adsabs/SciX_UAT_keywords huggingface dataset:
Collisional Growth and Fragmentation of Dust Aggregates. II. Mass Distribution of Icy Fragments

By performing N-body simulations, we investigated the fundamental processes of collisions between dust aggregates composed of submicron-sized icy dust monomers. We examined the mass distribution of fragments in the collisional outcomes in a wide range of the mass ratio and the collision velocity between colliding dust aggregates. We derived analytic expressions of the mass distribution of large remnants and small fragments by numerical fitting to the simulation results. Our analytic formulae for masses of the large remnants can reproduce the contribution of mass transfer from a large target to a small projectile, which occurs for a mass ratio of ≳3 and is shown in a previous study. We found that the power-law index of the cumulative mass distribution of the small fragments is independent of the mass ratio and only weakly dependent on the collision velocity. On the other hand, the mass fraction of fragments of individual dust monomers decreases with an increasing total mass of colliding aggregates for a fixed mass ratio. This tendency implies that multiple hierarchical disruptive collisions (i.e., collisions between fragments, and collisions between fragments of fragments) are required for producing a large number of individual dust monomers via collisional fragmentation. Our fragment model suggests that the total geometric cross section integrated over the fragments is estimated to be about the same order as the geometric cross section of the target.

Keywords: interstellar dust; n-body simulations; protoplanetary disks
The Disturbed and Globular-cluster-rich Ultradiffuse Galaxy UGC 9050-Dw1

We investigate the ultradiffuse galaxy (UDG) UGC 9050-Dw1, which was selected because of its disturbed morphology as part of a larger sample of UDGs that display evidence for significant interactions. We use the Hubble Space Telescope's Advanced Camera for Surveys to identify globular clusters (GCs) associated with UGC 9050-Dw1, and the Jansky Very Large Array to measure its H I content. UGC 9050-Dw1, a neighbor to the low surface brightness spiral UGC 9050, exhibits a unique UV-bright central "clump" with clearly associated H I gas and an extended stellar tidal plume to the north. We identify 52 ± 12 GCs, implying a specific frequency of S N = 122 ± 38, one of the highest reported for a UDG of this luminosity ( $\mathrm{log}{L}_{V}/{L}_{\odot }=7.5\pm 0.1$ ). Additionally, ~20% of the total light of the galaxy is contributed by GCs. Nearly uniform GC colors suggest they were formed during a single intense episode of star formation. We posit that UGC 9050-Dw1 represents the initial definitive observational example of UDG formation resulting from a dwarf merger event, where subsequent clumpy star formation has contributed to its present observed characteristics.

Keywords: galaxy interactions; low surface brightness galaxies; dwarf galaxies; tidal tails; globular star clusters; h i line emission; galaxy formation
Flux Ropes, Turbulence, and Collisionless Perpendicular Shock Waves: High Plasma Beta Case

With the onset of solar maximum and the expected increased prevalence of interplanetary shock waves, Parker Solar Probe is likely to observe numerous shocks in the next few years. An outstanding question that has received surprisingly little attention has been how turbulence interacts with collisionless shock waves. Turbulence in the supersonic solar wind is described frequently as a superposition of a majority 2D and a minority slab component. We formulate a collisional perpendicular shock-turbulence transmission problem in a way that enables investigation of the interaction and transmission of quasi-perpendicular fluctuations such as magnetic flux ropes/islands and vortices as well as entropy and acoustic modes in the large plasma beta regime. We focus on the transmission of an upstream spectrum of these modes, finding that the downstream spectral amplitude is typically increased significantly (a factor of 10 or more), and that the upstream spectral index of the inertial range, and indeed the general spectral shape, is unchanged for the downstream magnetic variance, kinetic energy, and density variance. A comparison of the theoretically predicted downstream magnetic variance, kinetic energy, and density variance spectra with those observed at 1, 5, and 84 au by Wind, Ulysses, and Voyager 2 shows excellent agreement. The overall theoretically predicted characteristics of the transmission of turbulence across shocks observed in the solar wind appear to be largely consistent with recent observational studies by Pitňa et al. and Borovsky.

Keywords: interplanetary shocks; interplanetary turbulence
Rest-frame Near-infrared Radial Light Profiles up to z = 3 from JWST/NIRCam: Wavelength Dependence of the Sérsic Index

We examine the wavelength dependence of radial light profiles based on Sérsic index n measurements of 1067 galaxies with M * ≥ 109.5 M ⊙ and in the redshift range 0.5 < z < 3. The sample and rest-frame optical light profiles are drawn from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) and 3D Hubble Space Telescope (HST); rest-frame near-infrared light profiles are inferred from images collected for the Cosmic Evolution Early Release Science (CEERS) program with the Near Infrared Camera (NIRCam) on board of the James Webb Space Telescope (JWST). n shows only a weak dependence on the wavelength, regardless of the redshift, galaxy mass, and type. On average, star-forming galaxies have n = 1-1.5 and quiescent galaxies have n = 3-4 in the rest-frame optical and near-infrared. The strong correlation at all wavelengths between n and star formation activity implies a physical connection between the radial stellar mass profile and star formation activity. The main caveat is that the current sample is too small to discern trends for the most massive galaxies (M * > 1011 M ⊙).

Keywords: galaxy structure; galaxy evolution; galaxy luminosities; galaxy quenching
A Census of Star Formation Histories of Massive Galaxies at 0.6 < z < 1 from Spectrophotometric Modeling Using Bagpipes and Prospector

We present individual star formation histories (SFHs) of ~3000 massive galaxies (log(M */M ⊙) > 10.5) from the Large Early Galaxy Astrophysics Census spectroscopic survey at a lookback time of ~7 billion yr and quantify the population trends leveraging 20 hr deep-integrated spectra of these ~1800 star-forming and ~1200 quiescent galaxies at 0.6 < z < 1.0. Essentially all galaxies at this epoch contain stars of age <3 Gyr, in contrast with older massive galaxies today, facilitating better recovery of previous generations of star formation at cosmic noon and earlier. We conduct spectrophotometric analysis using parametric and nonparametric Bayesian stellar population synthesis modeling tools-Bagpipes and Prospector-to constrain the median SFHs of this mass complete sample and characterize population trends. A consistent picture arises for the late-time stellar mass growth when quantified as t 50 and t 90, corresponding to the age of the Universe when galaxies formed 50% and 90% of their total stellar mass, although the two methods disagree at the earliest formation times (e.g., t 10). Our results reveal trends in both stellar mass and stellar velocity dispersion as in the local Universe-low-mass galaxies with shallower potential wells grow their stellar masses later in cosmic history compared to high-mass galaxies. Unlike local quiescent galaxies, the median duration of late-time star formation (τ SF,late = t 90-t 50) does not consistently depend on the stellar mass. This census sets a benchmark for future deep spectrophotometric studies of the more distant Universe.

Keywords: galaxy evolution; galaxy formation; galaxy stellar content; galaxy spectroscopy; galaxy photometry; bayesian statistics; star formation
A Search for Kilonova Radio Flares in a Sample of Swift/BAT Short Gamma-Ray Bursts

The multimessenger detection of GW170817 showed that binary neutron star (BNS) mergers are progenitors of (at least some) short gamma-ray bursts (GRBs), and that short GRB jets (and their afterglows) can have structures (and observational properties) more complex than predicted by the standard top-hat jet scenario. Indeed, the emission from the structured jet launched in GW170817 peaked in the radio band (centimeter wavelengths) at ≈100 days since merger-a timescale much longer than the typical time span of radio follow-up observations of short GRBs. Moreover, radio searches for a potential late-time radio flare from the fast tail of the neutron-rich debris that powered the kilonova associated with GW170817 (AT 2017gfo) have extended to even longer timescales (years after the merger). In light of this, here we present the results of an observational campaign targeting a sample of seven, years-old GRBs in the Swift/BAT sample with no redshift measurements and no promptly identified X-ray counterpart. Our goal is to assess whether this sample of short GRBs could harbor nearby BNS mergers, searching for the late-time radio emission expected from their ejecta. We found one radio candidate counterpart for one of the GRBs in our sample, GRB 111126A, though an origin related to emission from star formation or from an active galactic nucleus in its host galaxy cannot be excluded without further observations.

Keywords: gravitational waves; gamma-ray bursts; non-thermal radiation sources; radio continuum emission
A Long-lived Lunar Magnetic Field Powered by Convection in the Core and a Basal Magma Ocean

An internally generated magnetic field once existed on the Moon. This field reached high intensities (~10-100 μT, perhaps intermittently) from ~4.3 to 3.6 Gyr ago and then weakened to ≲5 μT before dissipating by ~1.9-0.8 Gyr ago. While the Moon's metallic core could have generated a magnetic field via a dynamo powered by vigorous convection, models of a core dynamo often fail to explain the observed characteristics of the lunar magnetic field. In particular, the core alone may not contain sufficient thermal, chemical, or radiogenic energy to sustain the high-intensity fields for >100 Myr. A recent study by Scheinberg et al. suggested that a dynamo hosted in electrically conductive, molten silicates in a basal magma ocean (BMO) may have produced a strong early field. However, that study did not fully explore the BMO's coupled evolution with the core. Here we show that a coupled BMO-core dynamo driven primarily by inner core growth can explain the timing and staged decline of the lunar magnetic field. We compute the thermochemical evolution of the lunar core with a 1D parameterized model tied to extant simulations of mantle evolution and BMO solidification. Our models are most sensitive to four parameters: the abundances of sulfur and potassium in the core, the core's thermal conductivity, and the present-day heat flow across the core-mantle boundary. Our models best match the Moon's magnetic history if the bulk core contains ~6.5-8.5 wt% sulfur, in agreement with seismic structure models.

Keywords: lunar magnetic fields; lunar interior
The PAndAS View of the Andromeda Satellite System. III. Dwarf Galaxy Detection Limits

We determine the detection limits of the search for dwarf galaxies in the Pan-Andromeda Archaeological Survey (PAndAS) using the algorithm developed by the PAndAS team. The recovery fractions of artificial dwarf galaxies are, as expected, a strong function of physical size and luminosity and, to a lesser extent, distance. We show that these recovery fractions vary strongly with location in the surveyed area because of varying levels of contamination from both the Milky Way foreground stars and the stellar halo of Andromeda. We therefore provide recovery fractions that are a function of size, luminosity, and location within the survey on a scale of ~1 × 1 deg2 (or ~14 × 14 kpc2). Overall, the effective surface brightness for a 50% detection rate ranges between 28 and 30 mag arcsec-2. This is in line with expectations for a search that relies on photometric data that are as deep as the PAndAS survey. The derived detection limits are an essential ingredient on the path to constraining the global properties of Andromeda's system of satellite dwarf galaxies and, more broadly, to providing constraints on dwarf galaxy formation and evolution in a cosmological context.

Keywords: local group; dwarf galaxies; andromeda galaxy
Lyman Continuum Emission Escaping from Luminous Green Pea Galaxies at z = 0.5

Compact starburst galaxies are thought to include many or most of the galaxies from which substantial Lyman continuum emission can escape into the intergalactic medium. Li & Malkan used Sloan Digital Sky Survey photometry to find a population of such starburst galaxies at z ∼ 0.5. They were discovered by their extremely strong [O III] λλ4959+5007 emission lines, which produce a clearly detectable excess brightness in the i bandpass, compared with surrounding filters. We therefore used the Hubble Space Telescope (HST)/COS spectrograph to observe two of the newly discovered i-band excess galaxies around their Lyman limits. One has strongly detected continuum below its Lyman limit, corresponding to a relative escape fraction of ionizing photons of 20% ± 2%. The other, which is less compact in UV imaging, has a 2&sgr; upper limit to its Lyman escape fraction of <5%. Before the UV spectroscopy, the existing data could not distinguish these two galaxies. Although a sample of two is hardly sufficient for statistical analysis, it shows the possibility that some fraction of these strong [O III] emitters as a class have ionizing photons escaping. The differences might be determined by the luck of our particular viewing geometry. Obtaining the HST spectroscopy revealed that the Lyman-continuum-emitting galaxy differs in having no central absorption in its prominent Lyα emission-line profile. The other target, with no escaping Lyman continuum, shows the more common double-peaked Lyα emission.

Keywords: compact dwarf galaxies; reionization; near ultraviolet astronomy; ultraviolet astronomy; emission line galaxies; star formation; starburst galaxies; o stars; h ii regions; primordial galaxies; galaxy evolution
The AMUSING++ Nearby Galaxy Compilation. I. Full Sample Characterization and Galactic-scale Outflow Selection

We present here AMUSING++: the largest compilation of nearby galaxies observed with the MUSE integral-field spectrograph so far. This collection consists of 635 galaxies from different MUSE projects covering the redshift interval 0.0002 < z < 0.1. The sample and its main properties are characterized and described here. It includes galaxies of almost all morphological types, with a good coverage in its color-magnitude diagram, within the stellar mass range between 108 and 1012 M⊙, and with properties resembling those of a diameter-selected sample. The AMUSING++ sample is, therefore, suitable for studying, with unprecendented detail, the properties of nearby galaxies at global and local scales, providing us with more than 50 million individual spectra. We use this compilation to investigate the presence of galactic outflows. We exploit the use of combined emission-line images to explore the shape of the different ionized components and the distribution along classical diagnostic diagrams to disentangle the different ionizing sources across the optical extension of each galaxy. We use the cross-correlation function to estimate the level of symmetry of the emission lines as an indication of the presence of shocks and/or active galactic nuclei. We uncovered a total of 54 outflows, comprising ∼8% of the sample. A large number of the discovered outflows correspond to those driven by active galactic nuclei (∼60%), suggesting some bias in the selection of our sample. No clear evidence was found that outflow host galaxies are highly star-forming, and outflows appear to be found within all galaxies around the star-formation sequence.

Keywords: catalogs; interstellar medium; galactic winds
Exploring the Hubble Tension and Spatial Curvature from the Ages of Old Astrophysical Objects

We use the age measurements of 114 old astrophysical objects (OAO) in the redshift range 0 ≲ z ≲ 8 to explore the Hubble tension. The age of the universe at any z is inversely proportional to the Hubble constant, H 0, so requiring the universe to be older than the OAO it contains at any z will lead to an upper limit on H 0. Assuming flat ΛCDM and setting a Gaussian prior on the matter density parameter Ωm = 0.315 ± 0.007 informed by Planck, we obtain a 95% confidence level upper limit of H 0 < 70.6 km s-1 Mpc-1, representing a 2σ tension with the measurement using the local distance ladder. We find, however, that the inferred upper limit on H 0 depends quite sensitively on the prior for Ωm, and the Hubble tension between early-time and local measurements of H 0 may be due in part to the inference of both Ωm and H 0 in Planck, while the local measurement uses only H 0. The age-redshift data may also be used for cosmological model comparisons. We find that the R h = ct universe accounts well for the data, with a reasonable upper limit on H 0, while Einstein-de Sitter fails to pass the cosmic-age test. Finally, we present a model-independent estimate of the spatial curvature using the ages of 61 galaxies and the luminosity distances of 1048 Pantheon Type Ia supernovae. This analysis suggests that the geometry of the universe is marginally consistent with spatial flatness at a confidence level of 1.6σ, characterized as ${{\rm{\Omega }}}_{k}={0.43}_{-0.27}^{+0.27}$ .

Keywords: cosmological models; cosmological parameters; hubble constant; galaxy ages; type ia supernovae
Equation-of-state Table with Hyperon and Antikaon for Supernova and Neutron Star Merger

We develop a new equation-of-state (EOS) table involving thermal (anti)kaons, Bose-Einstein condensate of K- mesons, and Λ-hyperons for core-collapse supernova and neutron star merger simulations. This EOS table is based on a finite-temperature, density-dependent relativistic hadron field theory where baryon-baryon interaction is mediated by scalar σ, vector ω, and ρ mesons, using the parameter set DD2 for nucleons. The repulsive hyperon-hyperon interaction is mediated by an additional strange φ meson. The EOS for the K- condensed matter is also calculated within the framework of the relativistic mean field model, whereas the low-density, inhomogeneous matter is calculated in the extended nuclear statistical equilibrium model. The EOS table is generated for a wide range of values of three parameters—baryon density (10-12 to ∼1 fm-3), positive charge fraction (0.01-0.60), and temperature (0.1-158.48 MeV).

Keywords: neutron stars; nuclear astrophysics; stellar mergers; core-collapse supernovae
Long-term Evolution of a Supernova Remnant Hosting a Double Neutron Star Binary

An ultra-stripped supernova (USSN) is a type of core-collapse supernova explosion proposed to be a candidate formation site of a double neutron star (DNS) binary. We investigate the dynamical evolution of an ultra-stripped supernova remnant (USSNR), which should host a DNS at its center. By accounting for the mass-loss history of the progenitor binary using a model developed by a previous study, we construct the large-scale structure of the circumstellar medium (CSM) up to a radius ~100 pc, and simulate the explosion and subsequent evolution of a USSN surrounded by such a CSM environment. We find that the CSM encompasses an extended region characterized by a hot plasma with a temperature ~108 K located around the termination shock of the wind from the progenitor binary (~10 pc), and the USSNR blast wave is drastically weakened while penetrating through this hot plasma. Radio continuum emission from a young USSNR is sufficiently bright to be detectable if it inhabits our galaxy but faint compared to the observed Galactic supernova remnants (SNRs), and thereafter declines in luminosity through adiabatic cooling. Within our parameter space, USSNRs typically exhibit a low radio luminosity and surface brightness compared to the known Galactic SNRs. Due to the small event rate of USSNe and their relatively short observable life span, we calculate that USSNRs account for only ~0.1%-1% of the total SNR population. This is consistent with the fact that no SNR hosting a DNS binary has been discovered in the Milky Way so far.

Keywords: supernova remnants
Kepler Multitransiting System Physical Properties and Impact Parameter Variations

We fit a dynamical model to Kepler systems that contain four or more transiting planets using the analytic method AnalyticLC and obtain physical and orbital parameters for 101 planets in 23 systems, of which 95 are of mass significance better than 3σ, and 46 are without previously reported mass constraints or upper limits. In addition, we compile a list of 71 Kepler objects of interest that display significant transit impact parameter variations (TbVs), complementing our previously published work on two- and three-transiting-planet systems. Together, these works include the detection of significant TbV signals of 130 planets, which is, to our knowledge, the largest catalog of this type to date. The results indicate that the typical detectable TbV rate in the Kepler population is of order 10‑2 yr‑1 and that rapid TbV rates (≳0.05 yr‑1) are observed only in systems that contain a transiting planet with an orbital period less than ∼20 days. The observed TbV rates are only weakly correlated with orbital period within Kepler's ≲100-day-period planets. If this extends to longer periods, it implies a limit on the utility of the transit technique for long-period planets. The TbVs we find may not be detectable in direct impact parameter measurements, but rather are inferred from the full dynamics of the system, encoded in all types of transit variations. Finally, we find evidence that the mutual inclination distribution is qualitatively consistent with the previously suggested angular momentum deficit model using an independent approach.

Keywords: exoplanets; exoplanet dynamics; celestial mechanics
Velocity Dispersions of Massive Quiescent Galaxies from Weak Lensing and Spectroscopy

We use MMT spectroscopy and deep Subaru Hyper Suprime-Cam (HSC) imaging to compare the spectroscopic central stellar velocity dispersion of quiescent galaxies with the effective dispersion of the dark matter halo derived from the stacked lensing signal. The spectroscopic survey (the Smithsonian Hectospec Lensing Survey) provides a sample of 4585 quiescent galaxy lenses with measured line-of-sight central stellar velocity dispersion (σSHELS) that is more than 85% complete for R < 20.6, Dn4000 > 1.5 and M⋆ > 109.5M⊙. The median redshift of the sample of lenses is 0.32. We measure the stacked lensing signal from the HSC deep imaging. The central stellar velocity dispersion is directly proportional to the velocity dispersion derived from the lensing σLens, ${\sigma }_{\mathrm{Lens}}\,=(1.05\pm 0.15){\sigma }_{\mathrm{SHELS}}+(-21.17\pm 35.19)$ . The independent spectroscopic and weak lensing velocity dispersions probe different scales, ∼3 kpc and ≳100 kpc, respectively, and strongly indicate that the observable central stellar velocity dispersion for quiescent galaxies is a good proxy for the velocity dispersion of the dark matter halo. We thus demonstrate the power of combining high-quality imaging and spectroscopy to shed light on the connection between galaxies and their dark matter halos. * Based on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

Keywords: early-type galaxies; galaxy dark matter halos; weak gravitational lensing; spectroscopy