Sazuna/UAT_keywords huggingface dataset:
Constraints on the Dense Matter Equation of State and Neutron Star Properties from NICER's Mass-Radius Estimate of PSR J0740+6620 and Multimessenger Observations. In recent years our understanding of the dense matter equation of state (EOS) of neutron stars has significantly improved by analyzing multimessenger data from radio/X-ray pulsars, gravitational wave events, and from nuclear physics constraints. Here we study the additional impact on the EOS from the jointly estimated mass and radius of PSR J0740+6620, presented in Riley et al. by analyzing a combined data set from X-ray telescopes NICER and XMM-Newton. We employ two different high-density EOS parameterizations: a piecewise-polytropic (PP) model and a model based on the speed of sound in a neutron star (CS). At nuclear densities these are connected to microscopic calculations of neutron matter based on chiral effective field theory (EFT) interactions. In addition to the new NICER data for this heavy neutron star, we separately study constraints from the radio timing mass measurement of PSR J0740+6620, the gravitational wave events of binary neutron stars GW190425 and GW170817, and for the latter the associated kilonova AT2017gfo. By combining all these, and the NICER mass-radius estimate of PSR J0030+0451, we find the radius of a 1.4 M☉ neutron star to be constrained to the 95% credible ranges ${12.33}_{-0.81}^{+0.76}\,\mathrm{km}$ (PP model) and ${12.18}_{-0.79}^{+0.56}\,\mathrm{km}$ (CS model). In addition, we explore different chiral EFT calculations and show that the new NICER results provide tight constraints for the pressure of neutron star matter at around twice saturation density, which shows the power of these observations to constrain dense matter interactions at intermediate densities.

Keywords: X-ray astronomy, Bayesian statistics, Neutron star cores, Pulsars, Gravitational wave astronomy, Nuclear astrophysics, Gravitational waves, Compact objects
Universal Relation between the Variances of Distortions of Gravitational Waves owing to Gravitational Lensing. Gravitational waves from the distant sources are gravitationally lensed during their propagation through the intervening matter inhomogeneities before arriving at detectors. It has been proposed in the literature that the variance of the lensed waveform can be used to extract information of the matter power spectrum at very small scales and of low-mass dark halos. In this Letter, we show that the variance of the amplitude fluctuation and that of the phase fluctuation of the lensed waveform obey a simple relation irrespective of the shape of the matter power spectrum. We study conditions under which this relation can be violated and discuss some potential applications of the relation. This relation may be used to confirm the robustness of claimed observations of gravitational lensing of gravitational waves and the subsequent reconstruction of the matter power spectrum.

Keywords: Gravitational lensing, Gravitational waves
Remnant Black Hole Kicks and Implications for Hierarchical Mergers. When binary black holes merge in dense star clusters, their remnants can pair up with other black holes in the cluster, forming heavier and heavier black holes in a process called hierarchical merger. The most important condition for hierarchical merger to occur is that remnants formed by mergers are retained by the host star cluster. Using the publicly available gravitational-wave event database, we infer the magnitudes of kick velocities imparted to the remnant black holes due to anisotropic emission of gravitational waves and use that to quantify the retention probability of each event as a function of the escape speed of the star cluster. Among the second gravitational-wave transient catalog (GWTC-2) events, GW190814 provides the tightest constraint on the kick magnitude with ${V}_{\mathrm{kick}}={74}_{-7}^{+10}$ km s-1 at the 90% credible level. We find that star clusters with escape speeds of 200 km s-1 can retain about 50% of the events in the GWTC-2. Using the escape speed distributions of nuclear star clusters and globular clusters, we find that ~17 (2) remnants of GWTC-2 may be retained by the host star cluster if all GWTC-2 events occurred in nuclear (globular) clusters. Our study demonstrates the importance of folding in kick velocity inferences in future studies of hierarchical mergers.

Keywords: High energy astrophysics, Gravitational waves, Astrophysical black holes, Star clusters
A New Set of Chisels for Galactic Archeology: Sc, V, and Zn as Taggers of Accreted Globular Clusters. Chemical tagging is a powerful tool to reveal the origin of stars and globular clusters (GCs), especially when dynamics alone cannot provide robust answers. So far, mostly α-elements and neutron capture elements have been used to distinguish stars born in the Milky Way (MW) from those born in external environments such as that of dwarf galaxies. Here, instead, we use iron-peak element abundances to investigate the origin of a sample of metal-rich GCs. By homogeneously analyzing high-resolution UVES spectra of giant stars belonging to four metal-rich GCs (namely NGC 5927, NGC 6388, NGC 6441, and NGC 6496), we find that while the α-elements Si and Ca have similar abundance ratios for all four GCs, and Ti and neutron capture elements (La, Ba, and Eu) only show a marginal discrepancy, a stark difference is found when considering the abundances of some iron-peak elements (Sc, V, and Zn). In particular, NGC 6388 and NGC 6441 have abundance ratios for these iron-peak elements significantly lower (by ~0.5 dex) than those measured in NGC 5927 and NGC 6496, which are clearly identified as born in situ MW clusters through an analysis of their orbital properties. These measurements indicate that the environment in which these clusters formed is different, and they provide robust evidence supporting an accreted origin from the same progenitor for NGC 6388 and NGC 6441. * Based on observations collected at the ESO-VLT under programs 073.D-0211, 079.B-0721, and 193.D-0232.

Keywords: Globular star clusters, Stellar abundances
The Remnant and Origin of the Historical Supernova 1181 AD. The guest star of AD 1181 is the only historical supernova of the past millennium that is without a definite counterpart. The previously proposed association with supernova remnant G130.7+3.1 (3C 58) is in strong doubt because of the inferred age of this remnant. Here we report a new identification of SN 1181 with our codiscovery of the hottest known Wolf-Rayet star of the oxygen sequence (IRAS 00500+6713 or 2MASS J00531123+6730023, here named by us as "Parker's star") and its surrounding nebula Pa 30. Our spectroscopy of the nebula shows a fast shock with extreme velocities of ≍1100 km s-1. The derived expansion age of the nebula implies an explosive event ≍1000 yr ago that agrees with the 1181 event. The on-sky location also fits the historical Chinese and Japanese reports of SN 1181 to within 3°5. Pa 30 and Parker's star have previously been proposed to be the result of a double-degenerate merger, leading to a rare Type Iax supernova. The likely historical magnitude and the distance suggest the event was subluminous for normal supernova. This agrees with the proposed Type Iax association that would also be only the second of its kind in the Galaxy. Taken together, the age, location, event magnitude, and duration elevate Pa 30 to prime position as the counterpart of SN 1181. This source is the only Type Iax supernova where detailed studies of the remnant star and nebula are possible. It provides strong observational support for the double-degenerate merger scenario for Type Iax supernovae.

Keywords: Supernova remnants, Wolf-Rayet stars, Supernovae
GRB 200716C: Evidence for a Short Burst Being Lensed. A tiny fraction of observed gamma-ray bursts (GRBs) may be lensed. The time delays induced by the gravitational lensing are milliseconds to seconds if the point lenses are intermediate-mass black holes. The prompt emission of the lensed GRBs, in principle, should have repeated pulses with identical light curves and spectra but different fluxes and slightly offset positions. In this work, we search for such candidates within the GRBs detected by Fermi/GBM, Swift/Burst Alert Telescope, and HXMT/HE and report the identification of an attractive event GRB 200716C that consists of two pulses. Both the autocorrelation analysis and the Bayesian inference of the prompt emission light curve are in favor of the gravitational-lensing scenario. Moreover, the spectral properties of the two pulses are rather similar and follow the so-called Amati relation of short GRBs rather than long-duration bursts. The measured flux ratios between the two pulses are nearly constant in all channels, as expected from gravitational lensing. We therefore suggest that the long-duration burst GRB 200716C was a short event being lensed. The redshifted mass of the lens was estimated to be ${4.25}_{-1.36}^{+2.46}\times {10}^{5}\,{M}_{\odot }$ (90% credibility). If correct, this could point toward the existence of an intermediate-mass black hole along the line of sight of GRB 200716C.

Keywords: Gamma-ray bursts, Gravitational lensing
The Predicament of Absorption-dominated Reionization: Increased Demands on Ionizing Sources. The reionization epoch concludes when ionizing photons reach every corner of the universe. Reionization has generally been assumed to be limited primarily by the rate at which galaxies produce ionizing photons, but the recent measurement of a surprisingly short ionizing photon mean free path of ${0.75}_{-0.45}^{+0.65}$ proper Mpc at z = 6 by Becker et al. suggests that absorption by residual neutral hydrogen in the otherwise ionized intergalactic medium may play a much larger role than previously expected. Here we show that consistency between this short mean free path and the coeval dark pixel fraction in the Lyα forest requires a cumulative output of ${6.1}_{-2.4}^{+11}$ ionizing photons per baryon by reionization's end, well above the typically required ~1-3. This represents a dramatic increase in the ionizing photon budget over previous estimates, greatly exacerbating the tension with measurements of the ionizing output from galaxies at later times. Translating this constraint into the instantaneous ionizing production from galaxies in our model, we find ${\mathrm{log}}_{10}{f}_{\mathrm{esc}}{\xi }_{\mathrm{ion}}/{(\mathrm{erg}/\mathrm{Hz})}^{-1}={25.02}_{-0.21}^{+0.45}$ at z ~ 6. Even with optimistic assumptions about the ionizing production efficiency of early stellar populations, and assuming the galaxy luminosity function extends to extremely faint sources (MUV ≤ - 11), complete reionization requires the escape fraction of ionizing photons to exceed 20% across the galaxy population. This is far larger than observed in any galaxy population at lower redshifts, requiring rapid evolution in galaxy properties after the first billion years of cosmic time. This tension cannot be completely relieved within existing observational constraints on the hydrogen neutral fraction and mean free path.

Keywords: Reionization, High-redshift galaxies, Astronomical simulations, Intergalactic medium
Outward Migration of Super-Jupiters. Recent simulations show that giant planets of about 1 MJ migrate inward at a rate that differs from the type II prediction. Here we show that at higher masses, planets migrate outward. Our result differs from previous ones because of our longer simulation times, lower viscosity, and boundary conditions that allow the disk to reach a viscous steady state. We show that, for planets on circular orbits, the transition from inward to outward migration coincides with the known transition from circular to eccentric disks that occurs for planets more massive than a few Jupiters. In an eccentric disk, the torque on the outer disk weakens due to two effects: the planet launches weaker waves, and those waves travel further before damping. As a result, the torque on the inner disk dominates, and the planet pushes itself outward. Our results suggest that the many super-Jupiters observed by direct imaging at large distances from the star may have gotten there by outward migration.

Keywords: Planetary migration, Protoplanetary disks, Planet formation
APOGEE-2 Discovery of a Large Population of Relatively High-metallicity Globular Cluster Debris. We report the discovery of a new, chemically distinct population of relatively high-metallicity ([Fe/H] &gt; -0.7) red giant stars with super-solar [N/Fe] (≳+0.75) identified within the bulge, disk, and halo of the Milky Way. This sample of stars was observed during the second phase of the Apache Point Observatory Galactic Evolution Experiment (APOGEE-2); the spectra of these stars are part of the seventeenth Data Release (DR 17) of the Sloan Digital Sky Survey. We hypothesize that this newly identified population was formed in a variety of progenitors, and is likely made up of either fully or partially destroyed metal-rich globular clusters, which we refer to as globular cluster debris (GCD), identified by their unusual photospheric nitrogen abundances. It is likely that some of the GCD stars were probable members of the Gaia-Enceladus-Sausage accretion event, along with clusters formed in situ.

Keywords: Globular star clusters, Stellar abundances, Red giant stars
Impact of Natal Kicks on Merger Rates and Spin-Orbit Misalignments of Black Hole-Neutron Star Mergers. The long wait for the detection of merging black hole-neutron star (BH-NS) binaries is finally over with the announcement by the LIGO/Virgo/Kagra collaboration of GW200105 and GW200115. Remarkably, the primary of GW200115 has a negative spin projection onto the orbital angular momentum, with about 90% probability. Merging BH-NS binaries are expected to form mainly through the evolution of massive binary stars in the field, since their dynamical formation in dense star clusters is strongly suppressed by mass segregation. In this Letter, we carry out a systematic statistical study of the binary stars that evolve to form a BH-NS binary, considering different metallicities and taking into account the uncertainties on the natal-kick distributions for BHs and NSs and on the common-envelope phase of binary evolution. Under the assumption that the initial stellar spins are aligned with the binary angular momentum, we show that both large natal kicks for NSs (≳150 km s-1) and high efficiencies for common-envelope ejection are required to simultaneously explain the inferred high merger rates and the large spin-orbit misalignment of GW200115.

Keywords: Neutron stars, Black hole spin-flip, Gravitational wave detectors, Black holes, Stellar mass black holes, Gravitational wave sources, Gravitational wave astronomy, Gravitational waves, Astrophysical black holes
A New Gamma-Ray-emitting Population of FR0 Radio Galaxies. The enigmatic class of Fanaroff-Riley type 0 (FR0) radio galaxies is emerging as the missing link between the faint yet numerous population of compact radio sources in nearby galaxies and the canonical Fanaroff-Riley classification scheme. This Letter reports the first γ-ray identification of three FR0 galaxies above 1 GeV using more than a decade of the Fermi Large Area Telescope observations. A cumulative γ-ray emission at &gt;5σ significance was also detected from the γ-ray unresolved FR0 sources using the stacking technique, suggesting the FR0 population to be a γ-ray emitter as a whole. The multifrequency properties of the γ-ray-detected sources are similar to other FR0s, thus indicating the high-energy radiation to originate from misaligned jets. Given their large abundance, FR0 radio galaxies are proposed as plausible candidates for IceCube-detected neutrinos and the results presented in this Letter may provide crucial constraints on their γ-ray production mechanism and the origin of cosmic neutrinos.

Keywords: Extragalactic astronomy, Gamma-ray astronomy, Relativistic jets
Stephan Prantner's Sunspot Observations during the Dalton Minimum. In addition to regular Schwabe cycles (≈11 yr), solar variability also shows longer periods of enhanced or reduced activity. Of these, reconstructions of the Dalton Minimum provide controversial sunspot group numbers and limited sunspot positions, partially due to limited source record accessibility. In this context, we analyzed Stephan Prantner's sunspot observations spanning from 1804 to 1844, the values of which had only been known through estimates despite their notable chronological coverage during the Dalton Minimum. We identified his original manuscript in Stiftsarchiv Wilten, near Innsbruck (Austria). We reviewed his biography (1782-1873) and located his observational sites at Wilten and Waidring, which housed the principal telescopes for his early and late observations: a 3.5 inch astronomical telescope and a Reichenbach 4 foot achromatic erecting telescope, respectively. We identified 215 days of datable sunspot observations, which is almost twice as much data as his estimated data in the existing databases (=115 days). In Prantner's records, we counted up to seven to nine sunspot groups per day and measured sunspot positions, which show their distributions in both solar hemispheres. These results strikingly emphasize the difference between the Dalton Minimum and the Maunder Minimum as well as the similarity between the Dalton Minimum and the weak solar cycles in the modern observations.

Keywords: Sunspot groups, Sunspots, Maunder minimum, Solar-terrestrial interactions, Sunspot cycle
The Impacts of Modeling Choices on the Inference of Circumgalactic Medium Properties from Sunyaev-Zeldovich Observations. As the signal-to-noise of Sunyaev-Zeldovich (SZ) cross-correlation measurements of galaxies improves our ability to infer properties about the circumgalactic medium (CGM), we will transition from being limited by statistical uncertainties to systematic uncertainties. Using thermodynamic profiles of the CGM created from the IllustrisTNG (The Next Generation) simulations we investigate the importance of specific choices in modeling the galaxy sample. These choices include different sample selections in the simulation (stellar versus halo mass, color selections) and different fitting models (matching by the shape of the mass distribution, inclusion of a two-halo term). We forward model a mock galaxy sample into projected SZ observable profiles and fit these profiles to a generalized Navarro-Frenk-White profile using forecasted errors of the upcoming Simons Observatory experiment. We test the number of free parameters in the fits and show that this is another modeling choice that yields different results. Finally, we show how different fitting models can reproduce parameters of a fiducial profile, and show that the addition of a two-halo term and matching by the mass distribution of the sample are extremely important modeling choices to consider.

Keywords: Sunyaev-Zeldovich effect, Circumgalactic medium
TRAO Survey of the Nearby Filamentary Molecular Clouds, the Universal Nursery of Stars (TRAO FUNS). II. Filaments and Dense Cores in IC 5146. We present the results on the physical properties of filaments and dense cores in IC 5146, as a part of the TRAO FUNS project. We carried out on-the-fly mapping observations using the Taeduk Radio Astronomy Observatory (TRAO) 14 m telescope covering about 1 square degree of the area of IC 5146 using various molecular lines. We identified 14 filaments (24 in total, including sub-filaments) from the C18O (1-0) data cube and 22 dense cores from the N2H+ (1-0) data. We examined the filaments' gravitational criticality, turbulence properties, accretion rate from filaments to dense cores, and relative evolutionary stages of cores. Most filaments in IC 5146 are gravitationally supercritical within the uncertainty, and most dense cores are formed in them. We found that dense cores in the hubs show a systemic velocity shift of ~0.3 km s-1 between the N2H+ and C18O gas. Besides, these cores are subsonic or transonic, while the surrounding filament gas is transonic or supersonic, indicating that the cores in the hubs are likely formed by the dissipation of turbulence in the colliding turbulent filaments and the merging is still ongoing. We estimated a mass accretion rate of 15-35 M⊙ Myr-1 from the filaments to the dense cores, and the required timescales to collect the current core mass are consistent with the lifetime of the dense cores. The structures of filaments and dense cores in the hub can form from a collision of turbulent converging flows, and mass flow along the filaments to the dense cores may play an important role in forming dense cores.

Keywords: Star formation, Interstellar filaments, Interstellar medium, Molecular clouds
Propionamide (C<SUB>2</SUB>H<SUB>5</SUB>CONH<SUB>2</SUB>): The Largest Peptide-like Molecule in Space. Peptide bonds, as the molecular bridges that connect amino acids, are crucial to the formation of proteins. Searches and studies of molecules with embedded peptide-like bonds are thus important for the understanding of protein formation in space. Here we report the first tentative detection of propionamide (C2H5CONH2), the largest peptide-like molecule detected in space toward Sagittarius B2(N1) at a position called N1E that is slightly offset from the continuum peak. New laboratory measurements of the propionamide spectrum were carried out in the 9-461 GHz range, which provide good opportunity to check directly for the transition frequencies of detected interstellar lines of propionamide. Our observing result indicates that propionamide emission comes from the warm, compact cores in Sagittarius B2, in which massive protostellars are forming. The column density of propionamide toward Sgr B2(N1E) was derived to be 1.5 × 1016 cm-2, which is three-fifths of that of acetamide, and one-nineteenth of that of formamide. This detection suggests that large peptide-like molecules can form and survive during star-forming process and may form more complex molecules in the interstellar medium (ISM). The detection of propionamide bodes well for the presence of polypeptides, as well as other complex prebiotic molecules in the ISM.

Keywords: Spectral line identification, Spectroscopy, Astrochemistry
Resolved Neutral Outflow from a Lensed Dusty Star-forming Galaxy at z = 2.09. We report the detection of a massive neutral gas outflow in the z = 2.09 gravitationally lensed dusty star-forming galaxy HATLAS J085358.9+015537 (G09v1.40), seen in absorption with the OH+(11-10) transition using spatially resolved (0"5 × 0"4) Atacama Large Millimeter/submillimeter Array (ALMA) observations. The blueshifted OH+ line is observed simultaneously with the CO(9-8) emission line and underlying dust continuum. These data are complemented by high-angular-resolution (0"17 × 0"13) ALMA observations of CH+(1-0) and underlying dust continuum, and Keck 2.2 μm imaging tracing the stellar emission. The neutral outflow, dust, dense molecular gas, and stars all show spatial offsets from each other. The total atomic gas mass of the observed outflow is 6.7 × 109M☉, &gt;25% as massive as the gas mass of the galaxy. We find that a conical outflow geometry best describes the OH+ kinematics and morphology and derive deprojected outflow properties as functions of possible inclination (0°38-64°). The neutral gas mass outflow rate is between 83 and 25,400 M☉ yr-1, exceeding the star formation rate (788 ± 300 M☉ yr-1) if the inclination is &gt;3°6 (mass-loading factor = 0.3-4.7). Kinetic energy and momentum fluxes span (4.4-290) × 109 L☉ and (0.1-3.7) × 1037 dyne, respectively (energy-loading factor = 0.013-16), indicating that the feedback mechanisms required to drive the outflow depend on the inclination assumed. We derive a gas depletion time between 29 and 1 Myr, but find that the neutral outflow is likely to remain bound to the galaxy unless the inclination is small and may be reaccreted if additional feedback processes do not occur.

Keywords: Starburst galaxies, Strong gravitational lensing, Interstellar absorption, Galaxy evolution, High-redshift galaxies, Galaxy processes