Sazuna/UAT_keywords huggingface dataset:
Probing the Nature of High-redshift Weak Emission Line Quasars: A Young Quasar with a Starburst Host Galaxy. We present the discovery of PSO J083.8371+11.8482, a weak emission line quasar with extreme star formation rate at z = 6.3401. This quasar was selected from Pan-STARRS1, UHS, and unWISE photometric data. Gemini/GNIRS spectroscopy follow-up indicates a Mg II-based black hole mass of ${M}_{\mathrm{BH}}=\left({2.0}_{-0.4}^{+0.7}\right)\times {10}^{9}$ M☉ and an Eddington ratio of ${L}_{\mathrm{bol}}/{L}_{\mathrm{Edd}}={0.5}_{-0.2}^{+0.1}$ , in line with an actively accreting supermassive black hole (SMBH) at z ≳ 6. Hubble Space Telescope imaging sets strong constraint on lens boosting, showing no relevant effect on the apparent emission. The quasar is also observed as a pure point source with no additional emission component. The broad-line region (BLR) emission is intrinsically weak and not likely caused by an intervening absorber. We found rest-frame equivalent widths of EW ${(\mathrm{Ly}\alpha +{\rm{N}}{\rm\small{V}})}_{\mathrm{rest}}=5.7\pm 0.7\,\mathring{\rm A} $ , EW ${({\rm{C}}{\rm\small{IV}})}_{\mathrm{rest}}\leqslant 5.8$ Š(3σ upper limit), and EW ${(\mathrm{Mg}{\rm\small{II}})}_{\mathrm{rest}}=8.7\pm 0.7\,\mathring{\rm A} $ . A small proximity zone size ( ${R}_{{\rm{p}}}=1.2\pm 0.4$ pMpc) indicates a lifetime of only ${t}_{{\rm{Q}}}={10}^{3.4\pm 0.7}$ years from the last quasar phase ignition. ALMA shows extended [C II] emission with a mild velocity gradient. The inferred far-infrared luminosity ( ${L}_{\mathrm{FIR}}=(1.2\pm 0.1)\times {10}^{13}\,{L}_{\odot }$ ) is one of the highest among all known quasar hosts at z ≳ 6. Dust and [C II] emissions put a constraint on the star formation rate of SFR = 900- $4900\,{M}_{\odot }\,{\mathrm{yr}}^{-1}$ , similar to that of a hyperluminous infrared galaxy. Considering the observed quasar lifetime and BLR formation timescale, the weak-line profile in the quasar spectrum is most likely caused by a BLR that is not yet fully formed rather than by continuum boosting by gravitational lensing or a soft continuum due to super-Eddington accretion.

Keywords: AGN host galaxies, Supermassive black holes, Early universe, Quasars, Active galactic nuclei, Intergalactic medium, Reionization
A 60 kpc Galactic Wind Cone in NGC 3079. Galactic winds are associated with intense star formation and active galactic nuclei. Depending on their formation mechanism and velocity, they may remove a significant fraction of gas from their host galaxies, thus suppressing star formation, enriching the intergalactic medium, and shaping the circumgalactic gas. However, the long-term evolution of these winds remains mostly unknown. We report the detection of a wind from NGC 3079 to at least 60 kpc from the galaxy. We detect the wind in far-ultraviolet (FUV) line emission to 60 kpc (as inferred from the broad FUV filter in the Galaxy Evolution Explorer) and X-rays to at least 30 kpc. The morphology, luminosities, temperatures, and densities indicate that the emission comes from shocked material, and the O/Fe ratio implies that the X-ray-emitting gas is enriched by Type II supernovae. If so, the speed inferred from simple shock models is about 500 km s-1, which is sufficient to escape the galaxy. However, the inferred kinetic energy in the wind from visible components is substantially smaller than canonical hot superwind models.

Keywords: Galactic winds, Late-type galaxies, Starburst galaxies
A Wideband Polarization Study of Cygnus A with the Jansky Very Large Array. I. The Observations and Data. We present results from deep, wideband, high spatial and spectral resolution observations of the nearby luminous radio galaxy Cygnus A with the Jansky Very Large Array. The high surface brightness of this source enables detailed polarimetric imaging, providing images at $0\buildrel{\prime\prime}\over{.} 75$ , spanning 2-18 GHz, and at 0"30 (6-18 GHz). The fractional polarization from 2000 independent lines of sight across the lobes decreases strongly with decreasing frequency, with the eastern lobe depolarizing at higher frequencies than the western lobe. The depolarization shows a considerable structure, varying from monotonic to strongly oscillatory. The fractional polarization in general increases with increasing resolution at a given frequency, as expected. However, there are numerous lines of sight with more complicated behavior. We have fitted the $0\buildrel{\prime\prime}\over{.} 3$ images with a simple model incorporating random, unresolved fluctuations in the cluster magnetic field to determine the high-resolution, high-frequency properties of the source and the cluster. From these derived properties, we generated predicted polarization images of the source at lower frequencies, convolved to 0"75. These predictions are remarkably consistent with the observed emission. The observations are consistent with the lower-frequency depolarization being due to unresolved fluctuations on scales ≳ 300-700 pc in the magnetic field and/or electron density superposed on a partially ordered field component. There is no indication in our data of the location of the depolarizing screen or the large-scale field, either or both of which could be located throughout the cluster or in a boundary region between the lobes and the cluster.

Keywords: Spectropolarimetry, Radio galaxies, Intracluster medium, Polarimetry, Extragalactic magnetic fields
The Energetic Thermonuclear Bursts in SAX J1712.6-3739. The neutron star low-mass X-ray binary SAX J1712.6-3739 is known for its long and hard thermonuclear X-ray bursts from previous observations. Its thermonuclear bursts are so distinct as they can last for tens of minutes, as seen with Swift/BAT (E &gt; 15 keV). To explore the origin of these extreme bursts and the nature of SAX J1712.6-3739, we analyzed the observations of all four bursts that were captured by Swift/BAT and derived the peak flux and the fluence of these bursts from joint studies with Swift/XRT and Swift/BAT. The derived bolometric peak fluxes observed by Swift set the distance of SAX J1712.6-3739 to be 4.6-5.6 kpc, while the derived absolute magnitude and average accretion rate agree with its ultracompact nature. Our measurements of the effective duration of these bursts conclude that the 2010 burst corresponds to a normal X-ray burst, the 2011 burst is consistent with an intermediate-duration burst, while the 2014 and the 2018 bursts are more energetic than common intermediate-duration bursts but less energetic than those known superbursts. We estimated that the average mass accretion rate of SAX J1712.6-3739 was about only 0.4%-0.7% ${\dot{{\text{}}M}}_{\mathrm{Edd}}$ . Current theory predicts no carbon production in the bursters under such low accretion rate. If true, the 2014 and 2018 bursts are then deep helium bursts instead of carbon bursts. The thermonuclear bursts of SAX J1712.6-3739 have shown a very wide range of durations. The ignition model predicts that the diverse burst durations are induced by variable accretion rates, but current results provide only weak support to this inference.

Keywords: Neutron stars, X-ray binary stars, X-ray bursts
Dynamics of Companion Galaxies of Early-type Galaxies. We estimated the dynamical masses of 115 early-type galaxies (ETGs) by analyzing the dynamics of satellite and companion galaxies of these ETGs. We selected galaxies with absolute magnitudes between -22 and -25 in the Ks-band from the Extragalactic Distance Database. We also selected 216 spiral galaxies for comparison. We employed a simple model to simulate the observed dynamical mass from satellite galaxies at various distances. Our simulations showed that the dynamical masses derived from satellite galaxies with elliptical orbits would be smaller than those with circular orbits even though they contain the same dark mass halos. Therefore, relationships between the observed Mdyn/Mb distributions and distances would depend on orbital shapes. From the relationships between our observed Mdyn/Mb distributions and distances, we suggest that the satellite galaxies of the ETGs have relatively more elliptical orbits than those of the spiral galaxies and the Mdyn/Mb of the ETGs are greater than those of the spiral galaxies.

Keywords: Galaxy dark matter halos, Galaxy evolution, Early-type galaxies
Heated Poles on the Companion of Redback PSR J2339-0533. We analyze the photometry and spectra of the "redback" millisecond pulsar binary J2339-0533. These observations include new measurements from Keck and the Gamma-Ray Burst Optical/Near-infrared Detector (GROND), as well as archival measurements from the Optical and Infrared Synergetic Telescopes for Education and Research (OISTER), WIYN, Southern Astrophysical Research (SOAR), and Hobby-Eberly Telescope (HET) telescopes. The parameters derived from GROND, our primary photometric data, describe well the rest of the data sets, raising our confidence in our fitted binary properties. Our fit requires hot spots (likely magnetic poles) on the surface of the companion star, and we see evidence that these spots move over the 8 yr span of our photometry. The derived binary inclination i = 69°3 ± 2°3, together with the center-of-mass velocity (from the radial-velocity fits) KC = 347.0 ± 3.7 $\mathrm{km}\,{{\rm{s}}}^{-1}$ , give a fairly typical neutron star mass of 1.47 ± 0.09 M⊙.

Keywords: Pulsars
Three-dimensional Modeling of the Magnetothermal Evolution of Neutron Stars: Method and Test Cases. Neutron stars harbor extremely strong magnetic fields within their solid outer crust. The topology of this field strongly influences the surface temperature distribution and, hence, the star's observational properties. In this work, we present the first realistic simulations of the coupled crustal magnetothermal evolution of isolated neutron stars in three dimensions accounting for neutrino emission, obtained with the pseudo-spectral code PARODY. We investigate both the secular evolution, especially in connection with the onset of instabilities during the Hall phase, and the short-term evolution following episodes of localized energy injection. Simulations show that a resistive tearing instability develops in about a Hall time if the initial toroidal field exceeds $\approx {10}^{15}$ G. This leads to crustal failures because of the huge magnetic stresses coupled with the local temperature enhancement produced by dissipation. Localized heat deposition in the crust results in the appearance of hot spots on the star surface, which can exhibit a variety of patterns. Because the transport properties are strongly influenced by the magnetic field, the hot regions tend to drift away and get deformed following the magnetic field lines while cooling. The shapes obtained with our simulations are reminiscent of those recently derived from NICER X-ray observations of the millisecond pulsar PSR J0030+0451.

Keywords: Neutron stars, Stellar magnetic fields, Pulsars, Magnetars, Magnetohydrodynamical simulations
On the Size of the Flare Associated with the Solar Proton Event in 774 AD. The 774 AD solar proton event (SPE) detected in cosmogenic nuclides had an inferred &gt;1 GV (&gt;430 MeV) fluence estimated to have been ∼30-70 times larger than that of the 1956 February 23 ground level event (GLE). The 1956 GLE was itself ∼2.5 times larger at &gt;430 MeV than the episode of strong GLE activity from 1989 August-October. We use an inferred soft X-ray (SXR) class of X20 ± 10 for the 1956 February 23 eruptive flare as a bridge to the source flare for the 774 SPE. A correlation of the &gt;200 MeV proton fluences of hard-spectra post-1975 GLEs with the SXR peak fluxes of their associated flares yields an SXR flare class of X285 ± 140 (bolometric energy of ∼(1.9 ± 0.7) × 1033 erg) for the 774 flare. This estimate is within theoretical determinations of the largest flare the Sun could produce based on the largest spot group yet observed. Assuming a single eruptive flare source for the 774 SPE, the above estimate indicates that the Sun can produce a threshold-level 1033 erg superflare. If the 774 event originated in two closely timed, equal-fluence SPEs, the inferred flare size drops to X180 ± 90 (∼(1.4 ± 0.5) × 1033 erg). We speculate on favorable solar conditions that can lead to enhanced shock acceleration of high-energy protons in eruptive flares.

Keywords: Solar energetic particles, Solar coronal mass ejection shocks, The Sun, Solar flares
A Search for In Situ Field OB Star Formation in the Small Magellanic Cloud. Whether any OB stars form in isolation is a question central to theories of massive star formation. To address this, we search for tiny, sparse clusters around 210 field OB stars in the Small Magellanic Cloud (SMC) from the Runaways and Isolated O-Type Star Spectroscopic Survey of the SMC (RIOTS4), using friends-of-friends and nearest neighbors algorithms. We also stack the target fields to evaluate the presence of an aggregate density enhancement. Using several statistical tests, we compare these observations with three random-field data sets, and we also compare the known runaways to nonrunaways. We find that the local environments of nonrunaways show higher aggregate central densities than for runaways, implying the presence of some "tips of icebergs" (TIB) clusters. We find that the frequency of these tiny clusters is low, ∼4%-5% of our sample. This fraction is much lower than some previous estimates, but is consistent with field OB stars being almost entirely runaway and walkaway stars. The lack of TIB clusters implies that such objects either evaporate on short timescales or do not form, implying a higher cluster lower-mass limit and consistent with a relationship between maximum stellar mass (mmax) and the mass of the cluster (Mcl). On the other hand, we also cannot rule out that some OB stars may form in highly isolated conditions. Our results set strong constraints on the formation of massive stars in relative isolation.

Keywords: Initial mass function, Multiple star evolution, Massive stars, Small Magellanic Cloud, Field stars, Galaxy stellar content, OB associations, OB stars, Star formation, Open star clusters, Runaway stars, Star clusters
Runaway OB Stars in the Small Magellanic Cloud: Dynamical versus Supernova Ejections. Runaway OB stars are ejected from their parent clusters via two mechanisms, both involving multiple stars: the dynamical ejection scenario (DES) and the binary supernova scenario (BSS). We constrain the relative contributions from these two ejection mechanisms in the Small Magellanic Cloud (SMC) using data for 304 field OB stars from the spatially complete Runaways and Isolated O-Type Star Spectroscopic Survey of the SMC (RIOTS4). We obtain stellar masses and projected rotational velocities ${v}_{r}\sin \ i$ for the sample using RIOTS4 spectra, and we use transverse velocities ${v}_{\mathrm{loc}}$ from Gaia DR2 proper motions. Kinematic analyses of the masses, ${v}_{r}\sin \ i$ , noncompact binaries, high-mass X-ray binaries, and Oe/Be stars largely support predictions for the statistical properties of the DES and BSS populations. We find that dynamical ejections dominate over supernova ejections by a factor of ∼2-3 in the SMC, and our results suggest a high frequency of DES runaways and binary ejections. Objects seen as BSS runaways also include two-step ejections of binaries that are reaccelerated by supernova kicks. We find that two-step runaways likely dominate the BSS runaway population. Our results further imply that any contribution from in situ field OB star formation is small. Finally, our data strongly support the post-mass-transfer model for the origin of classical Oe/Be stars, providing a simple explanation for the bimodality in the ${v}_{r}\sin \ i$ distribution and high, near-critical, Oe/Be rotation velocities. The close correspondence of Oe/Be stars with BSS predictions implies that the emission-line disks are long-lived.

Keywords: Binary stars, Stellar kinematics, Massive stars, Small Magellanic Cloud, Field stars, High mass x-ray binary stars, Stellar rotation, Be stars, Runaway stars, Star clusters
The Extreme Red Excess in Blazar Ultraviolet Broad Emission Lines. We present a study of quasars with very redward asymmetric (RA) ultraviolet (UV) broad emission lines (BELs). An excess of redshifted emission has been previously shown to occur in the BELs of radio-loud quasars and is most extreme in certain blazars. Paradoxically, blazars are objects that are characterized by a highly relativistic blueshifted outflow toward Earth. We show that the red emitting gas resides in a very broad component (VBC) that is typical of Population B quasars that are defined by a wide Hβ BEL profile. Empirically, we find that RA BEL blazars have both low Eddington rates (≲1%) and an inordinately large (order unity) ratio of long-term time-averaged jet power to accretion luminosity. The latter circumstance has been previously shown to be associated with a depressed extreme UV ionizing continuum. Both properties conspire to produce a low flux of ionizing photons, two orders of magnitude less than typical Population B quasars. We use CLOUDY models to demonstrate that a weak ionizing flux is required for gas near the central black hole to be optimally ionized to radiate BELs with high efficiency (most quasars overionize nearby gas, resulting in low radiative efficiency). The large gravitational redshift and transverse Doppler shift result in a VBC that is redshifted by ∼2000-5000 km s-1 with a correspondingly large line width. The RA BELs result from an enhanced efficiency (relative to typical Population B quasars) to produce a luminous, redshifted VBC near the central black hole.

Keywords: Quasars
Populating the Upper Black Hole Mass Gap through Stellar Collisions in Young Star Clusters. Theoretical modeling of massive stars predicts a gap in the black hole (BH) mass function above ∼40-50 M⊙ for BHs formed through single star evolution, arising from (pulsational) pair-instability supernovae (PISNe). However, in dense star clusters, dynamical channels may exist that allow construction of BHs with masses in excess of those allowed from single star evolution. The detection of BHs in this so-called "upper-mass gap" would provide strong evidence for the dynamical processing of BHs prior to their eventual merger. Here, we explore in detail the formation of BHs with masses within or above the pair-instability gap through collisions of young massive stars in dense star clusters. We run a suite of 68 independent cluster simulations, exploring a variety of physical assumptions pertaining to growth through stellar collisions, including primordial cluster mass segregation and the efficiency of envelope stripping during collisions. We find that as many as ∼20% of all BH progenitors undergo one or more collisions prior to stellar collapse and up to ∼1% of all BHs reside within or above the pair-instability gap through the effects of these collisions. We show that these BHs readily go on to merge with other BHs in the cluster, creating a population of massive BH mergers at a rate that may compete with the "multiple-generation" merger channel described in other analyses. This has clear relevance for the formation of very massive BH binaries as recently detected by the Laser Interferometer Gravitational-Wave Observatory/Virgo in GW190521. Finally, we describe how stellar collisions in clusters may provide a unique pathway to PISNe and briefly discuss the expected rate of these events and other electromagnetic transients.

Keywords: Globular star clusters, Gravitational waves, Stellar mass black holes
Simultaneous Evolution of the Virial Parameter and Star Formation Rate in Molecular Clumps Undergoing Global Hierarchical Collapse. We compare dense clumps and cores in a numerical simulation of molecular clouds (MCs) undergoing global hierarchical collapse (GHC) to observations in two MCs at different evolutionary stages, the Pipe and the G14.225 clouds, to test the ability of the GHC scenario to follow the early evolution of the energy budget and star formation activity of these structures. In the simulation, we select a region that contains cores of sizes and densities similar to the Pipe cores and find that it evolves through accretion, developing substructure similar to that of the G14.225 cloud after ∼1.6 Myr. Within this region, we follow the evolution of the Larson ratio ${ \mathcal L }\equiv {\sigma }_{{\rm{v}}}/{R}^{1/2}$ , where ${\sigma }_{{\rm{v}}}$ is the velocity dispersion and R is the size; the virial parameter α; and the star formation activity of the cores/clumps. In the simulation, we find that as the region evolves, (i) its clumps have ${ \mathcal L }$ and α values first consistent with those of the Pipe substructures and later with those of G14.225; (ii) the individual cores first exhibit a decrease in α followed by an increase when star formation begins; (iii) collectively, the ensemble of cores/clumps reproduces the observed trend of lower α for higher-mass objects; and (iv) the star formation rate and star formation efficiency increase monotonically. We suggest that this evolution is due to the simultaneous loss of externally driven compressive kinetic energy and increase of the self-gravity-driven motions. We conclude that the GHC scenario provides a realistic description of the evolution of the energy budget of the clouds&amp;' substructure at early times, which occurs simultaneously with an evolution of the star formation activity.

Keywords: Scaling relations, Molecular clouds, Interstellar medium, Collapsing clouds
The Massive Ancient Galaxies at z &gt; 3 NEar-infrared (MAGAZ3NE) Survey: Confirmation of Extremely Rapid Star Formation and Quenching Timescales for Massive Galaxies in the Early Universe. We present near-infrared spectroscopic confirmations of a sample of 16 photometrically selected galaxies with stellar masses $\mathrm{log}({M}_{* }/{M}_{\odot })$ &gt;11 at redshift z &gt; 3 from the XMM-VIDEO and COSMOS-UltraVISTA fields using Keck/MOSFIRE as part of the Massive Ancient Galaxies At z &gt; 3 NEar-infrared (MAGAZ3NE) survey. Eight of the ultramassive galaxies (UMGs) have specific star formation rates (sSFR) &lt; 0.03 Gyr-1, with negligible emission lines. Another seven UMGs show emission lines consistent with active galactic nuclei and/or star formation, while only one UMG has sSFR &gt; 1 Gyr-1. Model star formation histories of these galaxies describe systems that formed the majority of their stars in vigorous bursts of several hundred megayear duration around $4\lt z\lt 6$ during which hundreds to thousands of solar masses were formed per year. These formation ages of &lt;1 Gyr prior to observation are consistent with ages derived from measurements of Dn(4000) and ${{EW}}_{0}$ (Hδ). Rapid quenching followed these bursty star-forming periods, generally occurring less than 350 Myr before observation, resulting in post-starburst SEDs and spectra for half the sample. The rapid formation timescales are consistent with the extreme star formation rates observed in $4\lt z\lt 7$ dusty starbursts observed with ALMA, suggesting that such dusty galaxies are progenitors of these UMGs. While such formation histories have been suggested in previous studies, the large sample introduced here presents the most compelling evidence yet that vigorous star formation followed by rapid quenching is almost certainly the norm for high-mass galaxies in the early universe. The UMGs presented here were selected to be brighter than Ks = 21.7, raising the intriguing possibility that even (fainter) older quiescent UMGs could exist at this epoch. * The spectra presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

Keywords: Quenched galaxies, High-redshift galaxies, Galaxy evolution