adsabs/SciX_UAT_keywords huggingface dataset:
Formation and Evolution of Ultraluminous X-Ray Pulsar Binaries to Pulsar-Neutron Star and Pulsar-White Dwarf Systems

Recent observational and theoretical results have suggested that some of ultraluminous X-ray (ULX) sources may contain neutron star (NS) accretors. However, the formation channel and properties of donor stars of NS ULXs remain uncertain. By adopting the nonconservative and rotation-dependent mass transfer model in the primordial binary evolution, we investigate the way to form pulsar ULXs like observed pulsar ULXs in a systematic way. Our simulation results indicate that pulsar ULXs with Be stars and intermediate or/and high-mass donors match observed apparent luminosities, orbital periods, and observationally indicated donor masses of known pulsar ULXs. ULXs with Be and intermediate donors are main contributors. The route of accretion-induced collapse of WDs has a 4.5% contribution to the NS ULXs, 4.0% of NSs in ULXs are formed through electron-capture supernovae (SNe), and 91.5% of NSs in ULXs are born with core-collapse SNe. We also studied the evolution of pulsar ULXs to double compact star systems. We do not find NS-black hole systems (merging in a Hubble time) that evolved from pulsar ULXs. Pulsar-white dwarf (WD) cases that evolve through pulsar ULXs have significant contributions to the whole NS-WD gravitational wave sources. Contributions of pulsar-WD and pulsar-NS cases that experienced pulsar ULXs are ∼40% and 11% among all LISA NS-WD and NS-NS sources, respectively. Monte Carlo simulation noise with different models give a nonnegligible uncertainty.

Keywords: binary stars; close binary stars; x-ray binary stars; pulsars; gravitational wave sources; white dwarf stars; compact objects
The Effect of Ultraviolet Photon Pumping of H2 in Dust-deficient Protoplanetary Disks

We perform radiation hydrodynamics simulations to study the structure and evolution of a photoevaporating protoplanetary disk. Ultraviolet and X-ray radiation from the host star heats the disk surface, where H2 pumping also operates efficiently. We run a set of simulations in which we varied the number of dust grains or the dust-to-gas mass ratio, which determines the relative importance between photoelectric heating and H2 pumping. We show that H2 pumping and X-ray heating contribute more strongly to the mass loss of the disk when the dust-to-gas mass ratio is ${ \mathcal D }\leqslant {10}^{-3}$ . The disk mass-loss rate decreases with a lower dust amount, but remains around 10‑10‑11 M ⊙yr‑1. In these dust-deficient disks, H2 pumping enhances photoevaporation from the inner disk region and shapes the disk mass-loss profile. We thus argue that the late-stage disk evolution is affected by the ultraviolet H2 pumping effect. The mass-loss rates derived from our simulations can be used in the study of long-term disk evolution.

Keywords: protoplanetary disks; planet formation; hydrodynamical simulations; star formation; interstellar medium
Velocity Difference of Ions and Neutrals in Solar Prominences

Marked velocity excesses of ions relative to neutrals are obtained from two time series of the neighboring emission lines He I 5015 Å and Fe II 5018 Å in a quiescent prominence. Their Doppler shifts show time variations of quasi-periodic character where the ions are faster than the neutrals, 1.0 ≤ Vmacro(Fe II)/Vmacro(He I) ≤ 1.35 in series A and ≤1.25 in series B. This "ratio excess" confirms our earlier findings of a 1.22 ion velocity excess, but the present study shows a restriction in space and time of typically 5 Mm and 5 minutes. The ratio excess is superposed by a time- and velocity-independent "difference excess" of -0.3 ≤ Vmacro(Fe II)-Vmacro(He I) ≤ +0.7 km s-1 in series A (also indicated in series B). The high repetition rate of 3.9 s enables the detection of high-frequency oscillations with several damped 22 s periods in series A. These show a ratio excess with a maximum of 1.7. We confirm the absence of a significant phase delay of He neutrals with respect to the Fe ions.

Keywords: solar prominences
Void Replenishment: How Voids Accrete Matter Over Cosmic History

Cosmic voids are underdense regions filling up most of the volume in the universe. They are expected to emerge in regions comprising negative initial density fluctuations, and subsequently expand as the matter around them collapses and forms walls, filaments, and clusters. We report results from the analysis of a cosmological simulation specially designed to accurately describe low-density regions, such as cosmic voids. Contrary to the common expectation, we find that voids also experience significant mass inflows over cosmic history. On average, 10% of the mass of voids in the sample at z ~ 0 is accreted from overdense regions, reaching values beyond 35% for a significant fraction of voids. More than half of the mass entering the voids lingers on periods of time ~10 Gyr well inside them, reaching inner radii. This would imply that part of the gas lying inside voids at a given time proceeds from overdense regions (e.g., clusters or filaments), where it could have been preprocessed, thus challenging the scenario of galaxy formation in voids, and dissenting from the idea of them being pristine environments.

Keywords: large-scale structure of the universe; voids; accretion; galaxy environments; computational astronomy
Bombardment of Lunar Polar Crater Interiors by Out-of-ecliptic Ions: ARTEMIS Observations

Permanently shadowed regions (PSRs) inside lunar polar craters likely harbor volatiles which are of great interest for both science and resource utilization. The origin and evolution of this resource is in part driven by external space weathering, including the bombardment by space plasma ions. Previous work has investigated the flux of horizontal solar wind ions that are deflected into lunar polar craters by plasma wake electrostatic fields. Here, we constrain the flux of ions that travel northward or southward in the natural environment encountered by the Moon along its orbit. Using 9 years of in situ ion measurements gathered by the ARTEMIS mission, we find that all locations inside lunar craters are altered by a flux of out-of-ecliptic ions of 10-3 times the solar wind flux. In particular, the central floor of Shackleton's crater is weathered by a non-null ion flux. The origin of northward and southward ions impacting the Moon is identified as (i) shocked thermalized solar wind ions in the terrestrial magnetosheath and (ii) the isotropic component of ion distributions in the terrestrial magnetotail. The energy spectrum of out-of-ecliptic ions is found to be flatter than the solar wind spectrum. Thus, sputtering of pure water ice irradiated by out-of-ecliptic ions would be created for more than 30% by >3 keV protons, unlike equatorial locations that are mostly sputtered by 1 keV protons. Future work may investigate the influence of the low, but nonzero flux of out-of-ecliptic ions reported here on the budget of volatiles in lunar PSRs.

Keywords: the moon; solar wind; planetary magnetospheres
A Pan-STARRS1 Search for Planet Nine

We present a search for Planet Nine using the second data release of the Pan-STARRS1 survey. We rule out the existence of a Planet Nine with the characteristics of that predicted in Brown & Batygin to a 50% completion depth of V = 21.5. This survey, along with previous analyses of the Zwicky Transient Facility and Dark Energy Survey data, rules out 78% of the Brown & Batygin parameter space. Much of the remaining parameter space is at V > 21 in regions near and in the area where the northern galactic plane crosses the ecliptic.

Keywords: sky surveys; solar system gas giant planets
Spatially Resolved Moving Radio Burst Associated with an EUV Wave

Coronal mass ejections (CMEs) are large clouds of magnetized plasma ejected from the Sun and are often associated with the acceleration of electrons that can result in radio emission via various mechanisms. However, the underlying mechanism relating the CMEs and particle acceleration still remains a subject of heated debate. Here, we report multi-instrument radio and extreme ultraviolet (EUV) imaging of a solar eruption event on 2011 September 24. We determine the emission mechanism of a moving radio burst, identify its three-dimensional location with respect to a rapidly expanding EUV wave, and find evidence for CME shocks that produce quasiperiodic acceleration of electron beams.

Keywords: solar particle emission; solar coronal mass ejections; radio bursts
Planetesimal Initial Mass Functions Following Diffusion-regulated Gravitational Collapse

The initial mass function (IMF) of planetesimals is of key importance for understanding the initial stages of planet formation, yet theoretical predictions so far have been insufficient in explaining the variety of IMFs found in simulations. Here, we connect diffusion-tidal-shear limited planetesimal formation within the framework of a Toomre-like instability in the particle midplane of a protoplanetary disk to an analytic prediction for the planetesimal IMF. The shape of the IMF is set by the stability parameter Q p, which in turn depends on the particle Stokes number, the Toomre Q value of the gas, the local dust concentration, and the local diffusivity. We compare our prediction to high-resolution numerical simulations of the streaming instability and planetesimal formation via gravitational collapse. We find that our IMF prediction agrees with numerical results and is consistent with both the paradigm that planetesimals are born big and the power-law description commonly found in simulations.

Keywords: planetesimals; protoplanetary disks; astrophysical fluid dynamics
Weak-lensing Analysis of the Complex Cluster Merger A746 with Subaru/Hyper Suprime-Cam

The galaxy cluster A746 (z = 0.214), featuring a double radio relic system, two isolated radio relics, a possible radio halo, disturbed V-shaped X-ray emission, and intricate galaxy distributions, is a unique and complex merging system. We present a weak-lensing analysis of A746 based on wide-field imaging data from Subaru/Hyper Suprime-Cam observations. The mass distribution is characterized by a main peak, which coincides with the center of the X-ray emission. At this main peak, we detect two extensions toward the north and west tracing the cluster galaxy and X-ray distributions. Despite the ongoing merger, our estimate of the A746 global mass M 500 = 4.4 ± 1.0 × 1014 M ⊙ is consistent with the previous results from Sunyaev-Zel'dovich and X-ray observations. We conclude that reconciling the distributions of mass, galaxies, and intracluster medium with the double radio relic system and other radio features remains challenging.

Keywords: abell clusters; galaxy clusters; weak gravitational lensing
High Metal Content of Highly Accreting Quasars

We present an analysis of UV spectra of 13 quasars believed to belong to extreme Population A (xA) quasars, aimed at the estimation of the chemical abundances of the broad-line-emitting gas. Metallicity estimates for the broad-line-emitting gas of quasars are subject to a number of caveats; xA sources with the strongest Fe II emission offer several advantages with respect to the quasar general population, as their optical and UV emission lines can be interpreted as the sum of a low-ionization component roughly at quasar rest frame (from virialized gas), plus a blueshifted excess (a disk wind), in different physical conditions. Capitalizing on these results, we analyze the component at rest frame and the blueshifted one, exploiting the dependence of several intensity line ratios on metallicity Z. We find that the validity of intensity line ratios as metallicity indicators depends on the physical conditions. We apply the measured diagnostic ratios to estimate the physical properties of sources such as density, ionization, and metallicity of the gas. Our results confirm that the two regions (the low-ionization component and the blueshifted excess) of different dynamical conditions also show different physical conditions and suggest metallicity values that are high, and probably the highest along the quasar main sequence, with Z ∼ 20-50 Z⊙, if the solar abundance ratios can be assumed constant. We found some evidence of an overabundance of aluminum with respect to carbon, possibly due to selective enrichment of the broad-line-emitting gas by supernova ejecta.

Keywords: quasars; active galactic nuclei; radio quiet quasars
On the Polarized Absorption Lines in Gamma-Ray Burst Optical Afterglows

Spectropolarimetric measurements of gamma-ray burst (GRB) optical afterglows contain polarization information for both continuum and absorption lines. Based on the Zeeman effect, an absorption line in a strong magnetic field is polarized and split into a triplet. In this paper, we solve the polarization radiative transfer equations of the absorption lines, and obtain the degree of linear polarization of the absorption lines as a function of the optical depth. In order to effectively measure the degree of linear polarization for the absorption lines, a magnetic field strength of at least 103 G is required. The metal elements that produce the polarized absorption lines should be sufficiently abundant and have large oscillation strengths or Einstein absorption coefficients. We encourage both polarization measurements and high-dispersion observations of the absorption lines in order to detect the triplet structure in early GRB optical afterglows.

Keywords: gamma-ray bursts
Molecular Chemistry for Dark Matter. II. Recombination, Molecule Formation, and Halo Mass Function in Atomic Dark Matter

Dissipative dark matter predicts rich observable phenomena that can be tested with future large-scale structure surveys. As a specific example, we study atomic dark matter, consisting of a heavy particle and a light particle charged under a dark electromagnetism. In particular, we calculate the cosmological evolution of atomic dark matter focusing on dark recombination and dark molecule formation. We have obtained the relevant interaction rate coefficients by rescaling the rates for normal hydrogen, and evolved the abundances for ionized, atomic, and molecular states using a modified version of Recfast++ (which we have released publicly at a a https://github.com/jamesgurian/RecfastJulia ). We also provide an analytical approximation for the final abundances. We then calculate the effects of atomic dark matter on the linear power spectrum, which enter through a dark photon diffusion and dark acoustic oscillations. At formation time, the atomic dark matter model suppresses halo abundances on scales smaller than the diffusion scale, just as warm dark matter models suppress the abundance below the free-streaming scale. The subsequent evolution with radiative cooling, however, will alter the halo mass function further.

Keywords: cosmology; dark matter; molecular physics; recombination (cosmology)
Sensitivity of Cosmological Parameter Estimation to Nonlinear Prescription from Cosmic Shear

Several ongoing and upcoming large-scale structure surveys aim to explore the nonlinear regime of structure formation with high precision. Making reliable cosmological inferences from these observations necessitates precise theoretical modeling of the mildly nonlinear regime. In this work we explore how the choice of nonlinear prescription would impact parameter estimation from cosmic shear measurements for a Euclid-like survey. Specifically, we employ two different nonlinear prescriptions of halofit and the Effective Field Theory of the Large Scale Structure and compare their measurements for the three different cosmological scenarios of ΛCDM, wCDM, and (w 0, w a ) CDM. We also investigate the impact of different nonlinear cutoff schemes on parameter estimation. We find that the predicted errors on most parameters shrink considerably as smaller scales are included in the analysis, with the amount depending on the nonlinear prescription and the cutoff scheme used. We use predictions from the halofit model to analyze the mock data from DarkSky N-body simulations and quantify the parameter bias introduced in the measurements due to the choice of nonlinear prescription. We observe that σ 8 and n s have the largest measurement bias induced by inaccuracies of the halofit model.

Keywords: cosmology; large-scale structure of the universe; observational cosmology; astronomy data analysis; weak gravitational lensing
The Intriguing Parsec-scale Radio Structure in the "Offset AGN" KISSR 102

We report the detection of an intriguing parsec-scale radio source in the "offset AGN" candidate, KISSR 102. The elliptical host galaxy includes two optical nuclei at a projected separation of 1.54 kpc, N1 and N2, to the southeast and northwest, respectively. Phase-referenced Very Long Baseline Array observations at 1.5 and 4.9 GHz of this low ionization nuclear emission line region galaxy have detected double radio components (A and B) at a projected separation of 4.8 parsec at 1.5 GHz, and another partially resolved double radio structure at 4.9 GHz coincident with the brighter radio component A. These radio detections are confined to the optical nucleus N1. The brightness temperatures of all the detected radio components are high, ≳108 K, consistent with them being components of a radio active galactic nucleus (AGN). The 1.5-4.9 GHz spectral index is inverted (α ∼ + 0.64 ± 0.08) for component A and steep for component B (α ≲ -1.6). The dramatic change in the spectral indices of A and B is inconsistent with it being a typical "core-jet" structure from a single AGN, or the mini-lobes of a compact symmetric object. To be consistent with a "core-jet" structure, the jet in KISSR 102 would need to be undergoing strong jet-medium interaction with dense surrounding media resulting in a drastic spectral steepening of the jet. Alternatively, the results could be consistent with the presence of a parsec-scale binary radio AGN, which is the end result of a three-body interaction involving three supermassive black holes in the center of KISSR 102.

Keywords: seyfert galaxies; very long baseline interferometry; emission line galaxies; radio continuum emission; liner galaxies; black holes; galaxy mergers
Magnetic Outbreak Associated with Exploding Granulations

Diagnosing the spatiotemporal pattern of magnetic flux on the Sun is vital for understanding the origin of solar magnetism and activity. Here, we report a new form of flux appearance, magnetic outbreak, using observations with an extremely high spatial resolution of 0.″16 from the 1.6 m Goode Solar Telescope at the Big Bear Solar Observatory. Magnetic outbreak refers to an early growth of unipolar magnetic flux and its later explosion into fragments, in association with plasma upflow and exploding granulations; each individual fragment has flux of 1016-1017 Mx, moving apart with a velocity of 0.5-2.2 km s-1. The magnetic outbreak takes place in the hecto-Gauss region of pore moats. In this study, we identify six events of magnetic outbreak during 6 hr observations over an approximately 40″ × 40″ field of view. The newly discovered magnetic outbreak might be the first evidence of the long-anticipated convective blowup.

Keywords: solar magnetic fields; solar photosphere; solar granulation; solar activity
The Baryonic Tully-Fisher Relation in the Local Group and the Equivalent Circular Velocity of Pressure-supported Dwarfs

We explore the baryonic Tully-Fisher relation in the Local Group. Rotationally-supported Local Group galaxies adhere precisely to the relation defined by more distant galaxies. For pressure-supported dwarf galaxies, we determine the scaling factor βc that relates their observed velocity dispersion to the equivalent circular velocity of rotationally-supported galaxies of the same mass such that Vo = βcσ*. For a typical mass-to-light ratio Υ* = 2 M⊙/L⊙ in the V band, we find that βc = 2. More generally, $\mathrm{log}{\beta }_{c}=0.25\mathrm{log}{{\rm{\Upsilon }}}_{* }+0.226$ . This provides a common kinematic scale relating pressure and rotationally-supported dwarf galaxies.

Keywords: galaxies; local group; orbital motion; scaling relations
Chemical Diagnostics to Unveil Environments Enriched by First Stars

Unveiling the chemical fingerprints of the first (Population III, hereafter Pop III) stars is crucial for indirectly studying their properties and probing their massive nature. In particular, very massive Pop III stars explode as energetic pair-instability supernovae (PISNe), allowing their chemical products to escape in the diffuse medium around galaxies, opening the possibility to observe their fingerprints in distant gas clouds. Recently, three z > 6.3 absorbers with abundances consistent with an enrichment from PISNe have been observed with JWST. In this Letter, we present novel chemical diagnostics to uncover environments mainly imprinted by PISNe. Furthermore, we revise the JWST low-resolution measurements by analyzing the publicly available high-resolution X-Shooter spectra for two of these systems. Our results reconcile the chemical abundances of these absorbers with those from literature, which are found to be consistent with an enrichment dominated (>50% metals) by normal Pop II SNe. We show the power of our novel diagnostics in isolating environments uniquely enriched by PISNe from those mainly polluted by other Pop III and Pop II SNe. When the subsequent enrichment from Pop II SNe is included, however, we find that the abundances of PISN-dominated environments partially overlap with those predominantly enriched by other Pop III and Pop II SNe. We dub these areas confusion regions. Yet, the odd–even abundance ratios [Mg,Si/Al] are extremely effective in pinpointing PISN-dominated environments and allowed us to uncover, for the first time, an absorber consistent with a combined enrichment by a PISN and another Pop III SN for all the six measured elements.

Keywords: chemical abundances; abundance ratios; population iii stars
Observations of Titan's Stratosphere during Northern Summer: Temperatures, CH3CN and CH3D Abundances

Titan's atmospheric composition and dynamical state have previously been studied over numerous epochs by both ground- and space-based facilities. However, stratospheric measurements remain sparse during Titan's northern summer and fall. The lack of seasonal symmetry in observations of Titan's temperature field and chemical abundances raises questions about the nature of the middle atmosphere's meridional circulation and evolution over Titan's 29 yr seasonal cycle that can only be answered through long-term monitoring campaigns. Here, we present maps of Titan's stratospheric temperature, acetonitrile (or methyl cyanide; CH3CN) abundance, and monodeuterated methane (CH3D) abundance following Titan's northern summer solstice obtained with Band 9 (∼0.43 mm) Atacama Large Millimeter/submillimeter Array observations. We find that increasing temperatures toward high southern latitudes, currently in winter, resemble those observed during Titan's northern winter by the Cassini mission. Acetonitrile abundances have changed significantly since previous (sub)millimeter observations, and we find that the species is now highly concentrated at high southern latitudes. The stratospheric CH3D content is found to range between 4 and 8 ppm in these observations, and we infer the CH4 abundance to vary between ∼0.9% and 1.6% through conversion with previously measured D/H values. A global value of CH4 = 1.15% was retrieved, lending further evidence to the temporal and spatial variability of Titan's stratospheric methane when compared with previous measurements. Additional observations are required to determine the cause and magnitude of stratospheric enhancements in methane during these poorly understood seasons on Titan.

Keywords: titan; saturnian satellites; planetary atmospheres; planetary science; atmospheric composition; atmospheric variability; submillimeter astronomy; radio astronomy; radiative transfer