Sazuna/UAT_keywords huggingface dataset:
Reinvestigating the Gamow Factor of Reactions on Light Nuclei. We present a modified Gamow factor by reinvestigating the conventional assumptions used in its derivation. The conventional Gamow factor, factorized from the total cross section, effectively describes the penetration probabilities (PPs) in low-energy nuclear reactions under the assumption of particle energies significantly lower than the Coulomb barrier. However, we find that the assumption is invalid for light nuclei, resulting in PPs that depend on the nuclear potential depth for such nuclei. By adopting a potential depth fitted to experimental fusion cross sections, we demonstrate that PPs for light nuclei (D+D, D+T, D+3He, p+D, p+6Li, and p+7Li) become higher than those predicted by the conventional form near the Coulomb barrier. This reduces the Gamow peak energy by a factor of 5.3 maximally compared to the conventional form. Furthermore, we show that the enhancement factor due to the Debye screening effects in the solar core can be reduced by approximately 5%-10% due to the modified PP. Our findings hold implications for evaluating the available energy region in low-energy reaction experiments based on the Gamow peak energy region and for understanding electron screening effects in typical astrophysical environments.

Keywords: Nuclear astrophysics, Nuclear physics, Nuclear reaction cross sections
KIC 9845907: A δ Scuti Star with the First Overtone as the Dominant Frequency and with Many Equidistant Structures in Its Spectrum. In this paper, we present an analysis of the pulsating behavior of Kepler target KIC 9845907. Using the data from Kepler, we detected 85 significant frequencies, including the first overtone f 1 = 17.597 day-1 as the dominant frequency, the non-radial independent frequency f 3 = 31.428 day-1 (ℓ = 1), as well as two modulation terms f  m1 = 0.065 day-1 and f  m2 = 1.693 day-1. We found fourteen pairs of triplet structures with f  m1 or f  m2, four pairs of which can further form quintuplet structures. We note these are the most intriguing features discovered in this study and they were recognized for the first time in δ Scuti stars. We discussed several possible explanations, i.e., beating, the Blazhko effect, combination mode hypothesis, nonlinear mode coupling, large separation, and stellar rotational splitting for these equidistant structures. Our asteroseismic models indicate this modulation with f  m1 might be related to the rotational splitting. The study of more δ Scuti stars with triplet and/or quintuplet structures using high-precision space photometry would be helpful to further explore its origin.

Keywords: Stellar oscillations, Delta Scuti variable stars
Detection of the Extended γ-Ray Emission around Supernova Remnant DA 530 with Fermi-LAT. We report the extended GeV γ-ray emission around the high Galactic latitude supernova remnant DA 530 with the PASS 8 data recorded by the Fermi Large Area Telescope. The γ-ray spectrum in the energy range of 100 MeV-1 TeV follows a power-law model with an index of 2.23. The γ-ray emission, which is much more extended than the radio shell of DA 530, and the spatial coincidence with the molecular cloud suggest that the γ-ray emission could be originated from the hadronic process, where the high-energy protons accelerated in and escaped from the shock of DA 530. With a steady-state injection model of protons, the γ-ray spectrum can be well fitted with the typical Galactic value for the diffusion coefficient and the low-energy content of the total escaped protons.

Keywords: Supernova remnants, Gamma-ray sources, Gamma-rays, Molecular clouds
Sm and Gd Isotopic Shifts in Eucrites and Implications for Their Cosmic-Ray Exposure History. The isotopic compositions of Sm and Gd in eight eucrites-five from a desert, Dar al Gani (DaG) 380, DaG 391, DaG 411, DaG 443, and DaG 480, and three from nondesert areas, Juvinas, Millibillillie, and Stannern-were determined to understand the cosmic-ray exposure (CRE) history for each meteorite from the isotopic shifts of 149Sm-150Sm and 157Gd-158Gd caused by the neutron capture reactions induced by cosmic-ray irradiation. Seven of the eight samples, excepting DaG 443, show readily detectable isotopic shifts of Sm and Gd corresponding to neutron fluences in the range of (0.28-2.38) × 1015 neutrons cm-2. The degrees of Sm isotopic shifts for six of these seven eucrites can be consistently explained by the CRE age histogram of eucrites obtained in previous studies. Exceptionally, DaG 480 shows larger isotopic shifts of Sm than those expected from the CRE age histogram, suggesting a multiple-irradiation history, including irradiation on the parent body. However, there is no clear difference in the CRE conditions between DaG 480 and other eucrites from the parameter ɛ Sm/ɛ Gd to identify the difference in the thermalization degree of neutrons in association with the CRE conditions.

Keywords: Galactic cosmic rays, Isotopic abundances, Asteroid surfaces
QPOs in Compact Sources as a Nonlinear Hydrodynamical Resonance: Determining Spin of Compact Objects. The origin of wide varieties of quasiperiodic oscillations (QPOs) observed in compact sources is still not well established. Its frequencies range from millihertz to kilohertz spanning all compact objects. Are different QPOs, with different frequencies, originating from different physics? We propose that the emergence of QPOs is the result of nonlinear resonance of fundamental modes present in accretion disks forced by external modes including that of the spin of the underlying compact object. Depending on the properties of accreting flow, e.g., its velocity and gradient, resonances (and any mode-locking) take place at different frequencies, exhibiting low- to high-frequency QPOs. We explicitly demonstrate the origin of higher-frequency QPOs for black holes and neutron stars by a unified model and outline how the same physics could be responsible for producing lower-frequency QPOs. The model also predicts the spin of black holes, and constrains the radius of neutron stars and the mass of both.

Keywords: Neutron stars, Black hole physics, Accretion, Hydrodynamics, Gravitation, Stellar oscillations
Dynamics of Threads Wrapping a Filament's Leg Prior to the Eruption on 2021 October 28. Although the magnetic field structures of solar filaments have been studied for several decades, the detailed evolution of the structure around a filament prior to its eruption is rarely observed. On 2021 October 28 in AR 12887, a major solar flare (X1.0 class) occurred at 15:35 UT. Based on the Solar Dynamics Observatory high-spatial-resolution observations, we find this flare is associated with the eruption of two filaments, namely F1 and F2. The two filaments are initially independent. The western leg (WLEG) of F1 approaches the northern leg of F2, due to the continuous movement and rotation of the magnetic field in which the WLEG roots in. We find first that there are some threads wrapping the WLEG. Brightening and bidirectionally plasmoid flows that originate from a brightening are detected in these threads, then the threads disappear, and the two filaments connect. NLFFF extrapolation reveals that there is a toroidal magnetic structure enveloping the WLEG and corresponding spatially to the threads. It is expected that a filament is enveloped by toroidal magnetic fields. According to the observations and extrapolation, we suggest that these threads represent the toroidal magnetic fields wrapping the WLEG. This paper provides new details about the dynamics of the toroidal magnetic fields. Magnetic reconnection takes place in the toroidal fields and thus destroys the fields, then F1 and F2 connect, and subsequently, the two filaments erupt and the flare occurs.

Keywords: Solar flares, Solar magnetic reconnection, Solar filaments, Solar filament eruptions, Solar activity
Three-dimensional Simulation of Thermodynamics on Confined Turbulence in a Large-scale CME-flare Current Sheet. Turbulence plays a key role in forming the complex geometry of the large-scale current sheet (CS) and fast energy release in a solar eruption. In this paper, we present full 3D high-resolution simulations for the process of a moderate coronal mass ejection (CME) and the thermodynamical evolution of the highly confined CS. Copious elongated blobs are generated owing to tearing and plasmoid instabilities, giving rise to a higher reconnection rate, and undergo the splitting, merging, and kinking processes in a more complex way in 3D. A detailed thermodynamical analysis shows that the CS is mainly heated by adiabatic and numerical viscous terms, and thermal conduction is the dominant factor that balances the energy inside the CS. Accordingly, the temperature of the CS reaches to a maximum of about 20 MK, and the range of temperatures is relatively narrow. From the face-on view in the synthetic Atmospheric Imaging Assembly 131 Å, the downflowing structures with similar morphology to supra-arcade downflows are mainly located between the post-flare loops and loop top, while moving blobs can extend spikes higher above the loop top. The downward-moving plasmoids can keep the twisted magnetic field configuration until the annihilation at the flare loop top, indicating that plasmoid reconnection dominates in the lower CS. Meanwhile, the upward-moving ones turn into turbulent structures before arriving at the bottom of the CME, implying that turbulent reconnection dominates in the upper CS. The spatial distributions of the turbulent energy and anisotropy are addressed, which show a significant variation in the spectra with height.

Keywords: Solar coronal mass ejections, Solar magnetic reconnection, Magnetohydrodynamical simulations
High-order Harmonics of a Kink Wave and a Narrow Quasiperiodic Fast-propagating Wave Train Excited Simultaneously in a Plasma Resonator. We present the observations of multimode kink waves and a narrow quasiperiodic fast-propagating (QFP) wave train in association with a jet on 2011 December 11. The jet impinged on a loop, which excited a propagating kink mode transitioning into a standing kink mode and also excited a QFP wave train away from the jet. Motion magnification is used to fit the higher harmonic standing wave oscillation profile with three periods at three different spatial locations. The periods have the ratio 6:3:2. The ratio of the fundamental mode to the second harmonic of the standing wave is about 1.95, suggesting that the magnetic field strength variation effect is strong enough to cancel out the density stratification. The differential emission measure is used to estimate the loop's plasma property at these three points, and it found the density and the temperature are roughly constant. The magnetic field strength, B = 51 ± 16 G, is derived by the coronal seismology using the fundamental kink mode. It is striking to find that the the ratio of the second harmonic to the third harmonic of the kink wave coincides with that of the periods of the QFP wave train, and the ratio of periods is about 1.5 in both cases. We propose that the excitation of the high-order harmonics and the QFP wave train could be the nonlinear response of the steep density-gradient plasma interacting with electromagnetic field in the southwest foot region. This region, like a resonator, might play an important role in energy reservoir capture and act as a frequency filter to generate propagating waves of particular frequencies.

Keywords: Solar coronal loops, Solar coronal waves
Investigating a Solar Wind Stream Interaction Region using Interplanetary Spacecraft Radio Signals: A Magnetohydrodynamic Simulation Study. Stream interaction regions (SIRs) are spiral heliospheric structures that arise at the interface between fast and preceding slow solar wind regions. SIR enhancements of density and magnetic field intensity, often with magnetic polarity inversion, are potentially geoeffective and therefore important in the analysis of space weather. We studied an MHD heliospheric simulation containing a well-defined SIR using a new instrument concept based on trans-heliospheric radio sensing: Faraday Effect Tracker of Coronal and Heliospheric structures (FETCH). FETCH uses line-of-sight radio propagation techniques to measure Faraday rotation and electron column density. Analysis of the simulated FETCH observations clearly demonstrated density and magnetic field enhancements, and magnetic polarity reversal, all of which were confirmed in Wind spacecraft measurements at 1 au. FETCH provided 4.5-5.7 days lead times for predicting the arrival of SIR features at Earth. The SIR radial speed was estimated to be 350-390 km s-1. These initial results hold promise that FETCH will be valuable in detecting and characterizing the inner heliosphere SIR properties well ahead of their presentation in the local geospace environment.

Keywords: Solar wind, Interplanetary physics, Heliosphere
Are JWST/NIRCam Color Gradients in the Lensed z = 2.3 Dusty Star-forming Galaxy El Anzuelo Due to Central Dust Attenuation or Inside-out Galaxy Growth?. Gradients in the mass-to-light ratio of distant galaxies impede our ability to characterize their size and compactness. The long-wavelength filters of JWST's NIRCam offer a significant step forward. For galaxies at Cosmic Noon (z ~ 2), this regime corresponds to the rest-frame near-infrared, which is less biased toward young stars and captures emission from the bulk of a galaxy's stellar population. We present an initial analysis of an extraordinary lensed dusty star-forming galaxy at z = 2.3 behind the El Gordo cluster (z = 0.87), named El Anzuelo ("The Fishhook") after its partial Einstein-ring morphology. The far-UV to near-IR spectral energy distribution suggests an intrinsic star formation rate of ${81}_{-2}^{+7}\,{M}_{\odot }\,{\mathrm{yr}}^{-1}$ and dust attenuation A  V  ≈ 1.6, in line with other DSFGs on the star-forming main sequence. We develop a parametric lens model to reconstruct the source-plane structure of dust imaged by the Atacama Large Millimeter/submillimeter Array, far-UV to optical light from Hubble, and near-IR imaging with 8 filters of JWST/NIRCam, as part of the Prime Extragalactic Areas for Reionization and Lensing Science program. The source-plane half-light radius is remarkably consistent from ~1 to 4.5 μm, despite a clear color gradient where the inferred galaxy center is redder than the outskirts. We interpret this to be the result of both a radially decreasing gradient in attenuation and substantial spatial offsets between UV- and IR-emitting components. A spatial decomposition of the SED reveals modestly suppressed star formation in the inner kiloparsec, which suggests that we are witnessing the early stages of inside-out quenching.

Keywords: Starburst galaxies, Strong gravitational lensing, James Webb Space Telescope
First Results from the JWST Early Release Science Program Q3D: Ionization Cone, Clumpy Star Formation, and Shocks in a z = 3 Extremely Red Quasar Host. Massive galaxies formed most actively at redshifts z = 1-3 during the period known as "cosmic noon." Here we present an emission-line study of the extremely red quasar SDSSJ165202.64+172852.3's host galaxy at z = 2.94, based on observations with the Near Infrared Spectrograph integral field unit on board JWST. We use standard emission-line diagnostic ratios to map the sources of gas ionization across the host and a swarm of companion galaxies. The quasar dominates the photoionization, but we also discover shock-excited regions orthogonal to the ionization cone and the quasar-driven outflow. These shocks could be merger-induced or-more likely, given the presence of a powerful galactic-scale quasar outflow-these are signatures of wide-angle outflows that can reach parts of the galaxy that are not directly illuminated by the quasar. Finally, the kinematically narrow emission associated with the host galaxy presents as a collection of 1 kpc-scale clumps forming stars at a rate of at least 200 M ⊙ yr-1. The interstellar medium within these clumps shows high electron densities, reaching up to 3000 cm-3, with metallicities ranging from half to a third solar with a positive metallicity gradient, and V-band extinctions up to 3 mag. The star formation conditions are far more extreme in these regions than in local star-forming galaxies but consistent with those of massive galaxies at cosmic noon. The JWST observations simultaneously reveal an archetypal rapidly forming massive galaxy undergoing a merger, a clumpy starburst, an episode of obscured near-Eddington quasar activity, and an extremely powerful quasar outflow.

Keywords: AGN host galaxies, Photoionization, Quasars, Galaxy mergers, Galaxy evolution
GRB-SN Association within the Binary-driven Hypernova Model. Observations of supernovae (SNe) Ic occurring after the prompt emission of long gamma-ray bursts (GRBs) are addressed within the binary-driven hypernova (BdHN) model where GRBs originate from a binary composed of a ~10M ⊙ carbon-oxygen (CO) star and a neutron star (NS). The CO core collapse gives the trigger, leading to a hypernova with a fast-spinning newborn NS (νNS) at its center. The evolution depends strongly on the binary period, P bin. For P bin ~ 5 min, BdHNe I occur with energies 1052-1054 erg. The accretion of SN ejecta onto the NS leads to its collapse, forming a black hole (BH) originating the MeV/GeV radiation. For P bin ~ 10 min, BdHNe II occur with energies 1050-1052 erg and for P bin ~ hours, BdHNe III occur with energies below 1050 erg. In BdHNe II and III, no BH is formed. The 1-1000 ms νNS originates, in all BdHNe, the X-ray-optical-radio afterglows by synchrotron emission. The hypernova follows an independent evolution, becoming an SN Ic, powered by nickel decay, observable after the GRB prompt emission. We report 24 SNe Ic associated with BdHNe. Their optical peak luminosity and time of occurrence are similar and independent of the associated GRBs. From previously identified 380 BdHN I comprising redshifts up to z = 8.2, we analyze four examples with their associated hypernovae. By multiwavelength extragalactic observations, we identify seven new episodes, theoretically explained, fortunately not yet detected in Galactic sources, opening new research areas. Refinement of population synthesis simulations is needed to map the progenitors of such short-lived binary systems inside our galaxy.

Keywords: Gamma-ray bursts
The JWST Hubble Sequence: The Rest-frame Optical Evolution of Galaxy Structure at 1.5 &lt; z &lt; 6.5. We present results on the morphological and structural evolution of a total of 3956 galaxies observed with JWST at 1.5 &lt; z &lt; 6.5 in the JWST CEERS observations that overlap with the CANDELS EGS field. This is the biggest visually classified sample observed with JWST yet, ~20 times larger than previous studies, and allows us to examine in detail how galaxy structure has changed over this critical epoch. All sources were classified by six individual classifiers using a simple classification scheme aimed at producing disk/spheroid/peculiar classifications, whereby we determine how the relative number of these morphologies has evolved since the Universe's first billion years. Additionally, we explore structural and quantitative morphology measurements using MORFOMETRYKA, and show that galaxies with M * &gt; 109 M ⊙ at z &gt; 3 are not dominated by irregular and peculiar structures, either visually or quantitatively, as previously thought. We find a strong dominance of morphologically selected disk galaxies up to z = 6 in this mass range. We also find that the stellar mass and star formation rate densities are dominated by disk galaxies up to z ~ 6, demonstrating that most stars in the Universe were likely formed in a disk galaxy. We compare our results to theory to show that the fraction of types we find is predicted by cosmological simulations, and that the Hubble Sequence was already in place as early as one billion years after the Big Bang. Additionally, we make our visual classifications public for the community.

Keywords: Galaxy classification systems
Secondary Proton Beam Instability in a Turbulent Solar Wind at 50 R <SUB>⊙</SUB>. We investigate a secondary proton beam instability coexisting with the ambient solar wind turbulence at 50 R ☉. Three-dimensional hybrid numerical simulations (particle ions and a quasi-neutralizing electron fluid) are carried out with the plasma parameters in the observed range. In the turbulent background, the particle distribution function, in particular the slope of the "bump-on-tail" responsible for the instability, is time-dependent and inhomogeneous. The presence of the turbulence substantially reduces the growth rate and saturation level of the instability. We derive magnetic power spectra from the observational data and perform a statistical analysis to evaluate the average turbulence intensity at 50 R ☉. This information is used to link the observed frequency spectrum to the wavenumber spectrum in the simulations. We verify that Taylor's frozen-in hypothesis is valid for this purpose to a sufficient extent. To reproduce the typical magnetic power spectrum of the instability observed concurrently with the background turbulence, an artificial spacecraft probe is run through the simulation box. The thermal-ion instabilities are often seen as power elevations in the kinetic range of scales above an extrapolation of the turbulence spectrum from larger scales. We show that the elevated power in the simulations is much higher than the background level. Therefore, the turbulence at the average intensity does not obscure the secondary proton beam instability, as opposed to the solar wind at 1 au, in which the ambient turbulence typically obscures thermal-ion instabilities.

Keywords: Interplanetary turbulence, Space plasmas, Solar wind
Back to Business: SLX 1746-331 after 13 Years of Silence. The black hole candidate system SLX 1746-331 was back to business in 2023, after a long silence of roughly 13 years. An outburst was observed thoroughly by Insight-HXMT and NICER. The outburst is characterized by spectral dominance of the soft state, where the joint Insight-HXMT and NICER spectral analysis shows the temperature dependence of the disk flux follows ${T}_{\mathrm{in}}^{3.98}$ , and thus suggests that the inner disk reaches its innermost stable circular orbit during almost the entire outburst. By assuming 0.3 L Edd for the peak flux and an inclination angle of zero degrees, the lower limit of the compact object hosted in this system is estimated as 3.28 ± 2.14 M ⊙. We also look into the relation between the disk temperature and disk flux for a sample of black hole systems, and by taking the disk temperature derived in the outburst of SLX 1746-331, such a relation results in a mass estimation of 5.2 ± 4.5 M ⊙. Finally, the spin of the compact object is constrained to be larger than 0.8 with the spectral model KERRBB.

Keywords: X-ray binary stars