adsabs/SciX_UAT_keywords huggingface dataset:
A Search for Coincident Neutrino Emission from Fast Radio Bursts with Seven Years of IceCube Cascade Events

This paper presents the results of a search for neutrinos that are spatially and temporally coincident with 22 unique, nonrepeating fast radio bursts (FRBs) and one repeating FRB (FRB 121102). FRBs are a rapidly growing class of Galactic and extragalactic astrophysical objects that are considered a potential source of high-energy neutrinos. The IceCube Neutrino Observatory's previous FRB analyses have solely used track events. This search utilizes seven years of IceCube cascade events which are statistically independent of track events. This event selection allows probing of a longer range of extended timescales due to the low background rate. No statistically significant clustering of neutrinos was observed. Upper limits are set on the time-integrated neutrino flux emitted by FRBs for a range of extended time windows.

Keywords: neutrino astronomy; radio transient sources; high energy astrophysics
An Analytical Theory for the Growth from Planetesimals to Planets by Polydisperse Pebble Accretion

Pebble accretion is recognized as a significant accelerator of planet formation. Yet only formulae for single-sized (monodisperse) distribution have been derived in the literature. These can lead to significant underestimates for Bondi accretion, for which the best accreted pebble size may not be the one that dominates the mass distribution. We derive in this paper the polydisperse theory of pebble accretion. We consider a power-law distribution in pebble radius, and we find the resulting surface and volume number density distribution functions. We derive also the exact monodisperse analytical pebble accretion rate for which 3D accretion and 2D accretion are limits. In addition, we find analytical solutions to the polydisperse 2D Hill and 3D Bondi limits. We integrate the polydisperse pebble accretion numerically for the MRN distribution, finding a slight decrease (by an exact factor 3/7) in the Hill regime compared to the monodisperse case. In contrast, in the Bondi regime, we find accretion rates 1-2 orders of magnitude higher compared to monodisperse, also extending the onset of pebble accretion to 1-2 orders of magnitude lower in mass. We find megayear timescales, within the disk lifetime, for Bondi accretion on top of planetary seeds of masses 10-6 to 10-4 M ⊕, over a significant range of the parameter space. This mass range overlaps with the high-mass end of the planetesimal initial mass function, and thus pebble accretion is possible directly following formation by streaming instability. This alleviates the need for mutual planetesimal collisions as a major contribution to planetary growth.

Keywords: planet formation; planetary system formation
A Spatially Resolved Survey of Distant Quasar Host Galaxies. I. Dynamics of Galactic Outflows

We present observations of ionized gas outflows in 11 z = 1.39-2.59 radio-loud quasar host galaxies. Data were taken with the integral field spectrograph OSIRIS and the adaptive optics system at the W.M. Keck Observatory targeting nebular emission lines (Hβ, [O III], Hα, [N II], and [S II]) redshifted into the near-infrared (1-2.4 μm). Outflows with velocities of 500-1700 km s-1 are detected in 10 systems on scales ranging from <1 kpc to 10 kpc with outflow rates from 8-2400 M⊙ yr-1 . For five sources, the outflow momentum rates are 4-80 times LAGN/c, consistent with outflows being driven by an energy-conserving shock. The five other outflows are either driven by radiation pressure or an isothermal shock. The outflows are the dominant source of gas depletion, and we find no evidence for star formation along the outflow paths. For eight objects, the outflow paths are consistent with the orientation of the jets. Yet, given the calculated pressures, we find no evidence of the jets currently doing work on these galactic-scale ionized outflows. We find that galactic-scale feedback occurs well before galaxies establish a substantial fraction of their stellar mass, as expected from local scaling relationships.

Keywords: agn host galaxies; galaxy evolution; quasars; radio loud quasars; supermassive black holes; emission line galaxies
GRB 080503: A Very Early Blue Kilonova and an Adjacent Nonthermal Radiation Component

The temporal behavior of the very dim optical afterglow of GRB 080503 is at odds with the regular forward shock afterglow model and a sole kilonova component responsible for optical emission has been speculated in some literature. Here we analyze the optical afterglow data available in archive and construct time-resolved spectra. The significant detection by Keck I in G/R bands at t ~ 3 days, which has not been reported before, as well as the simultaneous Gemini-North r-band measurement, are in favor of a power-law spectrum that is well consistent with the optical to X-ray spectrum measured at t ~ 4.5 days. However, for t ≤ 2 days, the spectrum is thermal-like and a straightforward interpretation is a kilonova emission from a neutron star merger, making it, possibly, the first detection of a very early kilonova signal at t ~ 0.05 day. A nonthermal nature of optical emission at late times (t ~ 2 days), anyhow, cannot be ruled out because of the large uncertainty of the g-band data. We also propose to classify the neutron star merger induced optical transients, according to the temporal behaviors of the kilonova and the nonthermal afterglow emission, into four types. GRB 080503 would then represent the first observation of a subgroup of neutron star merger driven optical transients (i.e., type IV) consisting of an early blue kilonova and an adjacent nonthermal afterglow radiation.

Keywords: high energy astrophysics; gamma-ray bursts
Prediction of Astrometric-microlensing Events from Gaia eDR3 Proper Motions

Astrometric microlensing is a unique tool to measure stellar masses. It allows us to determine the mass of the lensing star with an accuracy of a few percent. In this paper, we update, extend, and refine our predictions of astrometric-microlensing events based on Gaia's early Data release 3 (eDR3). We selected about 500.000 high-proper-motion stars from Gaia eDR3 with μ tot > 100 mas yr-1 and searched for background sources close to their paths. We applied various selection criteria and cuts in order to exclude spurious sources and co-moving stars. By forecasting the future positions of lens and source, we determined epoch of and angular separation at closest approach, and determined an expected positional shift and magnification. Using Gaia eDR3, we predict 1758 new microlensing events with expected shifts larger than 0.1 mas between the epochs J2010.5 and mid J2066.0. Further, we provide more precise information on the angular separation at closest approach for 3084 previously predicted events. This helps to select better targets for observations, especially for events that occur within the next decade. Our search lead to the new prediction of an interesting astrometric-microlensing event by the white dwarf Gaia eDR3-4053455379420641152. In 2025 it will pass by a G = 20.25 mag star, which will lead to a positional shift of the major image of $\delta {\theta }_{+}={1.2}_{-0.5}^{+2.0}\,\mathrm{mas}$ . Since the background source is only ΔG = 2.45 mag fainter than the lens, also the shift of the combined center of light will be measurable, especially using a near-infrared filter, where the background star is brighter than the lens (ΔKs = -1.1 mag). *The results of the predicted microlensing events is available in electronic form via the GAVO Data Center https://dc.g-vo.org/amlensing/q3/q/form. †The source code for this study is made publicly available https://github.com/jkluter/amlensing.

Keywords: astrometry; proper motions; catalogs; astrometric microlensing effect; stellar masses; white dwarf stars
Effects of Airless Bodies' Regolith Structures and of the Solar Wind's Properties on the Backscattered Energetic Neutral Atoms Flux

The surfaces of airless planetary bodies, such as the Moon or Mercury, are covered with regoliths, which interact with the solar wind. The solar protons can either be absorbed by the surface or neutralized and reflected as hydrogen energetic neutral atoms (ENAs). The ENA flux is thought to depend mostly on the structure of the upper regolith layer. By using a model combining a Monte Carlo approach to describe a solar proton's journey through the lunar surface with molecular dynamics to characterize its interactions with the regolith's grains, we highlight the surface roughness as a key parameter that influences the backscattered H ENA flux. By considering spherical silica grains, the lunar regolith's structure is described using the open-source code Large-scale Atomic/Molecular Massively Parallel Simulator (or LAMMPS), which allows a realistic description of grain-on-grain contacts. The roughness of the modeled regolith, characterized by the roughness ratio, is shown to be dictated by the surface energy and the grain-size distribution. This work shows that a rougher surface favors deeper penetration of the protons inside the regolith, which increases the number of collisions and thus decreases their reflected fraction. The angular distribution of the backscattered H ENAs is influenced by both the surface roughness and the solar zenith angle. We show that the angular distribution of the backscattered ENAs is anisotropic and is influenced by the regolith's structure, which is consistent with Chandrayaan-1 measurements. This work aims for a better understanding of the interactions ongoing at this interface and intends to look into the possibility of deducing information on the surface structure solely from ENA flux measurements. Highlighting the key structural parameters influencing the ENA backscattering will also help the development of models of surface-bounded exospheres.

Keywords: planetary surfaces; regolith
A Highly Settled Disk around Oph163131

High dust density in the midplane of protoplanetary disks is favorable for efficient grain growth and can allow fast formation of planetesimals and planets, before disks dissipate. Vertical settling and dust trapping in pressure maxima are two mechanisms allowing dust to concentrate in geometrically thin and high-density regions. In this work, we aim to study these mechanisms in the highly inclined protoplanetary disk SSTC2D J163131.2-242627 (Oph 163131, i ~ 84°). We present new high-angular-resolution continuum and 12CO ALMA observations of Oph 163131. The gas emission appears significantly more extended in the vertical and radial direction compared to the dust emission, consistent with vertical settling and possibly radial drift. In addition, the new continuum observations reveal two clear rings. The outer ring, located at ~100 au, is well-resolved in the observations, allowing us to put stringent constraints on the vertical extent of millimeter dust particles. We model the disk using radiative transfer and find that the scale height of millimeter-sized grains is 0.5 au or less at 100 au from the central star. This value is about one order of magnitude smaller than the scale height of smaller micron-sized dust grains constrained by previous modeling, which implies that efficient settling of the large grains is occurring in the disk. When adopting a parametric dust settling prescription, we find that the observations are consistent with a turbulent viscosity coefficient of about α ≲ 10-5 at 100 au. Finally, we find that the thin dust scale height measured in Oph 163131 is favorable for planetary growth by pebble accretion: a 10 M E planet may grow within less than 10 Myr, even in orbits exceeding 50 au.

Keywords: protoplanetary disks; planet formation; radiative transfer; dust continuum emission
The First Robust Constraints on the Relationship between Dust-to-gas Ratio and Metallicity in Luminous Star-forming Galaxies at High Redshift

We present rest-optical spectroscopic properties of a sample of four galaxies in the Atacama Large Millimeter/submillimeter Array Hubble Ultra Deep Field (ALMA HUDF). These galaxies span the redshift range $1.41\leqslant z\leqslant 2.54$ and the stellar mass range $10.36\leqslant \mathrm{log}({M}_{* }/{M}_{\odot })\leqslant 10.91$ . They have existing far-infrared and radio measurements of dust-continuum and molecular gas emission from which bolometric star formation rates (SFRs), dust masses, and molecular gas masses have been estimated. We use new H- and K-band near-infrared spectra from the Keck/Multi-object Spectrometer for Infrared Exploration (MOSFIRE) to estimate SFRs from dust-corrected Hα emission (SFR(Hα)) and gas-phase oxygen abundances from the ratio [N II] $\lambda 6584$ /Hα. We find that the dust-corrected SFR(Hα) is systematically lower than the bolometric SFR by a factor of several, and measure gas-phase oxygen abundances in a narrow range, $12+\mathrm{log}({\rm{O/H}})=8.59-8.69$ ( $0.8\mbox{--}1.0\ {({\rm{O/H}})}_{\odot }$ ). Relative to a large z ∼ 2 comparison sample from the MOSFIRE Deep Evolution Field (MOSDEF) survey, the ALMA HUDF galaxies scatter roughly symmetrically around the best-fit linear mass-metallicity relation, providing tentative evidence for a flattening in the SFR dependence of metallicity at high stellar mass. Combining oxygen abundances with estimates of dust and molecular gas masses, we show that there is no significant evolution in the normalization of the dust-to-gas ratio (DGR) versus metallicity relation from z ∼ 0 to z ∼ 2. This result is consistent with some semi-analytic models and cosmological simulations describing the evolution of dust in galaxies. Tracing the actual form of the DGR versus metallicity relation at high redshift now requires combined measurements of dust, gas, and metallicity over a significantly wider range in metallicity. * Based on data 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, and was made possible by the generous financial support of the W.M. Keck Foundation.

Keywords: high-redshift galaxies; galaxy evolution; interstellar medium; gas-to-dust ratio; metallicity
An Information Theoretic Framework for Classifying Exoplanetary System Architectures

We propose several descriptive measures to characterize the arrangements of planetary masses, periods, and mutual inclinations within exoplanetary systems. These measures are based on complexity theory and capture the global, system-level trends of each architecture. Our approach considers all planets in a system simultaneously, facilitating both intrasystem and intersystem analysis. We find that based on these measures, Kepler's high-multiplicity (N ≥ 3) systems can be explained if most systems belong to a single intrinsic population, with a subset of high-multiplicity systems (∼20%) hosting additional, undetected planets intermediate in period between the known planets. We confirm prior findings that planets within a system tend to be roughly the same size and approximately coplanar. We find that forward modeling has not yet reproduced the high degree of spacing similarity (in log-period) actually seen in the Kepler data. Although our classification scheme was developed using compact Kepler multis as a test sample, our methods can be immediately applied to any other population of exoplanetary systems. We apply this classification scheme to (1) quantify the similarity between systems, (2) resolve observational biases from physical trends, and (3) identify which systems to search for additional planets and where to look for these planets.

Keywords: exoplanet systems; astroinformatics; classification systems
Minor Mergers Are Not Enough: The Importance of Major Mergers during Brightest Cluster Galaxy Assembly

We investigate the roles of major and minor mergers during brightest cluster galaxy (BCG) assembly using surface brightness profiles, line indices, and fundamental plane relations. Based on our own sample and consistently reanalyzed Sloan Digital Sky Survey data, we find that BCGs and luminous normal ellipticals (LNEs) have similar central velocity dispersions, central absorption line strengths, and central surface brightnesses. However, BCGs are more luminous due to their much larger radial extent. These properties result in a flattening of the Faber-Jackson and Mgb-luminosity relations above 1010.6 ${L}_{\odot ,g^{\prime} }$ . We use this effect to estimate an amount of 60%-80% of accreted and merged light in BCGs relative to LNEs, which agrees with results from cosmological simulations. We determine the contribution of this excess light (EL) at each radius from the difference between the surface flux profiles of BCGs and LNEs. It is small in the center but increases steeply to 50% at ~3 kpc radius. The shape of these profiles suggests that BCGs could be formed from LNEs in three major merger processes. This is also consistent with the mild increase of the Sérsic indices from n ≈ 4 to n ≈ 6, as confirmed in merger simulations. We note that minor mergers cannot be the dominant origin of the BCG's EL because they deposit too few stars at intermediate radii r ≲ 20 kpc. The shape of the EL profile also explains a detected offset of 0.14 dex of the fundamental planes for BCGs and LNEs relative to each other.

Keywords: galaxy formation; scaling relations; elliptical galaxies; galaxy photometry; galaxy spectroscopy
The Effect of Metallicity on the Nonequilibrium Abundance of Hydrogen-dominated Exoplanet Atmospheres

The atmospheric metallicity greatly influences the composition of exoplanet atmospheres. The effect of metallicity on the thermochemical equilibrium is well studied, though its effect on the disequilibrium abundance is loosely constrained. In this study, we have used the quenching approximation to study the effect of metallicity on the quenched abundance for a range of parameters (temperature: 500-2500 K, pressure: 10-4-103 bar, metallicity: 0.1-1000× solar metallicity). We determine the chemical timescale by finding rate-limiting steps in a reduced chemical network with a network-analysis tool and the thermochemical equilibrium abundance. The equilibrium abundance results are similar to the literature. The CO, H2O, and CO2 abundances increase with metallicity in the parameter range considered. The CH4 abundance increases with metallicity for CO/CH4 < 1 and is unaffected for CO/CH4 > 1. The chemical timescale of CO shows minimal change with metallicity, while the CH4 chemical timescale is inversely proportional to atmospheric metallicity. The quench level of CO shifts into the high-pressure region, and the quench level of CH4 shows complex behavior with metallicity. We benchmarked the quenching approximation with a one-dimensional photochemistry-transport model for two test exoplanets (GJ 1214 b and HD 189733 b) and found it to be in good agreement. We also found that the quenching approximation is a powerful tool to constrain atmospheric parameters. We demonstrated this by constraining the metallicity and transport strength for the test exoplanets HR 8799 b, HD 189733 b, GJ 436 b, and WASP-39 b.

Keywords: exoplanet atmospheres; metallicity; atmospheric composition
No Surviving SN Ia Companion in SNR 0509-67.5: Stellar Population Characterization and Comparison to Models

The community agrees that Type Ia supernovae arise from carbon/oxygen white dwarfs undergoing thermonuclear runaway. However, the full progenitor system and the process that prompts the white dwarf to explode remain unknown. Most current models suggest that the white dwarf explodes because of interaction with a binary companion that may survive the process and remain within the resulting remnant of the exploded star. Furthermore, both the pre-supernova interaction process and the explosion of the primary are expected to imprint a significant departure from ordinary stellar radii and temperatures onto the secondary, making the star identifiable against the unrelated stellar population. Identification of a surviving companion inside an SN Ia remnant might confirm a specific corresponding SN Ia progenitor channel based on the identity of the companion. We conducted a surviving companion search of the Type Ia remnant SNR 0509-67.5 based in the Large Magellanic Cloud. The well-constrained distance to and foreground extinction of the Large Magellanic Cloud allow for Bayesian inference of stellar parameters with low correlation and uncertainties. We present a deep catalog of fully characterized stars interior to SNR 0509-67.5 with radii, effective temperatures, and metallicities inferred using combined Hubble Space Telescope photometric observations across multiple visits. We then compile a list of surviving companion models appropriate for the age of the remnant (roughly 400 yr after the explosion). We compare these predictions with the inferred stellar parameters and conclude that none of the stars are consistent with the predicted signatures of a surviving companion.

Keywords: type ia supernovae; supernova remnants; white dwarf stars; supernovae; ab photometry; large magellanic cloud
Probing the Origin of Cosmic Rays in Cygnus Cocoon Using Ultrahigh-energy Gamma-Ray and Neutrino Observations

Recent ultrahigh-energy gamma-ray observations by the High Altitude Water Cherenkov Observatory up to 100 TeV and LHAASO observatories up to 1.4 PeV energies from the direction of Fermi Large Area Telescope 4FGL source 4FGL J2028.6 + 4110e (Cygnus Cocoon) are indicative of a hadronic origin over a leptonic process for their creation. The IceCube Neutrino Observatory has reported IceCube-201120A, a neutrino event coming from the same direction, suggesting that the Cygnus Cocoon may correspond to one of the most plausible sources of high-energy cosmic rays. The apparent relationship of the neutrino event with the observed ultrahigh-energy gamma rays from the Cygnus Cocoon is investigated in this work to study if it can be explained consistently in hadronic interactions of accelerated cosmic rays with ambient matter. Our findings reveal that leptonic mechanisms, together with pure hadronic mechanisms, make a considerable contribution to the understanding of the total electromagnetic spectrum as well as the observed neutrino event. The estimate of expected muon neutrino events from the Cygnus Cocoon agrees with the one muon neutrino event detected so far in IceCube multiyear observations. Thus, our results are indicative of the potential of the Cygnus Cocoon to be a Galactic cosmic-ray source capable of accelerating at least up to PeV energies.

Keywords: cosmic ray sources; cosmic rays