and activity in nearby M dwarf stars. We leverage the most extensive contemporaneous data set obtained through the Transiting Exoplanet Sky Survey, Kepler/K2, the Neil Gehrels Swift Observatory, and the Hubble Space Telescope, spanning the optical and near-ultraviolet (NUV) regimes. In total, we observed 213 NUV flares on 24 nearby M dwarfs, with ∼27% of them having detected optical counterparts, and found that all optical flares had NUV counterparts. We explore NUV/optical energy fractionation in M dwarf flares. Our findings reveal a slight decrease in the ratio of optical to NUV energies with increasing NUV energies, a trend in agreement with prior investigations on G–K stars' flares at higher energies. Our analysis yields an average NUV fraction of flaring time for M0–M3 dwarfs of 2.1%, while for M4–M6 dwarfs it is 5%. We present an empirical relationship between NUV and optical flare energies and compare to predictions from radiative hydrodynamic and blackbody models. We conducted a comparison of the flare frequency distribution (FFDs) of NUV and optical flares, revealing that the FFDs of both NUV and optical flares exhibit comparable slopes across all spectral subtypes. NUV flares on stars affect the atmospheric chemistry, the radiation environment, and the overall potential to sustain life on any exoplanets they host. We find that early and mid-M dwarfs (M0–M5) have the potential to generate NUV flares capable of initiating abiogenesis.

Keywords: M dwarf stars, Stellar flares, Near ultraviolet astronomy, Optical astronomy
Oblique Electrostatic Solitary and Supersolitary Waves in Earth's Magnetosheath. Nonlinear electrostatic solitary waves (ESWs) are routinely detected at various regions of Earth's magnetosphere using the Wideband Data plasma wave receivers mounted on board the Cluster satellite(s). This mission has facilitated the observation and analysis of ESW characteristics, such as amplitude and temporal duration within the magnetosheath, while concurrently determining the density and temperature profiles of energetic electrons. These electron parameters, in conjunction with data from ion experiments, have served as input for the ion-acoustic solitary wave model developed in this article, with the ambition to contribute to the understanding of ESW generation mechanisms. Assuming as the starting point a plasma system comprising inertial ion fluid and kappa-distributed electron populations of different temperatures (i.e., "cold" and "hot" electrons), a nonperturbative approach has been adopted to investigate the existence and properties of solitary waves. A thorough parametric investigation has scrutinized the existence conditions for such localized structures in terms of the plasma configuration parameters. An interesting aspect emerges from the analysis, namely, the possibility for the coexistence of positive and negative polarity structures associated with ion-acoustic modes, in fact, manifested as simultaneously occurring positive polarity supersolitary waves and negative polarity regular solitary waves. Furthermore, our study has investigated the combined effect of the magnetic field strength, electron density, and suprathermal electron statistics on wave dynamics. The outcomes of this research are in agreement with observed electrostatic wave phenomena in the magnetosheath region, thus underscoring the intrinsic relevance of electrostatic supersolitary structures in data obtained by Cluster and other satellite missions.

Keywords: Space plasmas, Plasma physics
Insights from the Gaussian Process Method for the Fast Radio Burst–associated X-Ray Burst of SGR 1935+2154. The Gaussian process method is employed to analyze the light curves of bursts detected by Insight-HXMT, Neutron Star Interior Composition Explorer (NICER), and Gravitational Wave High-energy Electromagnetic Counterpart All-sky Monitor from SGR 1935+2154 between 2020 and 2022. It is found that a stochastically driven damped simple harmonic oscillator (SHO) is necessary to capture the characteristics of the X-ray bursts (XRBs). A variability timescale of the XRBs, corresponding to the broken frequencies in the SHO power spectral densities (PSDs), is extracted. In particular, a high broken frequency of 35 Hz where the index of the SHO PSD changes from ‑4 to ‑2 is constrained by the HXMT-HE burst associated with fast radio burst (FRB) 200428. It is suggested that the corresponding timescale of 0.03 s could be the retarding timescale of the system driven by some energy release, and the production of the HE photon should be quasi-simultaneous with the response. The other special event is a NICER burst with a retarding timescale of 1/(39 Hz) ≈ 0.02 s. In the normal XRBs, no retarding timescale is constrained; a long relax/equilibrium timescale (corresponding to a broken frequency of 1–10 Hz, where the index of the SHO PSD changes from ‑4/‑2 to 0 in the SHO PSD) is obtained. The results indicate that the FRB-associated HXMT-HE XRB could be produced immediately when the system is responding to the energy disturbance, far before the equilibrium state.

Keywords: X-ray astronomy, Magnetars
Extreme-ultraviolet Polarimetric Diagnostics of the Solar Corona: The Hanle Effect of Ne VIII 770 Å. Magnetic fields are the primary driver of the plasma thermodynamics in the upper solar atmosphere, especially in the corona. However, magnetic field measurements in the solar corona are sporadic, thereby limiting us from the complete understanding of physical processes occurring in the coronal plasma. In this paper, we explore the diagnostic potential of a coronal emission line in the extreme-ultraviolet, i.e., Ne VIII 770 Å, to probe the coronal magnetic fields. We utilize 3D "Magnetohydrodynamic Algorithm outside a Sphere" models as input to the FORWARD code to model polarization in the Ne VIII line produced as a result of resonance scattering, and we interpret its modification due to collisions and the magnetic fields through the Hanle effect. The polarization maps are synthesized both on the disk and off the limb. The variation of this polarization signal through the different phases of Solar Cycle 24 and the beginning phase of Solar Cycle 25 is studied in order to understand the magnetic diagnostic properties of this line owing to different physical conditions in the solar atmosphere. The detectability of the linear polarization signatures of the Hanle effect significantly improves with increasing solar activity, consistent with the increase in the magnetic field strength and the intensity of the mean solar brightness at these wavelengths. We finally discuss the signal-to-noise ratio requirements by considering realistic instrument designs.

Keywords: Magnetohydrodynamics, Polarimetry, Solar corona, Solar extreme ultraviolet emission
Low-angular-momentum General Relativistic Magnetohydrodynamic Accretion Flows around Rotating Black Holes with Shocks. We investigate the global structure of the general relativistic magnetohydrodynamic (GRMHD) accretion flows around Kerr black holes containing shock waves, where the disk is threaded by radial and toroidal magnetic fields. We self-consistently solve the GRMHD equations that govern the flow motion inside the disk and for the first time, to our knowledge, we obtain the shock-induced global GRMHD accretion solutions around weakly as well as rapidly rotating black holes for a set of fundamental flow parameters, such as energy ( E ), angular momentum ( L ), radial magnetic flux (Φ), and isorotation parameter (F). We show that shock properties—namely, the shock radius (r sh), compression ratio (R), and shock strength (Ψ)—strongly depend on  E ,  L , Φ, and F. We observe that the shock in the GRMHD flow continues to exist for a wide range of the flow parameters, which allows us to identify the effective domain of the parameter space in the  L–E  plane where shock solutions are feasible. Moreover, we examine the modification of the shock parameter space and find that it shifts towards the lower-angular-momentum values with increasing Φ and black hole spin (a k). Finally, we compute the critical radial magnetic flux (Φcri) that admits shocks in GRMHD flows and ascertain that Φcri is higher (lower) for a black hole of spin a k = 0.99 (0.0) and vice versa.

Keywords: Accretion, Black hole physics, Magnetohydrodynamics, Shocks, Magnetic fields
Searching for Rapid Pulsations in Solar Flare X-Ray Data. Most studies of quasiperiodic pulsations (QPPs) in solar flares have identified characteristic periods in the 5–300 s range. Due to observational limitations, there have been few attempts to probe the &lt;5 s period regime and understand the prevalence of such short-period QPPs. However, the Fermi Gamma-ray Burst Monitor (GBM) has observed approximately 1500 solar flares to date in high-cadence 16 Hz burst mode, providing us with an opportunity to study short-period QPPs at X-ray energies. We systematically analyze every solar flare observed by Fermi/GBM in burst mode, estimating the prevalence of QPPs in multiple X-ray energy bands. To better understand these results, we complement this with an analysis of synthetic solar flare lightcurves, both with and without oscillatory signals present. Using these synthetic lightcurves, we can understand the likely false-alarm and true-positive rates in the real solar GBM data. We do not find strong evidence for widespread short-period QPPs, indicating either a low base occurrence rate of such signatures or that their typical signal-to-noise ratios must be low—less than 1—in Fermi/GBM data. Finally, we present a selection of the most interesting potential QPP events that were identified in the GBM solar X-ray data.

Keywords: Solar oscillations, Solar flares, Solar x-ray flares
Simultaneous Spectropolarimetric Observations in the Hα and Ca II 8662 Å Lines of an Active Region. We present spectropolarimetric observations of an active region recorded simultaneously in the Hα and the Ca II 8662 Å lines. The sunspot exhibits multiple structures, including a light bridge and a region where the Ca II 8662 Å line core is in emission. Correspondingly, the Hα line core image displays brightening in the emission region, with the spectral profiles showing elevated line cores. The stratification of the line-of-sight magnetic field is inferred through nonlocal thermodynamic equilibrium multiline inversions of the Ca II 8662 Å line and the weak field approximation (WFA) over the Hα line. The field strength inferred from the Hα line core is consistently smaller than that inferred from inversions at  logτ500  = ‑4.5. However, the study finds no correlation between the WFA over the core of the Hα line and that inferred from inversions at  logτ500  = ‑4.5. In regions exhibiting emission features, the morphology of the magnetic field at  logτ500  = ‑4.5 resembles that at  logτ500  = ‑1, with slightly higher or comparable field strengths. The magnetic field morphology inferred from the core of the Hα line is also similar to that inferred from the full spectral range of the Hα line in the emission region. The field strength inferred in the light bridge at  logτ500  = ‑1 is smaller than the surrounding umbral regions and comparable at  logτ500  = ‑4.5. Similarly, the field strength inferred in the light bridge from the WFA over the Hα line appears lower compared to the surrounding umbral regions.

Keywords: Solar magnetic fields, Solar chromosphere, Solar photosphere
Orbits and Dynamical Masses for Six Binary Systems in the Hyades Cluster. We report long-baseline interferometric observations with the CHARA Array that resolve six previously known double-lined spectroscopic binary systems in the Hyades cluster, with orbital periods ranging from 3 to 358 days: HD 27483, HD 283882, HD 26874, HD 27149, HD 30676, and HD 28545. We combine those observations with new and existing radial-velocity measurements, to infer the dynamical masses for the components as well as the orbital parallaxes. For most stars, the masses are determined to be better than 1%. Our work significantly increases the number of systems with mass determinations in the cluster. We find that, while current models of stellar evolution for the age and metallicity of the Hyades are able to reproduce the overall shape of the empirical mass–luminosity relation, they overestimate the V-band fluxes by about 0.1 mag between 0.5 and 1.4 M ⊙. The disagreement is smaller in H, and near zero in K, and depends somewhat on the model. We also make use of the TESS light curves to estimate rotation periods for our targets, and detect numerous flares in one of them (HD 283882), estimating an average flaring rate of 0.44 events per day.

Keywords: Binary stars, Interferometric binary stars, Spectroscopic binary stars, Stellar masses, Radial velocity
FEAST: Feedback in Emerging extragAlactic Star ClusTers: JWST Spots Polycyclic Aromatic Hydrocarbon Destruction in NGC 628 during the Emerging Phase of Star Formation. We investigate the emergence phase of young star clusters in the nearby spiral galaxy NGC 628. We use JWST NIRCam and MIRI observations to create spatially resolved maps of the Paα 1.87 μm and Brα 4.05 μm hydrogen recombination lines, as well as 3.3 and 7.7 μm emission from polycyclic aromatic hydrocarbons (PAHs). We extract 953 compact H II regions and analyze the PAH emission and morphology at ∼10 pc scales in the associated photodissociation regions. While H II regions remain compact, radial profiles help us to define three PAH morphological classes: compact (∼42%), extended (∼34%), and open (∼24%). The majority of compact and extended PAH morphologies are associated with very young star clusters (&lt;5 Myr), while open PAH morphologies are mainly associated with star clusters older than 3 Myr. We observe a general decrease in the 3.3 and 7.7 μm PAH band emission as a function of cluster age, while their ratio remains constant with age out to 10 Myr and morphological class. The recovered PAH3.3μm/PAH7.7μm ratio is lower than values reported in the literature for reference models that consider neutral and ionized PAH populations and analyses conducted at galactic physical scales. The 3.3 and 7.7 μm bands are typically associated with neutral and ionized PAHs, respectively. While we expected neutral PAHs to be suppressed in proximity to an ionizing source, the constant PAH3.3μm/PAH7.7μm ratio would indicate that both families of molecules disrupt at similar rates in proximity to H II regions.

Keywords: Polycyclic aromatic hydrocarbons, Star forming regions, Photodissociation regions, Interstellar medium, H II regions
Lessons from Hubble and Spitzer: 1D Self-consistent Model Grids for 19 Hot Jupiter Emission Spectra. We present a population-level analysis of the dayside thermal emission spectra of 19 planets observed with Hubble WFC3 and Spitzer IRAC 3.6 and 4.5 μm, spanning equilibrium temperatures 1200–2700 K and 0.7–10.5 Jupiter masses. We use grids of planet-specific 1D, cloud-free, radiative–convective–thermochemical equilibrium models (1D-RCTE) combined with a Bayesian inference framework to estimate atmospheric metallicity, the carbon-to-oxygen ratio, and day-to-night heat redistribution. In general, we find that the secondary eclipse data cannot reject the physics encapsulated within the 1D-RCTE assumption parameterized with these three variables. We find a large degree of scatter in atmospheric metallicities, with no apparent trend, and carbon-to-oxygen ratios that are mainly consistent with solar or subsolar values but do not exhibit population agreement. Together, these indicate either (1) formation pathways vary over the hot and ultra-hot Jupiter population and/or (2) more accurate composition measurements are needed to identify trends. We also find a broad scatter in derived dayside temperatures that do not demonstrate a trend with equilibrium temperature. Like with composition estimates, this suggests either significant variability in climate drivers over the population and/or more precise dayside temperature measurements are needed to identify a trend. We anticipate that 1D-RCTE models will continue to provide valuable insights into the nature of exoplanet atmospheres in the era of JWST.

Keywords: Exoplanet atmospheric composition , Bayesian statistics, Exoplanets, Extrasolar gaseous giant planets, Exoplanet atmospheres
Strong Bow Shocks: Turbulence and an Exact Self-similar Asymptotic. We show that strong bow shocks are turbulent and nonuniversal near the head but asymptote to a universal, steady, self-similar, and analytically solvable flow in the downstream. The turbulence is essentially 3D and has been confirmed by a 3D simulation. The asymptotic behavior is confirmed with high-resolution 2D and 3D simulations of a cold uniform wind encountering both a solid spherical obstacle and stellar wind. This solution is relevant in the context of (i) probing the kinematic properties of observed high-velocity compact bodies—e.g., runaway stars and/or supernova ejecta blobs—flying through the interstellar medium; and (ii) constraining stellar bow shock luminosities invoked by some quasiperiodic eruption models.

Keywords: Stellar bow shocks, Perturbation methods, Astrophysical fluid dynamics, Interstellar medium