Sazuna/UAT_keywords huggingface dataset:
The Earliest Candidates of Auroral Observations in Assyrian Astrological Reports: Insights on Solar Activity around 660 BCE. Auroral records found in historical archives and cosmogenic isotopes found in natural archives have served as sound proxies of coronal mass ejections and solar energetic particles (SEPs), respectively, for dates prior to the onset of telescopic sunspot observations in 1610. These space weather events constitute a significant threat to a modern civilization, because of its increasing dependency on an electronic infrastructure. Recent studies have identified multiple extreme space weather events derived from SEPs in natural archives, such as the event in 660 BCE. While the level of solar activity around 660 BCE is of great interest, this had not been within the coverage of the hitherto-known datable auroral records in historical documents that extend back to the 6th century BCE. Therefore, we have examined Assyrian astrological reports in the 8th and 7th centuries BCE, identified three observational reports of candidate aurorae, and dated these reports to approximately 680 BCE-650 BCE. The Assyrian cuneiform tablets let us extend the history of auroral records and solar activity by a century. These cuneiform reports are considered to be the earliest datable records of candidate aurorae and they support the concept of enhanced solar activity suggested by the cosmogenic isotopes from natural archives.

Keywords: Geomagnetic fields, History of astronomy, Solar coronal mass ejections, Solar activity, Solar-terrestrial interactions
Evidence for Low Radiative Efficiency or Highly Obscured Growth of z &gt; 7 Quasars. The supermassive black holes (SMBHs) observed at the centers of all massive galaxies are believed to have grown via luminous accretion during quasar phases in the distant past. The fraction of inflowing rest mass energy emitted as light, the radiative efficiency, has been inferred to be 10%, in agreement with expectations from thin disk accretion models. But the existence of billion solar-mass SMBHs powering quasars at z &gt; 7 challenges this picture: provided they respect the Eddington limit, there is not enough time to grow z &gt; 7 SMBHs from stellar remnant seeds unless the radiative efficiency is below 10%. Here we show that one can constrain the radiative efficiencies of the most distant quasars known using foreground neutral intergalactic gas as a cosmological-scale ionizing photon counter. From the Lyα absorption profiles of ULAS J1120+0641 (z = 7.09) and ULAS J1342+0928 (z = 7.54), we determine posterior median radiative efficiencies of 0.08% and 0.1%, respectively, and the combination of the two measurements rules out the canonical 10% efficiency at 99.8% credibility after marginalizing over the unknown obscured fraction. This low radiative efficiency implies rapid mass accretion for the earliest SMBHs, greatly easing the tension between the age of the universe and the SMBH masses. However, our measured efficiency may instead reflect nearly complete obscuration by dusty gas in the quasar host galaxies over the vast majority of their SMBH growth. Assuming 10% efficiency during unobscured phases, we find that the obscured fraction would be &gt;82% at 95% credibility, and imply a {25.7}-16.5+49.6 times larger obscured than unobscured luminous quasar population at z &gt; 7.

Keywords: Supermassive black holes, Reionization, Quasars
COS Observations of the Cosmic Web: A Search for the Cooler Components of a Hot, X-Ray Identified Filament. In the local universe, a large fraction of the baryon content is believed to exist as diffuse gas in filaments. While this gas is directly observable in X-ray emission around clusters of galaxies, it is primarily studied through its UV absorption. Recently, X-ray observations of large-scale filaments connecting to the cosmic web around the nearby (z = 0.05584) cluster A133 were reported. One of these filaments is intersected by the sightline to quasar [VV98] J010250.2-220929, allowing for a first-ever census of cold, cool, and warm gas in a filament of the cosmic web where hot gas has been seen in X-ray emission. Here, we present UV observations with the Cosmic Origins Spectrograph and optical observations with the Magellan Echellette spectrograph of [VV98] J010250.2-220929. We find no evidence of cold, cool, or warm gas associated with the filament. In particular, we set a 2σ upper limit on Lyα absorption of log(N H I /cm-2) &lt; 13.7, assuming a Doppler parameter of b = 20 km s-1. As this sightline is ∼1100 pkpc (0.7R vir) from the center of A133, we suggest that all gas in the filament is hot at this location, or that any warm, cool, or cold components are small and clumpy. A broader census of this system—combining more UV sightlines, deeper X-ray observations, and a larger redshift catalog of cluster members—is needed to better understand the roles of filaments around clusters.

Keywords: Hot intergalactic medium, Galaxy clusters, Quasar absorption line spectroscopy, Intergalactic medium phases, Cool intergalactic medium, Cosmic web, Intergalactic medium, Warm-hot intergalactic medium, Intracluster medium
X-Ray Fluorescence from Super-Eddington Accreting Black Holes. X-ray reverberation has proven to be a powerful tool capable of probing the innermost region of accretion disks around compact objects. Current theoretical effort generally assumes that the disk is geometrically thin, optically thick, and orbiting with Keplerian speed. Thus, these models cannot be applied to systems where super-Eddington accretion happens because the thin disk approximation fails in this accretion regime. Furthermore, state-of-the-art numerical simulations show that optically thick winds are launched from the super-Eddington accretion disks, thereby changing the reflection geometry significantly from the thin disk picture. We carry out theoretical investigations on this topic by focusing on the Fe Kα fluorescent lines produced from super-Eddington disks, and show that their line profiles are shaped by the funnel geometry and wind acceleration. We also systematically compare the Fe line profiles from super-Eddington thick disks to those from thin disks, and find that the former are substantially more blueshifted and symmetric in shape. These results are consistent with the observed Fe Kα line from the jetted tidal disruption event, Swift J1644, in which a transient super-Eddington accretion disk was formed out of stellar debris. Therefore, careful analysis of the Fe Kα line profile can be used to identify systems undergoing super-Eddington accretion.

Keywords: Accretion, Black hole physics, Galaxy accretion disks, Emission line galaxies, Magnetohydrodynamical simulations
Hidden Planets: Implications from ’Oumuamua and DSHARP. The discovery of ’Oumuamua (1I/2017 U1), the first interstellar interloper, suggests an abundance of free-floating small bodies whose ejection into galactic space cannot be explained by the current population of confirmed exoplanets. Shortly after ’Oumuamua’s discovery, observational results from the Disk Substructures at High Angular Resolution Project (DSHARP) illustrated the near ubiquity of ring/gap substructures within protoplanetary disks, strongly suggesting the existence of a vast population of as-yet undetected wide-separation planets that are capable of efficiently ejecting debris from their environments. These planets have a ≳ 5 au and masses on the order of Neptune’s mass or larger, and they may accompany ∼50% of newly formed stars. We combine the DSHARP results with statistical constraints from current time-domain surveys to quantify the population of detectable icy planetesimals ejected by disk-embedded giant planets through gravity assists. Assessment of the expected statistical distribution of interstellar objects (ISOs) is critical to accurately plan for and interpret future detections. We show that the number density of ISOs implied by ’Oumuamua is consistent with ’Oumuamua itself having originated as an icy planetesimal ejected from a DSHARP-type system via gravity assists, with the caveat that ’Oumuamua’s lack of observed outgassing remains in strong tension with a cometary origin. Under this interpretation, ’Oumuamua’s detection points toward a large number of long-period giant planets in extrasolar systems, supporting the hypothesis that the observed gaps in protoplanetary disks are carved by planets. In the case that ’Oumuamua is an ejected cometary planetesimal, we conclude that the Large Synoptic Survey Telescope (LSST) should detect up to a few ISOs per year of ’Oumuamua’s size or larger and over 100 yr-1 for objects with r &gt; 1 m.

Keywords: Exoplanet dynamics, Ejecta, Small Solar System bodies, Solar system, Planetary system formation, Protoplanetary disks, Planetary science, Comets, Planet formation
A Family Picture: Tracing the Dynamical Path of the Structural Properties of Multiple Populations in Globular Clusters. We studied the spatial distributions of multiple stellar populations (MPs) in a sample of 20 globular clusters (GCs) spanning a broad range of dynamical ages. The differences between first-population (FP) and second-population (SP) stars were measured by means of the parameter A +, defined as the area enclosed between their cumulative radial distributions. We provide the first purely observational evidence of the dynamical path followed by MPs from initial conditions toward a complete FP-SP spatial mixing. Less dynamically evolved clusters have SP stars more centrally concentrated than FPs, while in more dynamically evolved systems the spatial differences between FP and SP stars decrease and eventually disappear. By means of an appropriate comparison with a set of numerical simulations, we show that these observational results are consistent with the evolutionary sequence expected by the long-term dynamical evolution of clusters forming with an initially more centrally concentrated SP subsystem. This result is further supported by the evidence of a trend between A + and the stage of GC dynamical evolution inferred by the ratio between the present-day and the initial mass of the cluster.

Keywords: Globular star clusters, Broad band photometry, Dynamical evolution, HST photometry, Giant branch, Hertzsprung Russell diagram, Star clusters
The Star Formation History and Dynamics of the Ultra-diffuse Galaxy Dragonfly 44 in MOND and MOG. The observed line-of-sight velocity dispersion σ los of the ultra-diffuse galaxy Dragonfly 44 (DF44) requires a Newtonian dynamical mass-to-light ratio of {M}dyn}/{L}I={26}-6+7 solar units. This is well outside the acceptable limits of our stellar population synthesis (SPS) models, which we construct using the integrated galactic initial mass function (IGIMF) theory. Assuming DF44 is in isolation and using Jeans analysis, we calculate σ los profiles of DF44 in Milgromian dynamics (MOND) and modified gravity (MOG) theories without invoking dark matter. Comparing with the observed kinematics, the best-fitting MOND model has {M}dyn}/{L}I={3.6}-1.2+1.6 and a constant orbital anisotropy of β =-{0.5}-1.6+0.4. In MOG, we first fix its two theoretical parameters α and μ based on previous fits to the observed rotation curve data of The HI Nearby Galaxy Survey (THINGS). The DF44 σ los profile is best fit with {M}dyn}/{L}I={7.4}-1.4+1.5, larger than plausible SPS values. MOG produces a σ los profile for DF44 with acceptable M dyn/L  I  and isotropic orbits if α and μ are allowed to vary. MOND with the canonical a 0 can explain DF44 at the 2.40σ confidence level (1.66%) if considering both its observed kinematics and typical star formation histories in an IGIMF context. However, MOG is ruled out at 5.49σ (P-value of 4.07 × 10-8) if its free parameters are fixed at the highest values consistent with THINGS data.

Keywords: Gravitation, Galaxy dynamics, Dwarf galaxies, Modified Newtonian dynamics
The FRB 121102 Host Is Atypical among Nearby Fast Radio Bursts. We search for host galaxy candidates of nearby fast radio bursts (FRBs), FRB 180729.J1316+55, FRB 171020, FRB 171213, FRB 180810.J1159+83, and FRB 180814.J0422+73 (the second repeating FRB). We compare the absolute magnitudes and the expected host dispersion measure DMhost of these candidates with that of the first repeating FRB, FRB 121102, as well as those of long gamma-ray bursts (LGRBs) and superluminous supernovae (SLSNe), the proposed progenitor systems of FRB 121102. We find that while the FRB 121102 host is consistent with those of LGRBs and SLSNe, the nearby FRB host candidates, at least for FRB 180729.J1316+55, FRB 171020, and FRB 180814.J0422+73, either have a smaller DMhost or are fainter than FRB 121102 host, as well as the hosts of LGRBs and SLSNe. In order to avoid the uncertainty in estimating DMhost due to the line-of-sight effect, we propose a galaxy-group-based method to estimate the electron density in the intergalactic regions, and hence, DMIGM. The result strengthens our conclusion. We conclude that the host galaxy of FRB 121102 is atypical, and LGRBs and SLSNe are likely not the progenitor systems of at least most nearby FRB sources. The recently reported two FRB hosts differ from the host of FRB 121102 and also the host candidates suggested in this paper. This is consistent with the conclusion of our paper and suggests that the FRB hosts are very diverse.

Keywords: Radio bursts, Radio astronomy, High energy astrophysics, Radio transient sources
Molecular Cloud Origin for Oxygen Isotopic Heterogeneity Recorded by a Primordial Spinel-rich Refractory Inclusion. A spinel-rich, layered calcium- aluminum-rich spherule from the MIL 090019 CO3 chondrite contains a spinel core with a relatively 16O-rich (Δ17O ∼ -18‰) and mass-fractionated oxygen isotopic composition surrounded by minerals, including spinel, that are relatively 16O-poor (Δ17O ∼ -7‰), which are in turn surrounded by layers of 16O-enriched silicates (Δ17O ∼ -17‰). Inclusions with refractory mineral assemblages such as this one are proposed to record inner nebula processes during the earliest epoch of solar nebula evolution. Mineralogical and textural analyses indicate that this primordial particle formed by high-temperature gas-solid reactions, partial melting, evaporation, and condensation. The radially distributed oxygen isotopic heterogeneity measured among multiple occurrences of several minerals, including spinel, requires the existence of 16O-poor gas at the beginning of solar system formation, 105 yr earlier than it can be produced by photochemical self-shielding in the solar nebula and introduced to the inner protoplanetary disk.

Keywords: Pre-solar nebulae, Solar system formation, Meteorite composition, Protoplanetary nebulae, Carbonaceous chondrites, Molecular clouds, Photodissociation regions, Protoplanetary disks, Meteorites
The Physical Origins of the Identified and Still Missing Components of the Warm-Hot Intergalactic Medium: Insights from Deep Surveys in the Field of Blazar 1ES1553+113. The relationship between galaxies and the state/chemical enrichment of the warm-hot intergalactic medium (WHIM) expected to dominate the baryon budget at low-z provides sensitive constraints on structure formation and galaxy evolution models. We present a deep redshift survey in the field of 1ES1553+113, a blazar with a unique combination of ultraviolet (UV)+X-ray spectra for surveys of the circumgalactic/intergalactic medium (CGM/IGM). Nicastro et al. reported the detection of two O VII WHIM absorbers at z = 0.4339 and 0.3551 in its spectrum, suggesting that the WHIM is metal rich and sufficient to close the missing baryons problem. Our survey indicates that the blazar is a member of a z = 0.433 group and that the higher-z O VII candidate arises from its intragroup medium. The resulting bias precludes its use in baryon censuses. The z = 0.3551 candidate occurs in an isolated environment 630 kpc from the nearest galaxy (with stellar mass {log}{M}* /{M}⊙ ≈ 9.7), which we show is unexpected for the WHIM. Finally, we characterize the galactic environments of broad H I Lyα absorbers (Doppler widths of b = 40-80 km s-1 T ≲ 4 × 105 K) that provide metallicity-independent WHIM probes. On average, broad Lyα absorbers are ≈2× closer to the nearest luminous (L &gt; 0.25L *) galaxy (700 kpc) than narrow (b &lt; 30 km s-1 T ≲ 4 × 105 K) ones (1300 kpc) but ≈2× further than O VI absorbers (350 kpc). These observations suggest that gravitational collapse heats portions of the IGM to form the WHIM, but with feedback that does not enrich the IGM far beyond galaxy/group halos to levels currently observable in UV/X-ray metal lines.

Keywords: Blazars, Quasar absorption line spectroscopy, Intergalactic medium
The Reliability of the Low-latency Estimation of Binary Neutron Star Chirp Mass. The LIGO and Virgo Collaborations currently conduct searches for gravitational waves from compact binary coalescences in real time. For promising candidate events, a sky map and distance estimation are released in low latency to facilitate their electromagnetic follow-up. Currently, no information is released about the masses of the compact objects. Recently, Margalit &amp; Metzger suggested that knowledge of the chirp mass of the detected binary neutron stars could be useful to prioritize the electromagnetic follow-up effort, and urged the LIGO-Virgo collaboration to release chirp mass information in low latency. One might worry that low-latency searches for compact binaries make simplifying assumptions that could introduce biases in the mass parameters: neutron stars are treated as point particles with dimensionless spins below 0.05 perfectly aligned with the orbital angular momentum. Furthermore, the template bank used to search for them has a finite resolution. In this paper we show that none of these limitations can introduce chirp mass biases larger than ∼10-3 M ⊙. Even the total mass is usually accurately estimated, with biases smaller than 6%. The mass ratio and effective inspiral spins, on the other hand, can suffer from more severe biases.

Keywords: Gravitational wave astronomy, Neutron stars, Compact binary stars, Gravitational waves
CDF-S XT1 and XT2: White Dwarf Tidal Disruption Events by Intermediate-mass Black Holes?. Recently, two fast X-ray transients (XT1 and XT2) have been reported from the search in the Chandra Deep Field (CDF) data. Each transient shows an initial plateau lasting around hundreds to thousands of seconds followed by a rapid decay in the light curve. In particular, CDF-S XT2 is found to be associated with a galaxy at redshift z = 0.738 and was explained as a counterpart of a binary neutron-star merger event. In this Letter, motivated by the short duration and decay slopes of the two transients, we consider an alternative interpretation in which both events are accretion-driven flares from tidal disruption of white dwarfs by intermediate-mass black holes. We derive a theoretical model of the accretion rate history and find that it fits the observed X-ray light curves well. The extremely super-Eddington peak luminosity of XT2 can be explained by the beaming effect of the system, likely in the form of a jet.

Keywords: X-ray transient sources, Intermediate-mass black holes, Tidal disruption, White dwarf stars
Detection of Phosphorus-bearing Molecules toward a Solar-type Protostar. Phosphorus is a key ingredient in terrestrial biochemistry, but is rarely observed in the molecular interstellar medium and therefore little is known about how it is inherited during the star and planet formation sequence. We present observations of the phosphorus-bearing molecules PO and PN toward the Class I low-mass protostar B1-a using the IRAM 30 m telescope, representing the second detection of phosphorus carriers in a solar-type star-forming region. The P/H abundance contained in PO and PN is ∼10-10-10-9 depending on the assumed source size, accounting for just 0.05%-0.5% of the solar phosphorus abundance and implying significant sequestration of phosphorus in refractory material. Based on a comparison of the PO and PN line profiles with the shock tracers SiO, SO2, and CH3OH, the phosphorus molecule emission seems to originate from shocked gas and is likely associated with a protostellar outflow. We find a PO/PN column density ratio of ∼1-3, which is consistent with the values measured in the shocked outflow of the low-mass protostar L1157, the massive star-forming regions W51 and W3(OH), and the galactic center GMC G+0.693-0.03. This narrow range of PO/PN ratios across sources with a range of environmental conditions is surprising, and likely encodes information on how phosphorus carriers are stored in grain mantles.

Keywords: Interstellar molecules, Protostars, Astrochemistry
Puffy Accretion Disks: Sub-Eddington, Optically Thick, and Stable. We report on a new class of solutions of black hole accretion disks that we have found through three-dimensional, global, radiative magnetohydrodynamic simulations in general relativity. It combines features of the canonical thin, slim, and thick disk models but differs in crucial respects from each of them. We expect these new solutions to provide a more realistic description of black hole disks than the slim disk model. We are presenting a disk solution for a nonspinning black hole at a sub-Eddington mass accretion rate, \dot{M}=0.6 {\dot{M}}Edd}. By the density scale-height measure the disk appears to be thin, having a high density core near the equatorial plane of height {h}ρ ∼ 0.1 r, but most of the inflow occurs through a highly advective, turbulent, optically thick, Keplerian region that sandwiches the core and has a substantial geometrical thickness comparable to the radius, H ∼ r. The accreting fluid is supported above the midplane in large part by the magnetic field, with the gas and radiation to magnetic pressure ratio β ∼ 1, this makes the disk thermally stable, even though the radiation pressure strongly dominates over gas pressure. A significant part of the radiation emerging from the disk is captured by the black hole, so the disk is less luminous than a thin disk would be at the same accretion rate.

Keywords: Accretion, Radiative magnetohydrodynamics, Black holes, General relativity, Magnetohydrodynamical simulations
A New Type of Jet in a Polar Limb of the Solar Coronal Hole. A new type of chromospheric jet in a polar limb of a coronal hole is discovered in the Ca II filtergram of the Solar Optical Telescope on board the Hinode. We identify 30 jets in a filtered Ca II movie with a duration of 53 minutes. The average speed at their maximum heights is found to be 132 ± 44 km s-1 ranging from 57 to 264 km s-1 along the propagation direction. The average lifetime is 20 ± 6 ranging from 11 to 36 s. The speed and lifetime of the jets are located at end-tails of those parameters determined for type II spicules, hence implying a new type of jets. To confirm whether these jets are different from conventional spicules, we construct a time-height image averaged over a horizontal region of 1″, and calculate lagged cross-correlations of intensity profiles at each height with the intensity at 2 Mm. From this, we obtain a cross-correlation map as a function of lag and height. We find that the correlation curve as a function of lag time is well fitted into three different Gaussian functions whose standard deviations of the lag time are 193, 42, and 17 s. The corresponding propagation speeds are calculated to be 9 km s-1, 67 km s-1, and 121 km s-1, respectively. The kinematic properties of the former two components seem to correspond to the 3-minute oscillations and type II spicules, while the latter component to the jets is addressed in this study.

Keywords: Solar optical telescopes, Solar chromosphere, Astronomy data analysis