Sazuna/UAT_keywords huggingface dataset:
Taming the Tarantula: How Stellar Wind Feedback Shapes Gas and Dust in 30 Doradus. Observations of massive star-forming regions show that classical stellar wind models overpredict the luminosity of the X-ray-emitting gas, indicating a significant fraction of wind energy is lost. In this paper, we present a multiwavelength analysis of the giant H II region 30 Doradus and its central star cluster R136 using 2 Ms of Chandra data, combined with James Webb Space Telescope and Hubble Space Telescope imaging and Spitzer spectral energy distributions, to investigate how the energy of the hot gas is lost through turbulent mixing, radiative cooling, and physical leakage. We compare the spatial and spectral properties of the hot gas with those of the warm ionized gas and dust. We find no significant correlation between the dust and hot gas temperatures, suggesting they are not directly coupled and that the dust resides in the swept-up shells where it is heated radiatively. Hα and X-ray surface brightness profiles show that the X-rays peak interior to the Hα shells, demonstrating partial confinement of the hot gas. The fragmented shell structure and the bright X-ray interior that declines near the Hα shell reflect efficient cooling from turbulent mixing at the hot─cold interface. We compare against recent simulations of stellar-feedback-driven bubbles, which have broad agreement with the morphology of the X-ray and Hα emission, but the simulations produce a dip in the interior X-ray surface brightness and a lack of hard X-rays compared to the observations. These differences may suggest thermal conduction is important because mass-loading of the hot bubble could reproduce the X-ray observables.

Keywords: Star formation, H II regions, Interstellar medium, Stellar wind bubbles
Spin-down Changes in PSR B0540-69 Induced by a Drift of the Magnetic Axis. The dynamics of the solid crust + magnetic field lines of pulsars is a much debated issue and remains unsettled after 50 yr. Some pieces of evidence have emerged to complete and confirm theoretical calculations and expectations. We discuss in the present work an interpretation of the behavior of the "Crab Twin" pulsar PSR B0540-69 in terms of the evolution of the magnetic field/quakes, connecting the behavior of the braking index with the underlying platelet drift and sudden discontinuous rearrangement (fast-slip) and long-term ones (slow-slip events), suggested by analogy with the existing theoretical picture observed in the Earth's crust. The relationship of this scenario with permanent torque-changing glitches seen in the Crab and other young pulsars, and a set of similar events in the same object and others, is addressed. We conclude that this physical approach is in principle consistent with all these sudden events and point out future work to clarify the whole picture.

Keywords: Neutron stars, Neutron star cores, Pulsars
Exploring Cosmological Constraints of the Void-lensing Cross Correlation in the CSST Photometric Survey. We investigate the cosmological constraints from the void-lensing cross correlation assuming the wCDM model for the Chinese Space Station Survey Telescope (CSST) photometric survey. Using Jiutian simulations, we construct a mock galaxy catalog to z = 3 covering 100 deg2, which incorporates the instrumental and observational effects of the CSST. We divide the galaxy sample into seven photometric-redshift (photo-z) tomographic bins and identify two-dimensional voids within each bin using the Voronoi tessellation and watershed algorithm. We measure the angular cross-power spectrum between the void distribution and the weak lensing signal, and estimate the covariance matrix via jackknife resampling combined with the pseudo-Cℓ approach to account for the partial sky correction. We employ the Halo Void Dust Model to model the void-matter cross-power spectrum and adopt the Markov Chain Monte Carlo technique to implement the constraints on the cosmological and void parameters. We find that our method can accurately extract the cosmological information, and the constraint accuracies of some cosmological parameters from the void-lensing analysis are comparable to or even better than the weak-lensing-only case. This demonstrates that the void lensing serves as an effective cosmological probe and a valuable complement to galaxy photometric surveys, particularly for the Stage IV surveys targeting the high-redshift Universe.

Keywords: Cosmology, Voids, Large-scale structure of the universe, Cosmological parameters
When IIb Ceases To Be: Bridging the Gap between IIb and Short-plateau Supernovae. Hydrogen-rich supernovae (SNe) span a range of hydrogen envelope masses at core collapse, producing diverse light curves from extended plateaus in Type IIP SNe to double-peaked Type IIb SNe (SNe IIb). Recent simulations predict a continuous sequence of light-curve morphologies as hydrogen is removed, with short-plateau (SP; plateau durations ≍50─70 days) SNe emerging as a transitional class. However, the observational boundary between types IIb and SP remains poorly defined, and thus far unobserved. We report on extensive photometric and spectroscopic follow-up of SN 2023wdd and SN 2022acrv, two candidate transitional events on the low-mass end of the SP class. Both exhibit weak, double-peaked light curves, which we interpret as exceptionally short plateaus (10─20 days), and hybrid spectral features: persistent Hα absorption with He I contamination, but without the helium dominance characteristic of SNe IIb. Using analytic shock-cooling models and numerical light-curve fitting, we estimate H-rich envelope masses of ∼0.6─0.8 M⊙—significantly larger than canonical IIb values (≲0.1 M⊙) but consistent with the ∼0.9 M⊙ threshold predicted for short-plateau behavior. Although the progenitor radii inferred from analytic and numerical methods differ by factors of 2─5, envelope mass estimates are consistent across approaches. Comparisons to well-studied Type IIb (SN 2016gkg, SN 2022hnt), SP (SN 2023ufx, SN 2006ai, SN 2016egz, SN 2006Y), and Type II (SN 2023ixf, SN 2013ej) SNe suggests a monotonic relationship between hydrogen envelope mass and plateau length, consistent with analytic and numerical expectations. These findings provide additional evidence for a continuous distribution of envelope stripping in H-rich core-collapse progenitors, and place SN 2023wdd and SN 2022acrv along the IIb─SP boundary.

Keywords: Core-collapse supernovae
Long-term (250 yr) Hydrodynamical Simulation of the Supermassive Black Hole Binary OJ 287. With upcoming facilities capable of detecting photometric and gravitational wave signals from supermassive black hole (SMBH) binaries, studying their long-term accretion-driven variability is timely. OJ 287 is a bright, nearby (z = 0.3), and well-studied candidate for an SMBH binary. As such, it is an excellent case study for how binary dynamics could influence observed active galactic nucleus photometric variability. We present 3D hydrodynamic simulations of OJ 287, using the code PHANTOM. We simulate two mass ratios, (i) M1 = 1.835 × 1010 M⊙ with M2 = 1.4 × 108 M⊙ and (ii) M1 ≍ M2 (∼108 M⊙), along with (iii) a control of a single SMBH and accretion disk. We find that the simulation with masses 1.835 × 1010 M⊙ and 1.4 × 108 M⊙ evolves consistently with the most currently accepted model of OJ 287 as a precessing SMBH binary. The secondary's impacts with the disk result in the formation of spiral density waves and a corresponding ∼10%─20% increase in the mass accretion rate of the primary SMBH. The impact timings and the mass accretion rate spikes show quasiperiodic variability as a result of the precession of the secondary's orbit with intervals between impacts ranging from ∼1 to ∼10 yr. In the near-equal mass case, the disk of the primary becomes tidally disrupted after ∼2 yr. Consequently, the near-equal mass system with a period of 12 yr is not a viable candidate for OJ 287. This modeling provides insights into the potential signatures of SMBH binaries by both gravitational wave observatories and the Rubin Legacy Survey of Space and Time.

Keywords: Accretion, Hydrodynamical simulations, Black holes, Blazars, Gravitational wave sources, Active galactic nuclei
Evidence of Gas Depletion in Quasars with Moderate Radio Emission. The energy released by active galactic nuclei (AGNs) is considered to have a profound impact on the cold gas properties of their host galaxies, potentially heating or removing the gas and further suppressing star formation. To understand the feedback from AGN radio activity, we investigate its impacts on the cold gas reservoirs in AGNs with different radio activity levels. We construct a quasar sample with a mean z ∼ 1.5 and a mean Lbol ∼ 1045.8 erg s−1, all with Herschel detections to enable estimates of the total gas mass through the galactic dust continuum emission. The sample is then crossmatched with radio catalogs and divided into radio-loud quasars, radio-detected radio-quiet (RQ) quasars, and radio-undetected quasars based on their radio loudness. Through spectral energy distribution fitting, we find the radio-detected RQ quasars exhibit evidence of gas deficiency with host galaxies possessing ∼0.3 dex lower dust and gas masses compared to the other two groups, despite being matched in MBH, Lbol, M*, and star formation rate. Furthermore, evidence from optical spectra shows that both the fraction and velocity of outflows are higher in the radio-detected RQ group, suggesting a connection between the ionized gas outflows and the moderate radio activity. These results suggest that the AGN feedback could be more efficient in AGNs with weak/moderate radio emission than in those without radio detection or those with strong radio emission. Further high-resolution observations are needed to understand the interaction between the interstellar medium and the weak/moderate AGN radio activity.

Keywords: AGN host galaxies, Radio quiet quasars, Active galactic nuclei
Secular Excitation of Polar Neptune Orbits in Pure Disk─Planet Systems. The stellar spin─orbit angles of Neptune-sized planets present a primordial yet puzzling view of the planetary formation epoch. The striking dichotomy of aligned and perpendicular orbital configurations are suggestive of obliquity excitation through secular resonance—a process where the precession of a hot Neptune becomes locked onto a forcing frequency and is slowly guided into a perpendicular state. Previous models of resonant capture have involved the presence of companion perturbers to the star─planet─disk system, but in most cases, such companions are not confirmed to be present. In this work, we present a mechanism for exciting Neptunes to polar orbits in systems without giant perturbers, where photoevaporation is the self-contained mechanism. Photoevaporation opens a gap in the protoplanetary disk at ∼1 au, and the inner disk continues to viscously accrete onto the host star, precessing quickly due to the perturbation of the outer disk. As the inner disk shrinks, it precesses more slowly and encounters a resonance with the J2 precession of the Neptune, quickly exciting it to a polar configuration. While likely not applicable to more massive planets that trigger backreactions onto the disk, this mechanism reproduces the obliquities of small planets in multiple respects.

Keywords: Exoplanet dynamics, Protoplanetary disks
Void Galaxies and Active Galactic Nucleus Activity in ZOBOV-identified TNG300 Voids from z = 3 to z = 0. We study void galaxies in the TNG300 simulation between redshifts z = 3 and z = 0. Cosmic void catalogs were constructed using a watershed-based void-finding algorithm, and we define four populations of field galaxies for our investigation: (1) galaxies that are members of a watershed void, (2) galaxies that are located within a radius r ≤ 0.8Reff of the center of a void, (3) galaxies interior to spheres centered on void centers that have underdensity contrasts &lt;─0.8, and (4) nonvoid galaxies. We show that population statistics on void galaxy properties can be recovered from watershed-based void catalogs. Differences between galaxy populations are most pronounced interior to the shell-crossing surface (i.e., population 3), where densities are intermediate to high. Compared to nonvoid galaxies at all redshifts, the density-controlled galaxies are bluer, smaller, more actively star-forming, more massive, and less metal-enriched. At redshifts ≥1, these differences are less apparent, likely caused by resolution and selection effects incurred by attempting to define a density-controlled sample from a watershed-based void-finding algorithm. Further, we investigate the fraction of galaxies with active galactic nuclei (AGN) and find that our density-controlled population has AGN fractions that are significantly higher than those of nonvoid galaxy populations (79.8% ± 0.4% higher at z = 0.0 and 61.5% ± 0.7% higher at larger redshifts).

Keywords: Magnetohydrodynamical simulations, Voids, Galaxy evolution, Large-scale structure of the universe
Limiting Eccentricity in Restricted Hierarchical Three-body Systems with Short-range Forces. A hierarchical three-body model can be widely applied to diverse astrophysical settings, from satellite─planet─star systems to binaries around supermassive black holes. The octupole-order perturbation on the inner binary from the tertiary can induce extreme eccentricities and cause orbital flips of the binary, but short-range forces such as those due to general relativity (GR) may suppress extreme eccentricity excitations. In this paper, we consider restricted hierarchical three-body systems, where the inner binary has a test-mass component. We investigate the maximum possible eccentricity (called "limiting eccentricity") attainable by the inner binary under the influence of the tertiary perturbations and GR effect. In systems with sufficiently high hierarchy, the double averaging (DA) model is a good approximation; we show that the orbits that can flip under the octupole-order perturbation reach the same limiting eccentricity, which can be calculated analytically using the quadrupole-order Hamiltonian. In systems with moderate hierarchy, DA breaks down and the so-called Brown Hamiltonian is often introduced as a correction term; we show that this does not change the limiting eccentricity. Finally, we employ the single averaging (SA) model and find that the limiting eccentricity in the SA model is higher than the one in the DA model. We derive an analytical scaling for the modified limiting eccentricity in the SA model.

Keywords: Gravitational interaction, General relativity
A Low-mass Model of the Milky Way: The Disk Warp Resulting from a Galaxy Merger. Previous studies have shown that disk warps can result from galaxy mergers. Recent research indicates a noticeable decline in the rotation curve (RC) of the Milky Way, suggesting the need for a new low-mass model to describe its dynamical features. This study constructs a new Gaia─Sausage─Enceladus merger model to characterize the RC features of our Galaxy. We use the GIZMO code to simulate mergers with various orbital parameters to investigate how the disk warp evolves under different conditions. This simulation demonstrates the evolutionary mechanism of disk warp, which arises due to the asymmetric gravitational potential of the dark matter (DM) halo generated universally by galaxy mergers. The results indicate that the tilt angle of the DM halo partly reflects the gravitational strength at the Z = 0 plane, while the gravitational strength on the disk plane reflects the amplitude of disk warp. We identify a dual-regime interaction mechanism driven by the asymmetric halo potential. On short timescales, we find a distinct anticorrelation between the halo's tilt angle and the disk's warp amplitude, indicating a "seesaw" mechanism of angular momentum exchange. On secular timescales, however, dynamical friction drives a global alignment, causing both the halo tilt and the warp amplitude to decay simultaneously. Furthermore, we demonstrate that high-inclination mergers can sustain long-lived prograde precession, where the persistent yet decaying gravitational torque maintains the prograde bending mode against differential windup.

Keywords: Milky Way dark matter halo, Hydrodynamical simulations, Galaxy structure, Milky Way disk, Galaxy mergers
Multiband Gravitational-wave Observations of Eccentric Escaping Binary Black Holes from Globular Clusters. Stellar-mass binary black holes (sBBHs) formed in globular clusters (GCs) are promising sources for multiband gravitational-wave (GW) observations, particularly with low- and middle-frequency detectors. These sBBHs can retain detectable eccentricities when they enter the sensitivity bands of low-frequency GW observatories. We study multiband GW observations of eccentric sBBHs that escape from GC models simulated with the MOCCA code, focusing on how low- and middle-frequency detectors can constrain their eccentricities and other parameters. Using Monte Carlo simulations, we generate 10 realizations of cosmic sBBHs by combining the MOCCA sample with a cosmological model for GC formation and evolution. We then assess their detectability and the precision of parameter estimation. Our results show that LISA, Taiji, the LISA-Taiji (LT) network, and AMIGO could detect 0.8 ± 0.7, 11.6 ± 2.0, 15.4 ± 2.7, and 7.9 ± 1.3 escaping sBBHs, respectively, over 4 yr, while LT-AMIGO could detect 20.6 ± 3.0 multiband sBBHs in the same period. LT and AMIGO can measure initial eccentricities with relative errors of approximately 10−6─2 × 10−4 and 10−3─0.7, respectively. Joint LT-AMIGO observations have a similar ability to estimate eccentricities as LT alone.

Keywords: Globular star clusters, Gravitational wave detectors, Stellar mass black holes, Gravitational waves, Astrophysical black holes
How to Evaluate the Sufficiency and Complementarity of Summary Statistics for Cosmic Fields: An Information-theoretic Perspective. The advent of increasingly advanced surveys and cosmic tracers has motivated the development of new inference techniques and novel approaches to extracting information from cosmic fields. A central challenge in this endeavor is to quantify the information content carried by these summary statistics in cosmic fields. In particular, how should we assess which statistics are more informative than others and assess the exact degree of complementarity of the information from each statistic? Here, we introduce mutual information (MI), which provides, from an information-theoretic perspective, a natural framework for assessing the sufficiency and complementarity of summary statistics in cosmological data. We demonstrate how MI can be applied to typical inference tasks to make information-theoretic evaluations, using two representative examples: the cosmic microwave background map, from which the power spectrum (PS) extracts almost all information as is expected for a Gaussian random field, and the 21 cm brightness temperature map, from which the scattering transform extracts the most non-Gaussian information but which is complementary to the PS and bispectrum. Our results suggest that MI offers a robust theoretical foundation for evaluating and improving summaries, thereby enabling a deeper understanding of cosmic fields from an information-theoretic perspective.

Keywords: Cosmology, Bayesian statistics, Fisher's Information
ALMA Polarization Study of the Magnetic Fields in Two Massive Clumps in the 20 km s<SUP>−1</SUP> Cloud of the Central Molecular Zone. We present the Atacama Large Millimeter/submillimeter Array observations of linearly polarized 870 μm continuum emission at ∼0 .″ 2 (2000 au) resolutions toward the two massive clumps, Clump 1 and Clump 4, in the 20 km s−1 cloud. The derived magnetic field strength for both clumps ranges from ∼0.3 to 3.1 mG using the angular dispersion function method. The magnetic field orientations across multiple scales suggest that the magnetic field dominates at the cloud scale, whereas gravity appears to govern structures at the core (0.01−0.1 pc) and condensation (≤0.01 pc) scales. Furthermore, the study on the angular difference between the orientations of the local gravity gradient and the magnetic field suggests that the magnetic field predominantly governs the dynamics in the diffuse regions, while gravity and star formation feedback become increasingly significant within the dense regions. The ratio of the magnetic field tension force FB to the gravitational force FG suggests that the magnetic field may provide some support against gravity, but it is insufficient to prevent gas from infalling toward the dense cores.

Keywords: Interstellar magnetic fields, Galactic center, Polarimetry
Convolutional Neural Networks for Classifying Galaxy Mergers: Can Faint Tidal Features Aid in Classifying Mergers?. Identifying mergers from observational data has long been a crucial aspect of studying galaxy evolution and formation. Tidal features, typically fainter than 26  magarcsec−2 , exhibit a diverse range of appearances depending on merger characteristics and are expected to be investigated in greater detail with the Rubin Observatory Legacy Survey of Space and Time (LSST), which will reveal the low-surface-brightness Universe with unprecedented precision. Our goal is to assess the feasibility of developing a convolutional neural network (CNN) that can distinguish between mergers and nonmergers based on LSST-like deep images. To this end, we used Illustris TNG50, one of the highest-resolution cosmological hydrodynamic simulations to date, allowing us to generate LSST-like mock images with a depth ∼29  magarcsec−2  for low-redshift (z = 0.16) galaxies, with labeling based on their merger status as ground truth. We focused on 151 Milky Way─like galaxies in field environments, comprising 81 nonmergers and 70 mergers. After applying data augmentation and hyperparameter tuning, a CNN model was developed with an accuracy of 65%─67%. Through additional image processing, the model was further optimized, achieving an accuracy of 67%─70% when trained on images containing only faint features. This represents an improvement of ∼5% compared to training on images with bright features only. This suggests that faint tidal features can serve as effective indicators for distinguishing between mergers and nonmergers. Future directions for improvement motivated by this study are also discussed.

Keywords: Tidal distortion, Convolutional neural networks, Galaxy interactions, Galaxy mergers, Tidal interaction
The Orbital Parameters of Gamma-Ray Binary PSR J2032+4127. PSR J2032+4127 is the only gamma-ray binary that exhibits pulsations in gamma rays. Previous research has indicated that the pulsar and the Be star MT91 213 orbit each other in a highly eccentric orbit with an extremely long period, with the pulsar reaching its periastron on 2017 November 13. Since its launch, the Fermi satellite has been monitoring this pulsar for 16 yr, covering the 8 yr before and the 8 yr after the pulsar passed its periastron. Using these data, we present an analysis of pulse arrival times and precisely determine the orbital parameters for the first time: the orbital period of Porb ∼ 52.3 yr, the eccentricity of e ∼ 0.98, the semimajor axis of asini ∼ 25.3 au, and the orbital inclination of ∼47 .° 1─55 .° 1. We also reveal another small glitch occurred in 2021, MJD ∼ 59500.

Keywords: Gamma-ray sources, Binary stars, Rotation powered pulsars, Pulsars