Sazuna/UAT_keywords huggingface dataset:
The Radio Halo in PLCKESZ G171.94–40.65: Beacon of Merging Activity. We present the first multifrequency analysis of the candidate ultrasteep spectrum radio halo in the galaxy cluster PLCKESZ G171.94‑40.65, using the upgraded Giant Metrewave Radio telescope (400 MHz), and Karl G. Jansky Very Large Array (1–2 GHz) observations. Our radio data have been complemented with archival Chandra X-ray observations to provide a crucial insight into the complex intracluster medium physics, happening at large scales. We detect the radio halo emission to the extent of ∼1.5 Mpc at 400 MHz, significantly larger than previously reported, along with five tailed galaxies in the central region. We also report the discovery of an unknown diffuse source "U," at the cluster periphery, with an extent of 300 kpc. Using the available observations, we have found that the radio spectrum of the halo is well-fitted with a single power law, having a spectral index of ‑1.36 ± 0.05, indicating that it is not an ultrasteep spectrum radio halo. Our low-resolution (25″) resolved spectral map shows an overall uniform spectral index, with some patches of fluctuations. The X-ray and radio surface brightness are morphologically cospatial, with a slight extension along the northwest–southeast direction, seen in both maps. The radio and X-ray surface brightness indicates strong positive correlations, with sublinear correlation slopes (∼0.71). Multiple tailed galaxies and the radio halo indicate a high dynamical activity at the cluster central region.

Keywords: Galaxy clusters, Extragalactic radio sources, Intracluster medium, Radio continuum emission
Density Fluctuations in the Intracluster Medium: An Attempt to Constrain Viscosity with Cosmological Simulations. The impact of viscosity in the intracluster medium (ICM) is still an open question in astrophysics. To address this problem, we have run a set of cosmological simulations of three galaxy clusters with a mass larger than M Vir &gt; 1015 M ⊙ at z = 0 using the smoothed particle magnetohydrodynamics-code OPENGADGET3. We aim to quantify the influence of viscosity and constrain its value in the ICM. Our results show significant morphological differences at small scales, temperature variations, and density fluctuations induced by viscosity. We observe a suppression of instabilities at small scales, resulting in a more filamentary structure and a larger amount of small structures due to the lack of mixing with the medium. The conversion of kinetic to internal energy leads to an increase of the virial temperature of the cluster of ∼5%–10%, while the denser regions remain cold. The amplitude of density and velocity fluctuations are found to increase with viscosity. However, comparison with observational data indicates that the simulations, regardless of the viscosity, match the observed slope of the amplitude of density fluctuations, challenging the direct constraint of viscosity solely through density fluctuations. Furthermore, the ratio of density to velocity fluctuations remains close to 1 regardless of the amount of viscosity, in agreement with the theoretical expectations. Our results show for the first time in a cosmological simulation of a galaxy cluster the effect of viscosity in the ICM, a study that is currently missing in the literature.

Keywords: Galaxy clusters, Computational methods, Intracluster medium, Magnetohydrodynamical simulations
A Modified Initial Mass Function of the First Stars with Explodability Theory under Different Enrichment Scenarios. The most metal-poor stars record the earliest metal enrichment triggered by Population III stars. By comparing observed abundance patterns with theoretical yields of metal-free stars, physical properties of their first star progenitors can be inferred, including zero-age main-sequence mass and explosion energy. In this work, the initial mass distribution of the first stars is obtained from the largest analysis to date of 406 very metal-poor stars with the newest LAMOST/Subaru high-resolution spectroscopic observations. However, the mass distribution fails to be consistent with the Salpeter initial mass function, which is also reported by previous studies. Here, we modify the standard power-law function with explodability theory. The mass distribution of Population III stars could be well explained by ensuring that the initial metal enrichment originates from successful supernova explosions. Based on the modified power-law function, we suggest an extremely top-heavy or nearly flat initial mass function with a large exponent for the explosion energy. This indicates that supernova explodability should be considered in the earliest metal enrichment process in the Universe.

Keywords: Initial mass function, Population III stars, Chemical abundances
Multiwavelength Study of Extreme High-energy Peaked BL Lac Source 1ES 0229+200 Using Ultraviolet, X-Ray, and γ-Ray Observations. We present a comprehensive analysis of the broadband spectral energy distribution (SED) of the extreme high-energy peaked BL Lac source, 1ES 0229+200. Our study utilizes near-simultaneous data collected at various epochs between 2017 September and 2021 August (MJD 58119‑59365) from different instruments, including AstroSat‑UVIT, Soft X-ray focusing Telescope, LAXPC, Swift‑UVOT, Fermi-LAT, and MAGIC. We investigate the one-zone synchrotron and synchrotron self-Compton (SSC) model, employing diverse particle distributions such as the log parabola, broken power law, power law with a maximum electron energy γ, energy-dependent diffusion (EDD), and energy-dependent acceleration (EDA) models to fit the broadband SED of the source. Our findings indicate that both peaks in the SED are well described by the one-zone SSC model across all particle distribution models. We estimate the jet power for different particle distributions. The estimated jet power for broken power law particle distributions is found to be on the order of 1047 (1044) erg s‑1 for a minimum electron energy  γmin  ∼10 (104). However, for intrinsically curved particle energy distributions (e.g., log parabola, EDD, and EDA models), the estimated jet power is ∼1044 erg s‑1. The SED fitting at five epochs enables us to explore the correlation between the derived spectral parameters of various particle distribution models. Notably, the observed correlations are inconsistent with the predictions in the power-law with a maximum γ model, although the EDD and EDA models yield the correlations as expected. Moreover, the estimated physical parameter values are consistent with the model assumptions.

Keywords: Blazars, Active galaxies, BL Lacertae objects
The ALMA-CRISTAL Survey: Spatially Resolved Star Formation Activity and Dust Content in 4 &lt; z &lt; 6 Star-forming Galaxies. Using a combination of Hubble Space Telescope (HST), JWST, and Atacama Large Millimeter/submillimeter Array (ALMA) data, we perform spatially resolved spectral energy distributions (SED) fitting of fourteen 4 &lt; z &lt; 6 ultraviolet (UV)-selected main-sequence galaxies targeted by the ALMA Large Program [C II] Resolved ISM in Star-forming Galaxies. We consistently model the emission from stars and dust in ∼0.5─1 kpc spatial bins to obtain maps of their physical properties. We find no offsets between the stellar masses (M *) and star formation rates (SFRs) derived from their global emission and those from adding up the values in our spatial bins, suggesting there is no bias of outshining by young stars on the derived global properties. We show that ALMA observations are important to derive robust parameter maps because they reduce the uncertainties in L dust (hence, AV and SFR). Using these maps, we explore the resolved star-forming main sequence for z ∼ 5 galaxies, finding that this relation persists in typical star-forming galaxies in the early Universe. We find less obscured star formation where the M * (and SFR) surface densities are highest, typically in the central regions, contrary to the global relation between these parameters. We speculate this could be caused by feedback driving gas and dust out of these regions. However, more observations of IR luminosities with ALMA are needed to verify this. Finally, we test empirical SFR prescriptions based on the UV+IR and [C II] line luminosity, finding they work well at the scales probed (approximately kiloparsec). Our work demonstrates the usefulness of joint HST-, JWST-, and ALMA-resolved SED modeling analyses at high redshift.

Keywords: Galaxy stellar content, Star formation, Galaxy evolution, Interstellar medium, High-redshift galaxies, Galaxies
Optical and Radio Analysis of Systematically Classified Broad-lined Type Ic Supernovae from the Zwicky Transient Facility. We study a magnitude-limited sample of 36 broad-lined type Ic supernovae (SNe Ic-BL) from the Zwicky Transient Facility Bright Transient Survey (detected between 2018 March and 2021 August), which is the largest systematic study of SNe Ic-BL done in literature thus far. We present the light curves (LCs) for each of the SNe and analyze the shape of the LCs to derive empirical parameters, along with the explosion epochs for every event. The sample has an average absolute peak magnitude in the r band of  M̄r,max=−18.51±0.15  mag. Using spectra obtained around peak light, we compute expansion velocities from the Fe II 5169 Å line for each event with high enough signal-to-noise ratio spectra, and find an average value of  vph̄=16,100±1100  km s−1. We also compute bolometric LCs, study the blackbody temperature and radii evolution over time, and derive the explosion properties of the SNe. The explosion properties of the sample have average values of  M̄Ni=0.37−0.06+0.08M⊙ ,  M̄ej=2.45−0.41+0.47M⊙ , and  ĒK=(4.02−1.00+1.37)×1051  erg. Thirteen events have radio observations from the Very Large Array, with eight detections and five non-detections. We find that the populations that have radio detections and radio non-detections are indistinct from one another with respect to their optically inferred explosion properties, and there are no statistically significant correlations present between the events' radio luminosities and optically inferred explosion properties. This provides evidence that the explosion properties derived from optical data alone cannot give inferences about the radio properties of SNe Ic-BL and likely their relativistic jet formation mechanisms.

Keywords: Type Ic supernovae, Relativistic jets
Widespread Rapid Quenching at Cosmic Noon Revealed by JWST Deep Spectroscopy. Massive quiescent galaxies in the young Universe are expected to be quenched rapidly, but it is unclear whether they all experience starbursts before quenching and what physical mechanism drives rapid quenching. We study 14 massive quiescent galaxies ( log(M⋆/M⊙)&gt;10 ) at z ∼ 2 selected from a representative sample of the Blue Jay survey. We reconstruct their star formation histories (SFHs) by fitting spectral energy distribution models to the JWST/NIRSpec R ∼ 1000 spectra. We find that massive quiescent galaxies can be split into three categories with roughly equal numbers of galaxies according to their SFHs: (1) relatively old galaxies quenched at early epochs; (2) galaxies that are rapidly and recently quenched after a flat or bursty formation history (depending on the assumed prior); and (3) galaxies that are rapidly and recently quenched after a major starburst. Most recently quenched galaxies show neutral gas outflows, probed by blueshifted Na I D absorption, and ionized gas emission, with line ratios consistent with active galactic nucleus (AGN) diagnostics. This suggests that AGN activity drives multiphase gas outflows, leading to rapid quenching. By tracing back the SFHs of the entire sample, we predict the number density of massive quiescent galaxies at z = 4–6: n = (1.5–6.0) × 10‑5 Mpc‑3. The two old massive quiescent galaxies in our sample appear to have extremely early formation and quenching (z ≳ 6) and are possibly descendants of early post-starbursts at z &gt; 3. These galaxies still show neutral gas reservoirs and weak Hα emission, perhaps because the ejective AGN feedback that caused rapid quenching has weakened over time.

Keywords: Galaxy quenching, Galaxy formation, Galaxy evolution, Galaxies
Using Polar Faculae to Determine the Sun's High-latitude Rotation Rate. I. Techniques and Initial Measurements. This paper describes a new way of determining the high-latitude solar rotation rate statistically from simultaneous observations of many polar faculae. In this experiment, I extracted frames from a movie made previously from flat-fielded images obtained in the 6767 Å continuum during 1997–1998 February and used those frames to construct spacetime maps from high-latitude slices of the favorably oriented south polar cap. These maps show an array of slanted tracks whose average slope indicates the east–west speed of faculae at that latitude, λ  s . When the slopes are measured and plotted as a function of latitude, they show relatively little scatter ∼ 0.01–02 km s‑1 from a straight line whose zero-speed extension passes through the Sun's south pole. This means that the speed, v(λ  s ), and the latitudinal radius,  R⊙cosλs , approach 0 at the same rate, so that their ratio gives a nearly constant synodic rotation rate ∼8.°6 day‑1 surrounding the Sun's south pole. A few measurements of the unfavorably oriented north polar cap are consistent with these measurements near the south pole.

Keywords: Solar faculae, Solar magnetic fields, Solar rotation, Solar cycle
Evidence for Abiotic Dimethyl Sulfide in Cometary Matter. Technological progress related to astronomical observatories such as the recently launched James Webb Space Telescope (JWST) allows searching for signs of life beyond our solar system, namely, in the form of unambiguous biosignature gases in exoplanetary atmospheres. The tentative assignment of a 1σ–2.4σ spectral feature observed with JWST in the atmosphere of exoplanet K2-18b to the biosignature gas dimethyl sulfide (DMS; sum formula C2H6S) raised hopes that, although controversial, a second genesis had been found. Terrestrial atmospheric DMS is exclusively stemming from marine biological activity, and no natural abiotic source has been identified—neither on Earth nor in space. Therefore, DMS is considered a robust biosignature. Since comets possess a pristine inventory of complex organic molecules of abiotic origin, we have searched high-resolution mass spectra collected at comet 67P/Churyumov–Gerasimenko, target of the European Space Agency's Rosetta mission, for the signatures of DMS. Previous work reported the presence of a C2H6S signal when the comet was near its equinox, but distinction of DMS from its structural isomer ethanethiol remained elusive. Here we reassess these and evaluate additional data. Based on differences in the electron ionization-induced fragmentation pattern of the two isomers, we show that DMS is significantly better compatible with the observations. Deviations between expected and observed signal intensities for DMS are &lt;1σ, while for ethanethiol they are 2σ–4σ. The local abundance of DMS relative to methanol deduced from these data is (0.13 ± 0.04)%. Our results provide the first evidence for the existence of an abiotic synthetic pathway to DMS in pristine cometary matter and hence motivate more detailed studies of the sulfur chemistry in such matter and its analogs. Future studies need to investigate whether or not the present inference of cometary DMS could provide an abiotic source of DMS in a planetary atmosphere.

Keywords: Biosignatures, Mass spectrometry, Comet volatiles
First Results from the Dragonfly Ultrawide Survey: The Largest 11 Quenched Diffuse Dwarf Galaxies in 3100 deg<SUP>2</SUP> with Spectroscopic Confirmation. The Dragonfly Telephoto Array employs a unique design to detect very large and diffuse galaxies that might be missed with conventional telescopes. The Dragonfly Ultrawide Survey (DFUWS) is a new wide-field survey that will cover 10,000 deg2 of the northern sky, and it provides an ideal data set to find these large diffuse galaxies. From 3100 deg2 of DFUWS data, we identified 11 large, low surface brightness galaxies as a pilot sample for spectroscopic follow-up. These are the largest galaxies in the examined area that appear smooth and isolated, with effective radii of 12″–27″. Eight are below 24  magarcsec‑2  in central g-band surface brightness. Keck Cosmic Web Imager spectra of the diffuse light show that all 11 galaxies in this sample are quiescent, and seven qualify as ultradiffuse galaxies (UDGs). Eight galaxies have distances between 15 and 30 Mpc, while the other three are in the Pegasus cluster at 50 Mpc. Their spectra show evidence of a ∼1 Gyr old stellar population in addition to an even older stellar population. The intermediate-age component is present in group and satellite galaxies but not in the Pegasus cluster UDGs. All galaxies in this sample are detected in both Dragonfly and Legacy imaging, and the sample partially overlaps with existing UDG catalogs. This pilot sample provides an excellent training set for our analysis of the upcoming full 10,000 deg2 DFUWS data, from which we may expect to discover even larger, previously unknown galaxies.

Keywords: Sky surveys, Galaxy environments, Galaxy radial velocities, Galaxy photometry, Low surface brightness galaxies
Investigating the Kinematics of Central and Satellite Galaxies Using Normalizing Flows. Galaxy clustering contains information on cosmology, galaxy evolution, and the relationship between galaxies and their dark matter hosts. On small scales, the detailed kinematics of galaxies within their host halos determines the galaxy clustering. In this paper, we investigate the dependence of the central and satellite galaxy kinematics on θ , the intrinsic host halo properties (mass, spin, concentration), cosmology (Ωm, σ 8), and baryonic feedback from active galactic nuclei and supernovae (A AGN1, A AGN2, A SN1, A SN2). We utilize 2000 hydrodynamic simulations in CAMELS run using IllustrisTNG and SIMBA galaxy formation models. Focusing on central and satellite galaxies with M * &gt; 109 M ⊙, we apply neural density estimation (NDE) with normalizing flows to estimate their p(Δr ∣ θ ) and p(Δv ∣ θ ), where Δr and Δv are the magnitudes of the halocentric spatial and velocity offsets. With NDE, we accurately capture the dependence of galaxy kinematics on each component of θ . For central galaxies, we identify significant spatial and velocity biases dependent on halo mass, concentration, and spin. For satellite distributions, we find significant deviations from a Navarro–Frenk–White profile and evidence that they consist of distinct orbiting and infalling populations. However, we find no strong dependence on θ besides a weak dependence on host halo spin. For both central and satellite galaxies, there is no notable dependence on cosmological parameters and baryonic feedback. These results provide key insights for improving the current halo occupation distribution (HOD) models. This work is the first in a series that will reexamine and develop HOD frameworks for improved modeling of galaxy clustering at smaller scales.

Keywords: Cosmology, Galaxy dark matter halos, Galaxies, Large-scale structure of the universe
Instability in Supernova Fallback Disks and Its Effect on the Formation of Ultralong Period Pulsars. Several pulsars with unusually long periods were discovered recently, comprising a potential population of ultralong period pulsars (ULPPs). The origin of their long periodicity is not well understood, but may be related to magnetars spun down by surrounding fallback disks. While there are few systematic investigations on the fallback-disk-assisted evolution of magnetars, instability in the disk has received little attention, which determines the lifetime of the disk. In this work we simulate the evolution of the magnetic field, spin period, and magnetic inclination angle of magnetars with a supernova fallback disk. We find that a thermal viscous instability in the disk could significantly affect the formation of ULPPs. Our simulation results also reveal that a large fraction of ULPPs seem to be nearly aligned and orthogonal rotators. This might help place ULPPs above the death line in the pulse period–period derivative plane. However, some extra mechanisms seem to be required to account for the radio emission of ULPPs.

Keywords: Neutron stars, Pulsars
The Study of Jet Formation Mechanism in Fermi Blazars. The origin of jet launching mainly comes from two mechanisms: the Blandford–Znajek (BZ) mechanism and the Blandford–Payne (BP) mechanism. However, it is in debate which one is dominating in blazars. In this work, we used a sample of 937 Fermi blazars to study the jet formation mechanism. We studied the correlation between the jet power and the accretion rate, as well as the comparison between jet power estimated by spectral energy distribution (SED) fitting and that estimated by theoretical formula and radio flux density. Our results suggest that there is no correlation between jet power estimated by SED fitting and the accretion rate for BL Lacertaes (BL Lacs), while a positive and weak correlation exists for flat spectrum radio quasars (FSRQs). Meanwhile, to confirm whether the BP and BZ mechanism is sufficient to launch the jet for FSRQs and BL Lacs, we compare the theoretical jet power with that estimated by SED fitting, as well as that by radio emission. We found that the jet power for most of the two subclasses estimated by SED fitting cannot be explained by either the BP or BZ mechanism. While the jet power for most FSRQs estimated by radio flux density can be explained by the BP mechanism, and most BL Lacs can be explained by the BZ mechanism. We also found that FSRQs have higher accretion rates than BL Lacs, implying different accretion disks around their central black holes: FSRQs typically have standard disks, while BL Lacs usually have advection-dominated accretion flow disks.

Keywords: Blazars, Jets, Flat-spectrum radio quasars, Active galactic nuclei
Characterization of Small Flux Ropes Using Juno Spacecraft Cruise-phase Data. In this study, we utilize magnetic field data from the Juno mission's cruise phase to visually identify and analyze 338 interplanetary small flux ropes (SFRs) across a heliocentric distance range of 1─5.5 au. The events are uniformly distributed across heliocentric distances, showing no clear trend. Through superposed epoch analysis, we find that the average SFR magnetic field profiles are symmetric and show little variation across the observed heliocentric distances. Additionally, we observe a slight increasing trend in the mean duration of SFRs, indicating minimal expansion during propagation. Furthermore, we determine that the SFR mean magnetic field dependence on distance is best fit by two separate power laws, exhibiting a steeper decay from 1 to ∼2.1 au and a shallower decay from ∼2.1 to 5.5 au. Near 1 au, the statistical decay rate of the mean magnetic field magnitude of SFRs is slightly higher than that of the interplanetary magnetic field (IMF), suggesting that SFRs may become indistinguishable from the IMF over time. This finding implies that SFRs detected at greater radial distances are possibly generated in situ as opposed to near the Sun. However, only ∼26% of the total population of SFRs in our catalog occurs within 1 day from the heliospheric current sheet (HCS), indicating a very limited association between the occurrence of the majority of SFRs and the presence of the HCS. These results raise questions about the origin of SFRs detected at larger distances, encouraging further exploration for alternatives to the conventional generation mechanisms.

Keywords: Interplanetary magnetic fields