Sazuna/UAT_keywords huggingface dataset:
Examining the Radial Evolution of a Corotating Interaction Region Observed at STEREO-A and MAVEN. Corotating interaction regions (CIRs) are long-lasting solar wind structures that persist over multiple solar rotations. These structures accelerate particles throughout the heliosphere and can impart significant energy onto planetary ionospheres and magnetospheres. Understanding how CIRs and their associated energetic particles evolve radially with heliocentric distance is of great interest and can give insight into acceleration mechanisms that occur within these structures. CIR solar wind and particle properties have been examined at numerous heliocentric distances but have been largely unexplored at Mars. We examine the properties of a CIR observed over two Carrington rotations by the Solar Terrestrial Relations Observatory (STEREO)-A at 1 au and the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft at 1.5 au. This CIR was observed during near-radial alignment of the spacecraft, allowing for the exclusion of significant longitudinal variations in the CIR's properties. We find that during both rotations, the scaled solar wind density and interplanetary magnetic field are slightly higher at MAVEN than measurements at STEREO-A, and the CIR compression occurs over similar periods at both spacecraft during each event. Suprathermal particle enhancements are observed at both spacecraft during both passes of the CIR. Variations in the particle spectra between observations indicate suprathermal particle acceleration at both spacecraft, with higher-energy populations observed at 1.5 au compared to 1 au. Spectral anisotropies observed at MAVEN also indicate a combination of local and nonlocal particle acceleration, further demonstrating that the acceleration mechanisms associated with CIRs are complex and evolve with heliocentric distance.

Keywords: Solar energetic particles, Mars, Corotating streams
Distinct Acceleration Relations of Galaxies and Galaxy Clusters from Hyperconical Modified Gravity. General relativity (GR) is the most successful theory of gravity, with great observational support on local scales. However, to keep GR valid over cosmic scales, some phenomena require the assumption of exotic dark matter, especially the cosmic expansion history and flat rotation curves of galaxies. Their radial acceleration relation (RAR) indicates a tight correlation between the dynamical mass and the baryonic mass. This suggests that galactic observations could be better explained by modified gravity theories without exotic matter. Modified Newtonian dynamics (MOND) is an alternative theory that was originally designed to do exactly this using a new fundamental acceleration scale, a0, the so-called Milgromian parameter. However, this nonrelativistic model lacks the flexibility needed to account for the wide variety of observed phenomena. In contrast, a relativistic MOND-like gravity naturally emerges from the hyperconical model, which derives a fictitious acceleration compatible with observations. We analyze the compatibility of the hyperconical model with respect to distinct RAR observations of 10 galaxy clusters obtained from HIFLUGCS and 60 high-quality SPARC galaxy rotation curves. The results show that a general relation can be fitted to most cases with only one or two parameters, with an acceptable χ2 and p-value. These findings suggest a possible way to complete the proposed modification of GR on cosmic scales.

Keywords: Galaxy clusters, Galaxy dynamics, Modified Newtonian dynamics
Classifying Metal-poor Stars with Machine Learning Using Nucleosynthesis Calculations. We apply the capabilities of machine learning (ML) to discern patterns in order to classify metal-poor stars. To do so, we train an ML model on a bank of nucleosynthesis calculations derived from hydrodynamic simulations for events such as neutron star mergers where the rapid (r) neutron capture process can take place. Likewise, we consider a bank of calculations from simulations of the slow (s) neutron capture process. We explore the performance of both a binary classifier and a one-class classifier. We demonstrate that our ML models do well overall in recognizing the s process from the r process, and after training on theoretical calculations, ML stellar assignments match conventional labels 87% of the time. We highlight that this method then points to stars that could benefit from additional observational measurements. We then apply the one-class classifier to numerous cases on which it did not train, including i-process stars, and a few nucleosynthesis predictions for the i process in rapidly accreting white dwarfs and r process in MHD supernovae. We demonstrate that the ML assigns some of the presently considered i-process stars to instead be of r or s in origin but likewise finds stars currently labeled as s to be potentially more aligned with i enrichment. This first application of ML to classify metal-poor star enrichment using theoretical nucleosynthesis calculations reveals the promise, and some challenges, associated with this new data-driven path forward.

Keywords: Nucleosynthesis, Neural networks, Stellar abundances, R-process, S-process
Observational Analysis of Multithermal Counterstreaming Flows in a Forming Filament and Their Relationship with Local Heating at Filament Footpoints. Utilizing high-resolution imaging and spectroscopic observations from the New Vacuum Solar Telescope, the Interface Region Imaging Spectrograph, and the Solar Dynamics Observatory, we investigated the nature and origin of counterstreaming flows within a forming active region filament. The ever-present counterstreaming flows observed within the filament are identified as interleaved unidirectional mass flows in opposing directions occurring in neighboring threads. Multiwavelength observations corroborate the multithermal nature of these counterstreaming flows: the cool Hα component flows at about 10‑20 km s‑1, while the warm ultraviolet and extreme-ultraviolet components reach 40–70 km s‑1. The Si IV 1400 Å line reveals significant microturbulence in the filament's counterstreaming flows, with a nonthermal velocity width of ∼40 km s‑1. These multithermal flows emanate from compact brightenings at the filament's ends, manifesting as small-scale, collimated upflows at their nascent phase. They continuously inject both chromospheric and transition region plasma into the filament channel, thereby feeding the counterstreaming flows. At their base, the Si IV and C II spectral lines show pronounced line broadening and intensity enhancements, indicating significant localized chromospheric heating. Additionally, numerous small-scale photospheric flux emergence and cancellation events, with a magnitude of ∼1017 Mx, are detected near their base. We suggest that such weak magnetic-field activities, possibly associated with unresolved magnetic reconnection events, drive these persistent upflows and localized footpoint heating. This work elucidates the multithermal origin of counterstreaming flows within a forming filament and provides evidence of localized chromospheric heating at the filament footpoints.

Keywords: Jets, Solar magnetic reconnection, Solar active region filaments, Solar active regions, Solar physics, Solar filaments, Solar activity
Recoiling Black Hole Candidates from Spatially Offset Broad Emission Lines in MaNGA. From the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, we identify 14 off-nuclear broad (FWHM &gt; 1000 km s−1) Hα and/or Hβ emission line sources that indicate spatially offset active galactic nuclei (AGN) candidates. In addition to massive black holes (MBHs) in ongoing galaxy mergers, this selection can also find MBHs that have been ejected from the host galaxy nucleus due to MBH binary coalescence and asymmetric gravitational wave emission or the dynamical "slingshot" mechanism. Recoiling/slingshot MBHs are predicted to affect coevolution between MBHs and their host galaxies, and they are observational tracers of past binary MBH mergers and gravitational wave emission. This is the first systematic search through an integral field spectroscopy survey for ejected MBHs to enable uniform constraints on their surface densities. We find that 42% (6/14) have optical image counterparts consistent with galaxy stellar cores from infalling MBHs before the close binary MBH stage. The remaining 58% (8/14) have large broad line luminosities relative to their stellar core mass upper limits (∼2 times larger than for central AGN), suggesting merger-driven MBH accretion enhancements or potentially ejected MBHs. The signatures of AGN-ionized narrow emission lines for recoil/slingshot candidates are weaker by 68%, which is consistent with the ejected MBH scenario. The broad line projected velocity offsets range from ∼10 to 600 km s−1 and suggest motion within the host galaxy potentials. Finally, the implied recoiling MBH surface density upper limit is consistent with predictions that assume random spin orientations in MBH binaries.

Keywords: Supermassive black holes, Emission line galaxies, Active galactic nuclei, Gravitational waves, Galaxy mergers, Spectroscopy
A Deep, High-angular-resolution 3D Dust Map of the Southern Galactic Plane. We present a deep, high-angular-resolution 3D dust map of the southern Galactic plane over 239° &lt; l &lt; 6° and ∣ b∣ &lt; 10° built on photometry from the DECaPS2 survey, in combination with photometry from VISTA Variables in the Via Lactea, the Two Micron All Sky Survey, and "Unofficial" Wide-field Infrared Survey Explorer and parallaxes from Gaia Data Release 3 where available. To construct the map, we first infer the distance, extinction, and stellar types of over 700 million stars using the BRUTUS stellar inference framework with a set of theoretical MESA Isochrone and Stellar Tracks (MIST) stellar models. Our resultant 3D dust map has an angular resolution of  1' , roughly an order of magnitude finer than existing 3D dust maps and comparable to the angular resolution of the Herschel 2D dust emission maps. We detect complexes at the range of distances associated with the Sagittarius-Carina and Scutum-Centaurus arms in the fourth quadrant, as well as more distant structures out to a maximum reliable distance of d ≍ 10 kpc from the Sun. The map is sensitive up to a maximum extinction of roughly A  V  ≍ 12 mag. We publicly release both the stellar catalog and the 3D dust map, the latter of which can easily be queried via the Python package dustmaps. When combined with the existing Bayestar19 3D dust map of the northern sky, the DECaPS 3D dust map fills in the missing piece of the Galactic plane, enabling extinction corrections over the entire disk ∣b∣ &lt; 10°. Our map serves as a pathfinder for the future of 3D dust mapping in the era of LSST and Roman, targeting regimes accessible with deep optical and near-infrared photometry but often inaccessible with Gaia.

Keywords: Interstellar dust, Milky Way Galaxy, Surveys
DOLPHIN: A Fully Automated Forward-modeling Pipeline Powered by Artificial Intelligence for Galaxy-scale Strong Lenses. Strong gravitational lensing is a powerful tool for probing the internal structure and evolution of galaxies, the nature of dark matter, and the expansion history of the Universe, among many other scientific applications. For almost all of these science cases, modeling the lensing mass distribution is essential. For that, forward modeling of imaging data to the pixel level is the standard method used for galaxy-scale lenses. However, the traditional workflow of forward lens modeling necessitates a significant amount of human investigator time, requiring iterative tweaking and tuning of the model settings through trial and error. An automated lens-modeling pipeline can substantially reduce the need for human investigator time. In this paper, we present DOLPHIN, an automated lens-modeling pipeline that combines artificial intelligence with the traditional forward-modeling framework to enable full automation of the modeling workflow. DOLPHIN uses a neural network model to perform visual recognition of the strong lens components, then autonomously sets up a lens model with appropriate complexity and fits the model with the modeling engine, LENSTRONOMY. Thanks to the versatility of LENSTRONOMY, DOLPHIN can autonomously model both galaxy─galaxy and galaxy─quasar strong lenses.

Keywords: Strong gravitational lensing, Astronomy data modeling, Astronomy software, Neural networks
Lopsided and Bulging Distribution of Satellites around Paired Halos. II. 3D Analysis and Dependence on Projection and Selection Effects. We use the Illustris-TNG300 simulation to investigate the anisotropic distribution of subhalos in/around dark matter halo pairs. We measure the position angle (θ) of each subhalo by the angle between the line connecting it to the nearest host halo and the line connecting the paired halos, and examine  P(cosθ)  (the distribution of  cosθ  of all subhalos) for halo pairs with various separations (dsep), primary halo masses (Mp), and secondary-to-primary halo mass ratios (Ms/Mp). We find that  P(cosθ)  generally exhibits a combined result of two distinct features: the "bulging" distribution characterized by an overabundance along the pairwise direction, and the "lopsided" distribution showing an overabundance in the region between the paired halos. The bulging signal is stronger for halo pairs with larger dsep and smaller Mp, while the lopsidedness strengthens as Mp increases. Both signals depend weakly on Ms/Mp, and are primarily contributed by subhalos that are relatively distant from the host halos. Remarkably, these measurements can be broadly reproduced by the overlap effect, provided the spatial alignment of the halos is properly taken into account. Our findings suggest distinct origins: lopsidedness arises from simple halo overlap, while bulging reflects alignment with large-scale filaments. We examine the impact of projection and selection effects by conducting the same analysis in two dimensions and in a mock catalog that replicates the selection effects of the Sloan Digital Sky Survey galaxy sample. We find that the 3D-to-2D projection significantly suppresses the bulging distribution, with particularly strong effects at large dsep, small Mp, and large Ms/Mp.

Keywords: Galaxy dark matter halos, Galaxy pairs, N-body simulations, Large-scale structure of the universe
Spatially Resolved [O III] Emission Line Kinematics of Reverberation-mapped Active Galactic Nuclei with the Keck Cosmic Web Imager. We present optical integral-field spectroscopic data of ten nearby (0.02 ≤ z ≤ 0.05) Seyfert 1 galaxies taken with the Keck Cosmic Web Imager. We map the spatially resolved kinematics of the [O III] gas and stars, and investigate the alignments between their global kinematic position angles (PAs). Large-scale gas motions are primarily dominated by rotation and are kinematically aligned with the stars (∆PA ≤ 30°). However, eight galaxies exhibit nonrotational kinematic signatures (e.g., kinematic twists, possible outflows) in their ionized gas velocity fields near the nucleus. We compare aperture-wide measurements of the gas and stellar velocity dispersions (σgas and σ⋆) to test the use of the width of the [O III] line core as a surrogate for σ⋆. Direct comparisons between σgas and σ⋆ show that σgas tends to underestimate σ⋆, and thus is not a reliable tracer of σ⋆ for our selected galaxies. We measure the extent of the narrow-line region (NLR) using several definitions, resulting in sizes of ∼0.1─10 kpc. For a given [O III] luminosity, our NLR sizes derived from the [O III]/Hβ flux ratio or an [O III] isophotal radius are an order of magnitude larger than those measured from past imaging data.

Keywords: Stellar kinematics, Emission line galaxies, Seyfert galaxies, Active galactic nuclei, Galaxy kinematics, Galaxy spectroscopy
Blowout Expansion of Overlying Coronal Loops and Subsequent Filament Eruption: AIA and RHESSI Observations. We present a comprehensive multiwavelength analysis of a coronal mass ejection (CME) on 2014 January 8 from the active region (AR) NOAA 11947 by analyzing the data from Atmospheric Imaging Assembly (AIA) on board Solar Dynamics Observatory, RHESSI, and Hiraiso Radio Spectrograph. The CME is associated with an M3.6 flare and filament eruption. Observations from the AIA 171 Å images reveal the origin of pre-CME arcade ≈1 hr prior to the eruptive event. Before the onset of event, the hot AIA 131 and 94 Å images exhibit an existence of a hot flux rope, which on eruption results in the activation and eruptive expansion of the pre-CME coronal arcade. The eruptive process of pre-CME arcade consists of a slow rise evolution with a speed ≈3 km s‑1, "arcade-to-bubble" transformation, and blowout expansion of the CME-bubble with a fast speed of ≈400 km s‑1. A differential emission measure analysis suggests the presence of multithermal plasma in the bubble-structure and strong plasma heating at the core of the AR. A blowout expansion of CME is accompanied with multiple type III and a split-band type II radio bursts in association with X-ray emission up to 50 keV energies from its source region. Our observations reveal that the formation and expansion of the CME-bubble serve as the earliest signatures of the CME, capturing its development in the low corona. Concurrent X-ray and radio emissions further highlight the critical role of large-scale magnetic reconnection in powering both the flare emissions and the early evolution and dynamics of the CME.

Keywords: Radio bursts, Solar flares, Solar coronal mass ejections, Solar filaments
Revisiting the Gas Dynamics of Henize 2─10: Possible Drivers of the Starburst. The triggers of starburst episodes are a key component to our understanding of the baryon cycle in galaxies. Galaxy mergers are a commonly suggested catalyst for starbursts, but once the galaxies coalesce into a single kinematically disturbed system, their merger history can be difficult to assess. This is particularly true for dwarf galaxies, which are expected to dominate the merger rate at all redshifts due to their large numbers. One such dwarf galaxy undergoing an enigmatic starburst episode is Henize 2─10, which appears to be isolated. Possible scenarios that might have caused the starburst episode include a previous merger or stochastic processes within the galaxy itself, such as self-regulation via feedback processes. We present new Very Large Array 21 cm observations and unpublished archival Combined Array for Research in Millimeter-wave Astronomy CO data to investigate the dynamical state and star formation activity in the galaxy. We do not detect an H I tail consistent with the structure reported by H. A. Kobulnicky et al. (1995), which was suggested as evidence for a merger or interaction, but rather, these new observations indicate an extended H I distribution. We also find that the H I appears dynamically decoupled from an extended CO feature (inferred to be a tidal tail in previous work), suggesting large-scale dynamical processes of some type are affecting the gas in this system. We provide a metaanalysis of available results to enhance our understanding of what might be triggering the starburst episode in Henize 2─10, and speculate that the large CO feature could be falling into the galaxy and potentially trigger starburst activity.

Keywords: Starburst galaxies, Blue compact dwarf galaxies, Neutral hydrogen clouds, Galaxy kinematics, Galaxy mergers, Interstellar medium
COSMOS-Web: MIRI Data Reduction and Number Counts at 7.7 μm Using JWST. The COSMOS-Web survey is the largest JWST Cycle 1 General Observer program, covering a contiguous ∼0.54 deg2 area with NIRCam imaging in four broadband filters and a noncontiguous ∼0.2 deg2 with parallel MIRI imaging in a single broadband filter, F770W. Here we present a comprehensive overview of the MIRI imaging observations, the data reduction procedure, the COSMOS-Web MIRI photometric catalog, and the first data release including the entire COSMOS-Web MIRI coverage. Data reduction primarily relies on the JWST Science Calibration Pipeline, supplemented by custom background subtraction to mitigate prominent instrumental artifacts and sky background within the MIRI images. We reach 5σ (point source) limiting depths (mF770W ∼ 25.51 based on r ∼ 0 .″ 3 circular apertures) that are significantly better than initial expectations. Using the images provided in this release, we construct a photometric catalog and compare the F770W flux densities to the Spitzer/IRAC CH4 measurements from the COSMOS2020 catalog (for CH4 detections with signal-to-noise ratio S/N &gt; 5). We find that these are in reasonable agreement with a small median offset of &lt;0.05 mag. We also derive robust 7.7 μm number counts spanning five orders of magnitude in flux (∼0.2─2300 μJy)—making COSMOS-Web the only JWST survey to date to sample such a large flux range—which are in good agreement with estimates from other JWST and IRAC surveys.

Keywords: Astronomy data reduction, James Webb Space Telescope, Galaxy evolution, Infrared sources, Galaxy counts, Infrared photometry
Pitch-angle Focusing and Scattering of TeV Galactic Cosmic Rays Propagating in Local Interstellar Magnetic Fields. We use Tibet ASγ anisotropy data for 4 TeV cosmic rays to investigate the properties of the pitch-angle focusing and diffusion caused by the interstellar magnetic field and turbulence. The pitch-angle distribution (PAD) in the local interstellar medium is reconstructed from the anisotropy map using Liouville mapping. Under the diffusion approximation, we found that the expected pitch-angle diffusion coefficient is an asymmetric function of pitch angle. Without organized magnetic/cross-helicities of interstellar magnetic field turbulence, such an asymmetry can be interpreted as evidence of focusing by a nonuniform magnetic field. A model incorporating a symmetric pitch-angle diffusion coefficient and focusing effects reproduces the observed PAD. It also indicates that the length of the magnetic field inhomogeneity is a few times the parallel mean free path of TeV particles, and that the interstellar field weakens along the field direction into the northern Galactic halo. The inferred pitch-angle diffusion coefficient might suggest scattering by compressible magnetic field turbulence. Additionally, we estimate that the parallel and perpendicular flux gradients have lengths ∼1.72κ29 kpc and ∼7.76 pc, respectively, where κ29 is the spatial diffusion coefficient in units of 1029 cm2 s−1. The lack of a significant observed diffusion flow perpendicular to the local magnetic field puts an upper bound on the perpendicular-to-parallel local diffusion coefficient ratio of 0.00045/κ29. Moreover, we show that the temporal rate of change is no more than 7.08 × 10−7/κ29 yr−1 in relative intensity.

Keywords: Galactic cosmic rays, Interstellar magnetic fields