Sazuna/UAT_keywords huggingface dataset:
Two Events with Spectacular Moving Structures in a Failed Solar Filament Eruption. We investigate the complex magnetic reconnection process between the filament and surrounding loops during the failed filament eruption that occurred in NOAA active region 13445 on 2023 September 24, using extreme-ultraviolet observations from the Solar Dynamics Observatory and high-resolution Hα imaging from the New Vacuum Solar Telescope. This failed filament eruption is associated with an M4.4 flare (SOL2023-09-24T03:28). At the early phase of the filament eruption, the filament displays a distinct clockwise rotational motion, suggesting an untwisting motion. During the flare precursor phase, the northwest slipping motion of the brightenings at the filament's left footpoint, along with the brightening and continuous expansion of the nearby loops at the northwest, suggest the occurrence of a slipping magnetic reconnection between the filament and peripheral loops at the quasi-separatrix layer. After the slipping motion begins, significant brightenings of filament materials and multiple bright structures moving toward the two filament footpoints are observed during the two episodes of magnetic reconnection between the filament and the overlying loops, with the most prominent brightenings and the moving structures occurring during the main phase of the M4.4 flare. The observed untwisting motion of the filament and the twist reduction derived from the nonlinear force-free field extrapolation suggest that the magnetic reconnection between the filament and the peripheral and overlying loops plays a significant role in the failure of the filament eruption by greatly reducing its twist.

Keywords: Solar active region magnetic fields, Solar atmosphere, Solar flares, Solar magnetic reconnection, Solar active region filaments, Solar physics, Solar filaments, Solar filament eruptions, Solar activity
Formation and Evolution of Compact Binaries Containing Intermediate-mass Black Holes in Dense Star Clusters. We investigate the evolution of star clusters containing intermediate-mass black holes (IMBHs) of 300─5000 M⊙, focusing on the formation and evolution of IMBH─stellar-mass black hole (MBH ≲ 102 M⊙) binaries. Dense stellar systems like globular clusters (GCs) or nuclear star clusters offer unique laboratories for studying the existence and impacts of IMBHs. IMBHs residing in GCs have been under speculation for decades, with their broad astrophysical implications for the cluster's dynamical evolution, stellar population, and gravitational-wave (GW) signatures, among others. While existing GW observatories, such as the Advanced Laser Interferometer Gravitational-wave Observatory (aLIGO), target binaries with relatively modest mass ratios, q ≲ 10, future observatories, such as the Einstein Telescope (ET) and the Laser Interferometer Space Antenna (LISA), will detect intermediate-mass ratio inspirals (IMRIs) with q &gt; 10. This work explores the potential for detecting IMRIs by adopting these upcoming telescopes. For our experiments, we perform multiple direct N-body simulations with IMBHs, utilizing Nbody6++GPU, after implementing the GW merger schemes for IMBHs. We then study the statistical properties of the resulting IMRIs, such as the event rates and orbital properties. Assuming that IMRIs with a signal-to-noise ratio &gt; 8 are detectable, we derive the following detection rates for each observatory: ≲0.02 yr−1 for aLIGO, ∼101−355 yr−1 for ET, ∼186−200 yr−1 for LISA, ∼0.24−0.34 yr−1 for aSOGRO, and ∼3880−4890 yr−1 for DECIGO. Our result confirms the capability of detecting IMRIs with future GW telescopes.

Keywords: Intermediate-mass black holes, General relativity, Gravitational waves, Star clusters
On the Extended Soft X-Ray and Fe Kα Emission in NGC 1068. The soft X-ray excess and Fe Kα emission lines are widely observed in Seyfert galaxies, with their origin still in debate. We present a detailed spatially resolved image and spectral analysis of the Seyfert 2 galaxy NGC 1068 using high-resolution Chandra ACIS data. We find that the soft X-ray emission and iron emission show extended structures in the northeast and southwest directions. Especially, the soft X-ray extends predominantly in the 1″‑15″ (∼72 pc–1 kpc) northeast sector with a distance of at least ∼10″ (∼700 pc), and its 0.5–3.0 keV flux is about ∼2/3 of that from the 1″ radius circular region centered on the core of NGC 1068. We fit the soft X-ray spectra from the core and two bright blobs (∼3″, S1 and ∼1 .″ 5, S2 from the nucleus) as a dual-temperature plasma with two APEC models. Our analysis suggests that the extended soft X-ray emission in NGC 1068, as well as contributions to Fe Kα emission from the extended region, likely originate from the interactions between the jet and the interstellar medium, offering further insights into the origin of soft X-ray excess and Fe Kα emission lines in similar Seyfert sources. However, extended X-ray emission outside the ionization cone might be influenced by additional processes; future multiwavelength observations will be needed to test these possibilities.

Keywords: Seyfert galaxies, Active galactic nuclei, X-ray active galactic nuclei
Low Accretion Rates in Black Holes in Late-stage Merger Ultraluminous Infrared Galaxies. We explore the accretion rates of supermassive black holes (SMBHs) in late-stage galaxy mergers by observing three ultraluminous infrared galaxies (ULIRGs), IRAS 14378-3651, IRAS 17208-0014 and IRAS 23365+3604, using the JWST/MIRI Medium Resolution Spectrometer and JWST/NIRSpec integral field unit. In all three cases, we fail to detect [Ne VI] λ7.65 μm, a robust active galactic nuclei (AGN) tracer lying in a low-opacity interstellar window, nor do we detect any other lines that might indicate AGNs. The only detected high-excitation emission line, [Mg IV] (λ4.488 μm), arises from shocks associated with supernovae. Our new, deep flux limits on AGN tracers in the near- and mid-infrared indicate that the nuclear obscuration of any purported AGNs in our sample is isotropic, i.e., the far-infrared luminosities of these galaxies are unlikely to be driven by escaping AGN power. This allows us to show that the Eddington ratios of their SMBHs are low. We then assemble an unbiased sample of 19 ULIRGs (from the IRAS Bright Galaxy Sample with L(TIR) ≥ 1012 L⊙) in late-stage mergers and show that their dynamically measured black hole masses are consistent with the values from scaling from their stellar masses. On this basis, we show that the Eddington ratios of any AGNs in 15 of these galaxies are also very low, ≲10%. This indicates that any black holes are in a relatively quiescent state. That is, high levels of accretion are found in only a minority of late-merger-phase ULIRGs.

Keywords: Ultraluminous infrared galaxies
3D Magnetohydrodynamic Wave Propagation and Energy Transport in a Simulated Solar Vortex. Magnetic flux tubes in the presence of background rotational flows are abundant throughout the solar atmosphere and may act as conduits for MHD waves to transport energy throughout the solar atmosphere. Here we investigate the contribution from MHD waves to the Poynting flux in a 3D numerical simulation of a realistic solar atmosphere, modeling a structure resembling a solar vortex tube, using the PLUTO code in the presence of different plasma flow configurations. These simulations feature a closed magnetic loop system where a rotational flow is imposed at one footpoint in addition to photospheric perturbations acting as a wave driver mimicking those of p-modes. We find that a variety of MHD waves exist within the vortex tube, including sausage, kink, and torsional Alfvén waves, owing to the photospheric wave driver and the nature of the rotational flow itself. We demonstrate how the visual interpretation of different MHD modes becomes nontrivial when a background rotational flow is present compared to a static flux tube. By conducting a simulation both with and without the rotational plasma flow, we demonstrate how the perturbed Poynting flux increases in the presence of the rotational flow as the waves transport increased magnetic energy. We attribute this increase to the dynamical pressure from the rotational flow increasing the plasma density at the tube boundary, which acts to trap the wave energy more effectively inside the vortex. Moreover, we demonstrate how the Poynting flux is always directed upward in weakly twisted magnetic flux tubes.

Keywords: Solar oscillations, Solar atmosphere, Magnetohydrodynamics, Solar chromosphere
Detection of [O III]<SUB>88 μm</SUB> in JADES-GS-z14-0 at z = 14.1793. We report the first successful Atacama Large Millimeter/submillimeter Array (ALMA) follow-up observations of a secure z &gt; 10 JWST-selected galaxy, by robustly detecting (6.6σ) the [O III]88 μm line in JADES-GS-z14-0 (hereafter GS-z14). The ALMA detection yields a spectroscopic redshift of z = 14.1793 ± 0.0007, and increases the precision on the prior redshift measurement of  z=14.32−0.20+0.08  from NIRSpec by ≳180×. Moreover, the redshift is consistent with that previously determined from a tentative detection (3.6σ) of C III]1907,1909 (z = 14.178 ± 0.013), solidifying the redshift determination via multiple line detections. We measure a line luminosity of L[O III]88 = (2.1 ± 0.5) × 108 L⊙, placing GS-z14 at the lower end, but within the scatter of, the local L[O III]88─star formation rate relation. No dust continuum from GS-z14 is detected, suggesting an upper limit on the dust-to-stellar mass ratio of &lt;2 × 10−3, consistent with dust production from supernovae with a yield yd &lt; 0.3 M⊙. Combining a previous JWST/MIRI photometric measurement of the [O III]λλ4959,5007 Å and Hβ lines with CLOUDY models, we find GS-z14 to be surprisingly metal-enriched (Z ∼ 0.05─0.2 Z⊙) a mere 300 Myr after the Big Bang. The detection of a bright oxygen line in GS-z14 thus reinforces the notion that galaxies in the early Universe undergo rapid evolution.

Keywords: Early universe, High-redshift galaxies, Galaxy evolution, Interstellar medium
Convection Anisotropies of Cosmic Rays in Highly Magnetized Plasma. Recently, Y. Zhang &amp; S. Liu proposed a turbulent convection model for multiscale anisotropies of cosmic rays (CRs), with an assumption of isotropic diffusion such that the anisotropies are statistically isotropic. However, this assumption may be unrealistic for TeV CRs, whose observations have revealed the significance of the local interstellar background magnetic field. To meet the difficulty, the turbulent convection scenario needs to be extended to cover anisotropic diffusion. In this paper, we focus on the parallel diffusion with isotropic pitch-angle scattering, which may be an approximation to the transport process driven by weak hydromagnetic waves in a magnetic flux tube, where fluctuations of the wave velocities lead to the turbulent convection. The consequence is the breaking of the statistical isotropy, while the overall shape of the angular power spectrum,  Cℓ¯∝ℓ‑γ‑1  (ℓ ≫ 1), remains similar to that in the isotropic diffusion model, where ℓ is degrees of spherical harmonics and γ is the turbulence spectral index of the convection field. It is then expected that the power-law index of the TeV CR small-scale angular power spectrum can be explained with the Kolmogorov law γ = 5/3, irrespective of the background magnetic field to some extent.

Keywords: Interstellar dynamics, High energy astrophysics, Cosmic ray astronomy, Interstellar plasma, Galactic cosmic rays, Interstellar medium, Particle astrophysics, Cosmic rays
Searching for Radio Pulsars in Old Open Clusters from the Parkes Archive. Motivated by the discovery of a pulsar in the direction of the old open cluster NGC 6791, we conducted a search for radio pulsars in archival Parkes observations targeting similar old open clusters. We reprocessed 224 observations totalling 75.02 hr from four clusters: Theia 1661, NGC 6259, Pismis 3, and Trumpler 20. Our analysis identified five known pulsars and three new rotating radio transient (RRAT) candidates. By comparing the measured dispersion measures (DMs) with the expected DM values for each cluster derived from YMW16 and NE2001 models, we conclude that most detected sources are likely background pulsars. However, RRAT J1749‑25 in Theia 1661 and RRAT J1237‑60 in Trumpler 20 have DMs reasonably close to their respective clusters, suggesting possible membership. The association between PSR J1750‑2536 and Theia 1661 remains ambiguous due to its intermediate DM. These candidate cluster-associated neutron stars warrant follow-up with more sensitive telescopes such as MeerKAT or the Square Kilometre Array, potentially offering valuable insights into neutron star retention mechanisms and evolution in open cluster environments.

Keywords: Open star clusters, Radio bursts, Radio pulsars
Correlation Between U/Th and Pb/Os Abundance Ratios and its Application in Nuclear Cosmochronology. The abundance ratios of radioactive elements U/Th and stable elements Pb/Os from the r-process are found to have a strong correlation. This correlation is quite robust with respect to astrophysical conditions. The U/Th–Pb/Os correlation is applied to provide customized initial abundance ratios U/Th from the observed abundance ratios Pb/Os for six r-process enhanced metal-poor stars. The ages of these six metal-poor stars are predicted by the U/Th chronometer, which are approximately between 11 and 15 Gyr. Their ages are compatible with the cosmic age of 13.8 billion years predicted from the cosmic microwave background radiation.

Keywords: Nuclear abundances, Nuclear astrophysics, Stellar ages, R-process
BatAnalysis—A Comprehensive Python Pipeline for Swift BAT Time-tagged Event Data Analysis. The Neil Gehrels Swift Observatory (Swift) Burst Alert Telescope (BAT) is a coded aperture gamma-ray instrument with a large field of view that was designed to detect and localize transient events. When a transient is detected, either on board or externally, the BAT saves time-tagged event (TTE) data, which provide the highest-quality information of the locations of the photons on the detector plane and their energies. These data can be used to produce spectra, lightcurves, and sky images of a transient event. While these data products are produced by the Swift Data Center and can be produced by current software, they are often preset to certain time and energy intervals, which have limited their use in the current time domain and multimessenger environment. Here, we introduce a new capability for the BatAnalysis Python package to download and process TTE data under an open-source Python framework that allows for easy interfacing with other Python packages. The new capabilities of the BatAnalysis software allow for TTE data to be used by the community in a variety of advanced customized analyses of astrophysical sources which BAT may have TTE data for, such as fast radio bursts (FRBs), gamma-ray bursts (GRBs), low-mass X-ray binaries (LMXB), soft gamma repeaters, magnetars, and many other sources. We highlight the usefulness of the BatAnalysis package in analyzing TTE data produced by an onboard GRB trigger, an FRB external trigger, a subthreshold detection of the LMXB EXO 0748–676, and an external trigger of a GRB that BAT detected during a slew.

Keywords: High energy astrophysics, Open source software, Astronomy data analysis, Astronomy data acquisition
The Onset of Feedback in A1885: Evidence for Large-scale Quenching Despite a Young Central Active Galactic Nucleus. We present a new 8.5 ks Chandra observation of A1885 (z = 0.089), obtained as part of the Cluster Evolution Reference Ensemble At Low-z (CEREAL) survey of ∼200 low-z galaxy groups and clusters. These data reveal that A1885 is a strong cool core, with a central cooling time of  0.43−0.04+0.12  Gyr, and that the central galaxy hosts an X-ray-luminous point source at its center (L 2−10keV=2.3−0.7+0.9×1042  erg s−1), indicative of a rapidly accreting supermassive black hole (SMBH). In the context of the larger CEREAL sample, we constrain the fraction of clusters at z ∼ 0.15 with X-ray-bright (L2−10 &gt; 1042 erg s−1) central active galactic nuclei (AGN) to be no more than 4.1% at 95% confidence. Including radio data from LOFAR, the Giant Metrewave Radio Telescope, ASKAP, and the Very Large Array, spanning 44 MHz─150 GHz, and optical integral field unit data from the Sloan Digital Sky Survey's MaNGA, we probe the details of cooling, feeding, and feedback in this system. These data reveal that cooling of the intracluster medium is highly suppressed on large (&gt;10 kpc) scales despite a central SMBH that is in the early stages of the self-regulation cycle (characterized by rapid accretion, physically small jets, and no large-scale low-frequency radio emission). To reconcile the large-scale quenching with a lack of visible large-scale feedback, we propose that the timescale on which energy is dissipated on large scales (&gt;10 kpc) is significantly longer than the timescale on which black hole feeding operates on small (∼parsec) scales. This interpretation disfavors a model in which the energy is rapidly dissipated (e.g., shocks), which would synchronize the feeding and feedback timescales, and favors a model in which the heating effects of AGN feedback can linger long after the outburst has passed (e.g., turbulent mixing).

Keywords: Galaxy clusters, Intracluster medium, Active galactic nuclei, X-ray astronomy
Changing-look Active Galactic Nuclei: A Study of Optical/UV and the Highly Ionized Fe Kα X-Ray Line Flux Variations Using Photoionization Simulations. Significant variability in broad emission line strengths of active galactic nuclei (AGN) over months to years has been observed, often accompanied by intrinsic continuum changes. Such spectral variability challenges the traditional AGN classification scheme, which attributes differences between type 1 and type 2 to geometrical effects, as transitions between these types occur on timescales shorter than viscous ones. In this work, using the cloudy photoionization simulations, we investigated the response of the major emission line fluxes, in the optical/UV and hard X-ray bands, to changes in the intensity and shape of the continuum emission of the AGN under two scenarios: (i) changes in the X-ray power law while keeping disk emission fixed, and (ii) broadband continuum variations. We demonstrate that broad-line region (BLR) line fluxes are insensitive to X-ray power-law changes alone. Considering a well-studied case of the changing-look (CL) AGN Mrk 1018, which exhibits variations in the intrinsic disk emission, as well as the X-ray power law, our simulations reproduce observed brightening and dimming trends of the BLR emission. Moreover, we show that the highly ionized Fe Kα X-ray flux, primarily produced by the H-like and He-like ions of Fe, strongly depends on the X-ray strength of the intrinsic spectral energy distribution. These findings suggest that the origin of highly ionized Fe Kα emission is in the coronal part of the accretion disk and that the CL phenomenon can be triggered by intrinsic changes in the accretion properties of AGN.

Keywords: Photoionization, Quasars, Seyfert galaxies, Active galactic nuclei, X-ray active galactic nuclei
In Search of the First Stars: An Ultra-compact and Very-low-metallicity Lyα Emitter Deep within the Epoch of Reionization. We present JWST observations of a gravitationally lensed, extremely metal-poor galaxy at redshift z = 8.203 ± 0.001 from the CANUCS survey. Based on the low oxygen to Balmer line ratios, we infer a gas-phase metallicity of 12 + log(O/H) = 6.85 (1.4% solar), making CANUCS-A370-z8-LAE one of the most metal-poor galaxies known at z &gt; 7. The galaxy has a high Hβ equivalent width of 225 ± 50 Å, small half-light radius of only  rhl=38‑19+3  pc, and high star formation rate density of 50–100 M⊙ yr‑1 kpc‑2. The galaxy shows high-equivalent-width Lyα emission with an inferred Lyα escape fraction of 0.21 ± 0.05. The high escape fraction of Lyα is likely due to the compact starbursting nature of the galaxy combined with its location in an overdensity traced by at least two other galaxies spectroscopically confirmed to lie within δz = 0.01 that have helped to reionize the environment. The low metallicity of CANUCS-A370-z8-LAE is best explained by a model where infalling metal-poor gas dilutes the interstellar medium, rather than being a young galaxy forming its first stellar populations.

Keywords: Emission line galaxies, Galaxy evolution, Lyman-alpha galaxies, Reionization, Metallicity
Exploring Quasar Variability with ZTF at 0 &lt; z &lt; 3: A Universal Relation with the Eddington Ratio. Quasars, powered by accretion onto supermassive black holes (SMBHs), exhibit significant variability, offering insights into the physics of accretion and the properties of the central engines. In this study, we analyze photometric variability and its correlation with key quasar properties, including black hole mass (MBH) and nuclear luminosities, using 915 quasars with 0 ≤ z &lt; 3.0 from the All Quasar Multi-Epoch Spectroscopy sample monitored within the fifth-generation Sloan Digital Sky Survey (SDSS-V). Variability metrics were derived from approximately 6 yr light curves provided by the Zwicky Transient Facility (ZTF), while SMBH masses and luminosities were obtained from the SDSS DR16 quasar catalog of Q. Wu &amp; Y. Shen. We identify a strong anticorrelation between variability amplitude and luminosity, which strengthens with redshift, and a redshift-dependent trend for MBH: a positive correlation at low redshifts, no significant correlation at intermediate redshifts, and an anticorrelation at the highest redshifts. Our main finding is a robust anticorrelation between photometric variability amplitude and Eddington ratio, consistent across different redshift bins. We present a general equation encapsulating this relationship, which appears to be almost free of redshift dependence, enabling predictions of quasar variability based on accretion parameters or vice versa. The derived relation with the Eddington ratio provides a unified framework for interpreting variability in active galactic nuclei and facilitates future studies of quasar variability using high-cadence surveys, such as the Vera C. Rubin Observatory's Legacy Survey of Space and Time.

Keywords: Supermassive black holes, Quasars, Radio quiet quasars, Active galactic nuclei, Broad band photometry, Catalogs
MWA and VLA Observations of Diffuse Radio Lobes in M87. This study investigates the projected, quasi-symmetric ∼46 kiloparsec-scale diffuse radio lobes surrounding the giant elliptical galaxy M87, utilizing well-sampled wideband (60 MHz–10.55 GHz) observations from the Murchison Widefield Array and Very Large Array, supplemented by data from the Low-frequency Array and Effelsberg. The observed structures feature sharp edges and filaments, with nearly uniform and moderately steep spectral indices (α, mostly within ‑1.2 ≤ α ≤ ‑0.8), indicating turbulence. Well-sampled radio spectra for the lobes' diffuse region are derived using the continuous injection (CI) model (with αinj ≃ ‑0.86 and νb ≃ 1.72 GHz), and for its three localized regions using the impulsive injection model (e.g., the Jaffe–Perola (JP) model). From energy equipartition analysis, we estimate the typical magnetic field strength in the lobes' diffuse region to be Beq ≃ 10 μG. The age of the lobes is estimated as ∼30–50 Myr, based on lifetimes derived from the CI and JP models and sound crossing time. Outflow powers of ∼(0.2–2) × 1044 erg s–1 for the lobes' diffuse components and ∼(1–11) × 1044 erg s–1 for the whole source are calculated. With this power assessment, we conclude that the galactic stellar wind has a negligible effect, and the active galactic nucleus (AGN)-driven jet can provide the necessary energy for the whole system. Furthermore, we argue that while the wind driven by current AGN activity is unlikely to power the lobes' diffuse components, an average enhancement of AGN activity by a factor of ∼102 over the past ∼30–50 Myr remains plausible.

Keywords: Active galaxies, Radio lobes, Radio active galactic nuclei, Radio continuum emission, Radio interferometry