Sazuna/UAT_keywords huggingface dataset:
Backtracking Bipolar Magnetic Regions to Their Emergence: Two Groups and Their Implication in the Tilt Measurements. Bipolar magnetic regions (BMRs) that appear on the solar photosphere are surface manifestations of the Sun's internal magnetic field. With modern observations and continuous data streams, the study of BMRs has moved from manual sunspot catalogs to automated detection and tracking methods. In this work, we present an additional module to the existing BMR tracking algorithm, the Automatic Tracking Algorithm for Bipolar Magnetic Regions (AutoTAB), which focuses on identifying emerging signatures of BMRs. Specifically, for regions newly detected on the solar disk, this module backtracks the BMRs to their point of emergence. From a total of about 12,000 BMRs identified by AutoTAB, we successfully backtracked 3080 cases. Within this backtracked sample, we find two distinct populations. One group shows the expected behavior of emerging regions, in which the magnetic flux increases significantly during the emerging phase. The other group consists of BMRs whose flux, however, does not exhibit substantial growth during their evolution, the instances where our algorithm fails to capture the initial emergence of the BMRs. We classify these as "discarded" BMRs and examine their statistical properties separately. Our analysis shows that these discarded BMRs do not display any preferred tilt angle distribution and do not show systematic latitudinal tilt dependence, in contrast to the trends typically associated with emerging BMRs. This indicates that including such regions in statistical studies of BMR properties can distort or mask the underlying physical characteristics. We therefore emphasise the importance of excluding the discarded population from the whole dataset when analysing the statistical behavior of BMRs.

Keywords: Solar cycle, Solar active region magnetic fields, Sunspot groups, Solar interior, Sunspots, Bipolar sunspot groups, Solar surface, Solar physics, Solar magnetic fields, Solar activity, Sunspot cycle
Warm and Cold Molecular Gas in the Cluster Center of MACS 1931−26 with JWST and ALMA. We perform one of the first spatially resolved studies of warm (&gt;100 K) and cold (10─100 K) molecular gas in the circumgalactic medium (CGM), focusing on the brightest cluster galaxy (BCG) of a cool-core galaxy cluster, MACS 1931−26, at z = 0.35. This galaxy has a massive H2 reservoir and a radio-loud active galactic nucleus and is undergoing a starburst event. We present new JWST observations of this system, revealing warm H2 gas that is cospatial with the cold molecular gas traced by CO, extending over 30 kpc around the BCG in a tail-like structure reaching into the CGM of this galaxy. Analysis of the mid-infrared pure H2 rotational lines H2 S(1), H2 S(5), and H2 S(9) indicate warm gas temperatures of 515.6 ± 0.8 and 535.2 ± 1.9 K in the BCG and tail regions, respectively. We compare the cold gas traced by the CO(3─2) observed with the Atacama Large Millimeter/submillimeter Array to the warm gas traced by JWST. The warm-to-cold molecular gas fraction is comparable in the BCG (1.4% ± 0.2%) and the CGM tail (1.9% ± 0.3%). Our analysis suggests that the dissipation of the kinetic energy of the H2-emitting gas is sufficient to lead to the formation of the CO gas. This observation provides new insights into the molecular gas distribution and its potential role in the interplay between the central galaxy and its circumgalactic environment.

Keywords: AGN host galaxies, Active galaxies, Star formation, Galaxy evolution, Circumgalactic medium
The Source of Energetic Storm Particles for the 2023 March 13 Event Observed by Parker Solar Probe. On 2023 March 13, Parker Solar Probe was located about 0.23 au from the Sun when it was crossed by a very fast interplanetary shock. The intensities of ∼0.08─10 MeV energetic protons were markedly enhanced at the shock crossing. At energies from ∼0.1 to 1 MeV, the intensity at the shock was 3─4 orders of magnitude larger than it was ∼4 hr prior. In this study, we investigate the possible source of particles that led to this enhancement. Pre-existing high-energy particles that were present during the few-hour period prior to the shock could possibly serve as a source, assuming they are accelerated to even higher energies by the shock. We apply a "seeds test"—which determines the expected enhancement at the shock—to test this. We find that none of the pre-existing particle populations identified can account for the observed enhancement at the shock. The solar wind itself provides a very abundant source. To test whether shock-heated thermal solar wind could account for the source, we perform a series of self-consistent hybrid plasma simulations of this event and make direct comparisons with the observed particle spectra and magnetic field. We conclude that shock-heated solar wind protons are the source of energetic particles in this event. The direct comparisons of our simulations and observations also suggest that the shock was moving about 1350 km s−1 and had an Alfvén Mach number of about 4, both of which are considerably lower than previously estimated.

Keywords: Interplanetary shocks, Solar energetic particles, Plasma astrophysics, Interplanetary particle acceleration, Solar coronal mass ejections
Estimating JUNO's Sensitivity to Solar Neutrino-to-antineutrino Conversion and Neutrino Magnetic Moments. We investigated JUNO's sensitivity to a possible conversion of solar neutrinos into antineutrinos via the spin-flavor precession mechanism, and assessed the implications for constraining the neutrino-magnetic moment. Using a sensitivity-based framework appropriate for counting experiments with no prior observations, we derive 90% confidence level ensemble-average sensitivities on the solar antineutrino flux for 1.8─16.8 and 8.0─16.8 MeV. For the entire energy window, the results do not improve the restrictions of other experiments; the relevance occurs in the highest-energy window. In this window, we report a flux of  ϕlim≤4.01×101cm−2s−1  and a probability of  Pνe→ν̄e≤2.07×10−5 , the latter normalized to the 8B flux above threshold, ΦSSM(E &gt; 8 MeV). Assuming transverse solar magnetic fields of B⊥ = 50 and 100 kG, the corresponding magnetic-moment sensitivities are μν ≤ 7.27 × 10−11 μB and 3.64 × 10−11 μB in the high-energy window. These results highlight that JUNO has the potential to achieve sensitivities comparable to the most stringent astrophysical limits; in particular, the high-energy selection (8.0─16.8 MeV) provides a sensitivity that is competitive with current results, while the full-energy window remains primarily limited by near-reactor backgrounds.

Keywords: Neutrino oscillations, Solar neutrinos, Particle astrophysics
Turbulence Properties of Corotating Interaction Regions at 1 au: A Comprehensive Superposed Epoch Analysis. We perform a comprehensive superposed epoch analysis of more than 200 corotating interaction regions (CIRs) using WIND spacecraft observations at 1 au. The stream interfaces are identified by minimum variance analysis, and turbulence properties are evaluated using wavelet transforms over a wide range of temporal scales. The analysis of normalized cross helicity (σc) and normalized residual energy (σr) reveals distinct turbulence behaviors across frequencies. The spectral indices of both magnetic and velocity fluctuations smoothly transition from steeper in the slow wind to shallower in the fast wind, while a localized steepening of the velocity spectra near the interface indicates enhanced dissipation due to compression. Across broad frequency bands, σc shows a clear dip at the stream interface—signifying increased inward Alfvén wave energy—whereas σr displays a peak─valley─peak structure mainly driven by large-scale velocity shear. In lower-frequency ranges, velocity shear artificially enhances velocity fluctuation energy, producing strong peaks in σr, while higher-frequency ranges show a smooth increase of σr from slow wind to fast wind. Nearly half of the analyzed CIRs are accompanied by a heliospheric current sheet (HCS), with many HCSs closely aligned with the stream interface, suggesting an intrinsic link between the two structures. Our findings offer valuable clues for reconciling discrepancies among earlier observational and simulation studies, and provide new insight into how compression and velocity shear modulate solar wind turbulence near CIRs.

Keywords: Interplanetary turbulence, Solar wind, Corotating streams
PHR J1724-3859: A Bipolar Planetary Nebula in Open Cluster Trumpler 25. Planetary nebulae (PNs) studies are essential for understanding the late stellar evolution of low-to-intermediate mass stars. PNs in open clusters (OC) are rare but valuable since their study directly links their properties to those of their progenitors, something that cannot be achieved for field PNs. Here, we report the identification of one more OC-PN association to add to the small sample of, now, five pairs. The physical properties of the host cluster, PN, and its central star (CSPN) have been explored using high and intermediate-resolution spectral and deep photometric data. The close agreement of the radial velocities of the PN and host cluster, together with concordance of reddening and distance, shows that the PN PHR J1724-3859 is highly likely to be physically associated with the OC Trumpler 25. Deep photometric data allowed clear identification of the CSPN. We find a CSPN effective temperature of around 250 kK and a nebular kinematic age of 23 kyr, both at the extreme end, like the other members of this small class. The progenitor and final CSPN masses have been estimated to be 5.12 −0.15+0.16  M⊙and 0.95 ± 0.12 M⊙ respectively. These latest results agree with the emerging trend for our other OC-PNs, falling below, but approximately parallel to, the latest initial-to-final-mass relation estimates derived from cluster white dwarfs, and have important implications for stellar evolution models. All OC-PNs also possess some other common properties (e.g., all are Type I PNs and bipolars) to be explored in future studies. *Based on observations made with the Southern African Large Telescope (SALT), the ESO Very Large Telescope (VLT), and the Gemini telescope.

Keywords: Open star clusters, Planetary nebulae
Formation and Disruption of Resonant Chains of Super-Earths: Secular Perturbations from Outer Eccentric Embryos. Recent observations have revealed the distribution of orbital period ratios of adjacent planets in multiple super-Earth systems and how these distributions change with time. The aim of this study is to clarify under what conditions the observed features of orbital period ratios of super-Earths can be explained, and to identify what causes the dynamical instability of super-Earths captured into resonant chains. We perform N-body simulations for 100 Myr that follow the formation and orbital evolution of super-Earths originating from a ring of planetary embryos at 1 au from the star. The simulations show that super-Earths undergo inward migration in the disk and are captured into mean-motion resonances with their neighbors. As a result, several resonant pairs form a resonant chain. After disk dispersal, some of these chains become dynamically unstable. In such cases, the final distribution of orbital period ratios and their time evolution can be consistent with recent observations. The instabilities of resonant chains are likely triggered by secular perturbations from embryos that remain on outer orbits beyond 1 au, indicating that not only giant planets but also small embryos can disrupt the resonances among inner super-Earths. We therefore further investigate the secular perturbations from outer embryos using analytic formulas and additional orbital calculations. We discuss the conditions required to excite the eccentricities of inner super-Earths on a timescale of about 100 Myr. These conditions include the need for large eccentricities of the outer embryos, as well as constraints on their masses and semimajor axes.

Keywords: Exoplanet dynamics, Exoplanet migration, Exoplanet formation, N-body simulations
ALMASOP: Inner-envelope Structures of Protostars Driving Nascent Jets. Protostellar jets provide valuable insight into the evolutionary stage and formation history of star-forming cores in their earliest phases. We investigated the inner envelope structures of three extremely young protostars, selected for having the shortest dynamical timescales in their outflows and jets. Our analysis is based on Atacama Large Millimeter/submillimeter Array observations of the N2D+, DCO+, DCN, C18O, CH3OH, and H2CO lines, along with 1.3 mm continuum data, obtained at two spatial resolutions of ∼500 and 150 au. By examining molecular depletion and sublimation patterns and emission extents at core-scale and outflow rotational temperatures, we assessed the relative evolutionary stages of the three sources. In G208.68─19.20N1, the absence of N2D+ toward the core—despite a semi-ringlike distribution—and the presence of bright DCN and DCO+ emission cospatial with C18O indicate a warmer envelope, possibly suggesting a more advanced evolutionary state. In contrast, G208.68─19.20N3 shows no dense central structures in C18O, DCN, DCO+, or N2D+, with emission instead appearing scattered around the continuum and along large-scale filaments, consistent with a likely younger stage than G208.68─19.20N1. The third source, G215M, exhibits compact C18O emission at the continuum peak but spatially extended N2D+, DCN, and DCO+ along the continuum, pointing to a cooler envelope and likely the youngest stage among the three. This comparative analysis across three protostars demonstrates the effectiveness of molecular tracers for evolutionary staging, though variations in luminosity or accretion may also shape chemical morphologies. These results highlight the promise of broader surveys for advancing our understanding of early protostellar evolution.

Keywords: Circumstellar envelopes, Stellar jets, Protostars, Astrochemistry, Star formation, Submillimeter astronomy
Bridging Quasars and Little Red Dots: Insights into Broad-line Active Galactic Nuclei at z = 5─8 from the First JWST COSMOS-3D Dataset. We report the discovery of 13 broad-line active galactic nuclei (AGNs) at z = 5─8 from the first 10% of JWST Cycle 3 Treasury Program COSMOS-3D. These AGNs are identified by their broad Hα or Hβ emission lines through NIRCam grism slitless spectroscopy. One object at z = 7.646 with broad Hβ emission has an F444W magnitude of 23.6 mag, making it one of the brightest z &gt; 7.5 broad-line AGNs yet known. Among the 13 AGNs, 10 objects exhibit reddened optical continua with slopes βopt &gt; 0. The remaining three resemble UV-luminous quasars at similar redshift but with βopt less blue than those of typical unobscured quasars. We also obtain MIRI photometry (7.7─18 μm) for two AGNs and place strong constraints on their rest-frame near-IR spectral energy distribution. We find no significant variability in the rest-frame UV by comparing the COSMOS-3D and COSMOS-Web F115W images taken apart by 60 days in the rest-frame. We compute the Hα luminosity function (LF) at z ≍ 5─6 and find potential redshift evolution compared to z ≍ 4─5. We also derive the Hβ LF at z ∼ 8 by combining our sample with those from the literature. The broad Hβ emitters in this work suggest a number density 2 orders of magnitude higher than that predicted by the quasar LF based on rest-frame UV-selected samples. As a preview, our work showcases the ability of the COSMOS-3D grism survey to provide a complete view of the properties, growth, and evolution of bright broad-line AGNs at z &gt; 5.

Keywords: Supermassive black holes, Active galactic nuclei, High-redshift galaxies
Active Galactic Nucleus Feedback in an Elliptical Galaxy. IV. The Importance of the Jet─Wind Coupling. This is the fourth paper of our series investigating the effects of active galactic nucleus (AGN) feedback in the evolution of an elliptical galaxy using the MACER framework. While previous works considered only AGN radiation and wind, we now add jet feedback. The values of the jet parameters are taken from small-scale general relativity MHD simulations of black hole accretion. We run three models: FullFeedback, JetOnly, and WindOnly. Time-averaged star formation rates are 10−1, 10−2, and 10−3 M⊙ yr−1 in JetOnly, WindOnly, and FullFeedback, respectively. Despite the higher jet power, jet feedback is less efficient than wind due to a small opening angle and low momentum flux. The much lower star formation rate in FullFeedback indicates nonlinear coupling between the jet and wind, with stronger suppression than the linear sum. The AGN energy dissipation efficiency values (fraction of injected kinetic energy dissipated via turbulence and shock) are 0.64 (FullFeedback), 0.48 (WindOnly), and 0.26 (JetOnly). In the FullFeedback model, the wind─jet shear results in Kelvin─Helmholtz instability, driving stronger turbulence that effectively converts AGN kinetic energy into heating.

Keywords: Galaxy quenching, Galaxy evolution
Probing Spin─Orbit Resonances with the Binary Black Hole Population. Measurements of the binary black hole (BBH) spin distribution from the growing catalog of gravitational-wave observations can help elucidate the astrophysical processes shaping the formation and evolution of these systems. Spin─orbit resonances are one process of interest, in which the component spin vectors and the orbital angular momentum align into a common plane and jointly precess about the total angular momentum of the system. These resonances, which occur preferentially in systems formed via isolated binary evolution with strong tidal effects, lead to excesses in the distribution of the azimuthal angle between the projections of the component spin vectors onto the orbital plane at ϕ12 = 0, ±π. In this work, we conduct the first hierarchical analysis modeling the population-level distribution of ϕ12 simultaneously with the other mass and spin parameters for simulated BBH populations to determine whether spin─orbit resonances can be reliably constrained. While we are unlikely to find definitive evidence for spin─orbit resonances with a population of the size expected by the end of the LIGO-Virgo-KAGRA fourth observing run, we correctly recover the various ϕ12 distributions we simulate within uncertainties. We find that we can place meaningful constraints on the relative excesses at ϕ12 = 0, ±π, which encodes information about binary mass transfer. We can also distinguish between fully isotropic spin angle distributions and those with features in the spin azimuth and tilt distributions. Thus, we show that population-level measurements of the ϕ12 distribution offer a reliable, novel way to probe binary formation channels, dynamics, and mass transfer with gravitational-wave observations.

Keywords: Gravitational wave sources, Spin-orbit resonances, Astrophysical black holes
Efficiency of Hydrodynamic Atmospheric Escape in Hot Jupiters and Super-Earths. We develop a flexible one-dimensional code to model the escape of hydrogen and helium from a hot Jupiter as a result of photoionization from extreme-ultraviolet (EUV) radiation. We include stellar spectrum heating and ionization, radiative cooling by Lyα and  H3+ , heat conduction, tidal gravity, and a H─He reaction network, and account for the secondary ionization of species by photoelectrons. For a fiducial hot Jupiter, we uncover a three-layer structure: an  H3+ -cooled layer of molecular hydrogen at the base, enveloped by a Lyα-cooled layer of neutral hydrogen, which transitions into an ionized wind layer that is cooled by adiabatic expansion. The highest spectral energy photons are deposited in the molecular layer, where, after accounting for energy loss via photoelectrons and ionization,  H3+  is a substantial radiative coolant. We run a grid of models, varying the distance of our fiducial planet from the star. We find that heat conduction at the base starts to have an effect at distances ≳0.2 au, increasing the  H3+  cooling relative to the EUV input flux. At increasing stellocentric distances, the outflow becomes increasingly more neutral. The neutral hydrogen starts to decouple from the ionized outflow, free-streaming out. In pure H─He mini-Neptune/super-Earth simulations, the outflows are significantly cooler, allowing molecules to survive throughout the outflow, pointing toward the likely importance of molecular cooling in determining whether these planets can maintain massive atmospheres. The analysis in this paper provides a framework for understanding the impact of molecular radiative cooling on atmospheric outflows.

Keywords: Hot Jupiters, Super Earths, Exoplanet atmospheres
Scalable Stellar Parameter Inference Using Python-based LASP: From CPU Optimization to GPU Acceleration. To enhance the efficiency, scalability, and cross-survey applicability of stellar parameter inference in large spectroscopic datasets, we present a modular, parallelized Python framework with automated error estimation, built on the LAMOST Atmospheric Parameter Pipeline (LASP) originally implemented in IDL. Rather than a direct code translation, this framework refactors LASP with two complementary modules: LASP-CurveFit, a new implementation of the LASP fitting procedure that runs on a CPU, preserving legacy logic while improving data I/O and multithreaded execution efficiency; and LASP-Adam-GPU, a GPU-accelerated method that introduces grouped optimization by constructing a joint residual function over multiple observed and model spectra, enabling high-throughput parameter inference across tens of millions of spectra. Applied to 10 million LAMOST spectra, the framework reduces runtime from 84 to 48 hr on the same CPU platform and to 7 hr on an NVIDIA A100 GPU, while producing results consistent with those from the original pipeline. The inferred errors agree well with the parameter variations from repeat observations of the same target (excluding radial velocities), while the official empirical errors used in LASP are more conservative. When applied to DESI DR1, our effective temperatures and surface gravities agree better with APOGEE than those from the DESI pipeline, particularly for cool giants, while the latter performs slightly better in radial velocity and metallicity. These results suggest that the framework delivers reliable accuracy, efficiency, and transferability, offering a practical approach to parameter inference in large spectroscopic surveys. The code and DESI-based catalog are available via DOI: 10.12149/101679 and DOI: 10.12149/101675, respectively.

Keywords: Astronomy software, Fundamental parameters of stars, Surveys, Radial velocity, Astronomy data analysis, GPU computing