Sazuna/UAT_keywords huggingface dataset:
Analytic Approach to the Late Stages of Giant Planet Formation. This paper constructs an analytic description for the late stages of giant planet formation. During this phase of evolution, the planet gains the majority of its final mass through gas accretion at a rapid rate. This work determines the density and velocity fields for material falling onto the central planet and its circumplanetary disk, and finds the corresponding column density of this infalling envelope. We derive a steady-state solution for the surface density of the disk as a function of its viscosity (including the limiting case where no disk accretion occurs). Planetary magnetic fields truncate the inner edge of the disk and determine the boundary conditions for mass accretion onto the planet from both direct infall and from the disk. The properties of the forming planet and its circumplanetary disk are determined, including the luminosity contributions from infall onto the planet and disk surfaces, and from disk viscosity. The radiative signature of the planet formation process is explored using a quasi-spherical treatment of the emergent spectral energy distributions. The analytic solutions developed herein show how the protoplanet properties (envelope density distribution, velocity field, column density, disk surface density, luminosity, and radiative signatures) vary with input parameters (instantaneous mass, orbital location, accretion rate, and planetary magnetic field strength).

Keywords: Planetary system formation, Solar system formation, Protoplanetary disks, Planet formation
Simultaneous Dependence of Matter Clustering on Scale and Environment. In this work, we propose new statistical tools that are capable of characterizing the simultaneous dependence of dark matter and gas clustering on the scale and the density environment, and these are the environment-dependent wavelet power spectrum (env-WPS), the environment-dependent bias function (env-bias), and the environment-dependent wavelet cross-correlation function (env-WCC). These statistics are applied to the dark matter and baryonic gas density fields of the TNG100-1 simulation at redshifts of z=3.0-0.0, and to Illustris-1 and SIMBA at z = 0. The measurements of the env-WPSs suggest that the clustering strengths of both the dark matter and the gas increase with increasing density, while that of a Gaussian field shows no density dependence. By measuring the env-bias and env-WCC, we find that they vary significantly with the environment, scale, and redshift. A noteworthy feature is that at z = 0.0, the gas is less biased in denser environments of Δ ≳ 10 around 3 h Mpc-1, due to the gas reaccretion caused by the decreased AGN feedback strength at lower redshifts. We also find that the gas correlates more tightly with the dark matter in both the most dense and underdense environments than in other environments at all epochs. Even at z = 0, the env-WCC is greater than 0.9 in Δ ≳ 200 and Δ ≲ 0.1 at scales of k ≲ 10 h Mpc-1. In summary, our results support the local density environment having a non-negligible impact on the deviations between dark matter and gas distributions up to large scales.

Keywords: Intergalactic medium, Dark matter, Wavelet analysis, Large-scale structure of the universe
Implications of an Extended Dark Energy Model with Massive Neutrinos. Recently there have been reports of finding a lower bound on the neutrino mass parameter (Σm  ν ) when using the Atacama Cosmology Telescope (ACT) and SPTpol data; however, these bounds on the Σm  ν  are still weaker for most cases around the 1σ level. In this context, here in this work, we study the consequences of using an enlarged four parameter dynamical dark energy equation of state on the neutrino mass parameter as well as on the Hubble and S8 tensions. The four parameter dark energy equation of state incorporates a generic nonlinear monotonic evolution of the dark energy equation of state, where the four parameters are the early and the present value of the equation of state, the transition scale factor, and the sharpness of the transition. We report that with lensing-marginalized Planck + BAO + Pantheon and prior on absolute magnitude M  B , and KIDS/Viking S 8 prior, the model favors a nonzero value for the neutrino mass parameter at most at the 1σ level ( ${\rm{\Sigma }}{m}_{\nu }={0.1847}_{-0.165}^{+0.0698}$ eV). In this case this model also brings down the Hubble tension to a 2.5σ level and the S8 tension to a ~1.5σ level. This model also provides tighter constraints on the value of the dark energy equation of state at present epoch w 0 ( ${w}_{0}=-{0.9901}_{-0.0766}^{+0.0561}$ ) in comparison to the Chevalier-Polarski and Linder-like parameterization.

Keywords: Dark energy
On the H I Content of MaNGA Major Merger Pairs. The role of H I content in galaxy interactions is still under debate. To study the H I content of galaxy pairs at different merging stages, we compile a sample of 66 major-merger galaxy pairs and 433 control galaxies from the Sloan Digital Sky Survey IV (SDSS-IV) MaNGA IFU survey. In this study, we adopt kinematic asymmetry as a new effective indicator to describe the merging stage of galaxy pairs. With archival data from the HI-MaNGA survey and new observations from the Five-hundred-meter Aperture Spherical radio Telescope (FAST), we investigate the differences in H I gas fraction (f H I), star formation rate (SFR), and H I star formation efficiency (SFEH I) between the pair and control samples. Our results suggest that the H I gas fraction of major-merger pairs on average is marginally decreased by ~15% relative to isolated galaxies, implying mild H I depletion during galaxy interactions. Compared to isolated galaxies, pre-passage paired galaxies have similar f H I, SFR, and SFEH I, while pairs during the pericentric passage have weakly decreased f H I (-0.10 ± 0.05 dex), significantly enhanced SFR (0.42 ± 0.11 dex), and SFEH I (0.48 ± 0.12 dex). When approaching the apocenter, paired galaxies show marginally decreased f H I (-0.05 ± 0.04 dex), comparable SFR (0.04 ± 0.06 dex), and SFEH I (0.08 ± 0.08 dex). We propose that the marginally detected H I depletion may originate from the gas consumption in fueling the enhanced H2 reservoir of galaxy pairs. In addition, new FAST observations also reveal a H I absorber (N H I ~ 4.7 × 1021 cm-2), which may suggest gas infalling and the triggering of active galactic nuclei activity.

Keywords: Interstellar atomic gas, Galaxy interactions, Galaxy pairs, Star formation, Galaxy mergers
The Origin of the [C II] Deficit in a Simulated Dwarf Galaxy Merger-driven Starburst. We present [C II] synthetic observations of smoothed particle hydrodynamics (SPH) simulations of a dwarf galaxy merger. The merging process varies the star formation rate (SFR) by more than three orders of magnitude. Several star clusters are formed, the feedback of which disperses and unbinds the dense gas through expanding H II regions and supernova (SN) explosions. For galaxies with properties similar to the modeled ones, we find that the [C II] emission remains optically thin throughout the merging process. We identify the warm neutral medium ( $3\lt \mathrm{log}{T}_{\mathrm{gas}}\lt 4$ with χ HI &gt; 2χ H2) to be the primary source of [C II] emission (~58% contribution), although at stages when the H II regions are young and dense (during star cluster formation or SNe in the form of ionized bubbles), they can contribute ≳50% to the total [C II] emission. We find that the [C II]/far-IR (FIR) ratio decreases owing to thermal saturation of the [C II] emission caused by strong far-UV radiation fields emitted by the massive star clusters, leading to a [C II] deficit medium. We investigate the [C II]-SFR relation and find an approximately linear correlation that agrees well with observations, particularly those from the Dwarf Galaxy Survey. Our simulation reproduces the observed trends of [C II]/FIR versus ΣSFR and ΣFIR, and it agrees well with the Kennicutt relation of SFR-FIR luminosity. We propose that local peaks of [C II] in resolved observations may provide evidence for ongoing massive cluster formation.

Keywords: Photodissociation regions, Radiative transfer simulations, Interstellar medium
Different Ice-shell Geometries on Europa and Enceladus due to Their Different Sizes: Impacts of Ocean Heat Transport. On icy worlds, the ice shell and subsurface ocean form a coupled system-heat and salinity flux from the ice shell induced by the ice-thickness gradient drives circulation in the ocean, and in turn, the heat transport by ocean circulation shapes the ice shell. Therefore, understanding the dependence of the efficiency of ocean heat transport (OHT) on orbital parameters may allow us to predict the ice-shell geometry before direct observation is possible, providing useful information for mission design. Inspired by previous works on baroclinic eddies, I first derive scaling laws for the OHT on icy moons, driven by ice topography, and then verify them against high-resolution 3D numerical simulations. Using the scaling laws, I am then able to make predictions for the equilibrium ice-thickness variation knowing that the ice shell should be close to heat balance. The ice shell on small icy moons (e.g., Enceladus) may develop strong thickness variations between the equator and pole driven by the polar-amplified tidal dissipation in the ice; in contrast, the ice shell on large icy moons (e.g., Europa, Ganymede, Callisto, etc.) tends to be flat due to the smoothing effects of the efficient OHT. These predictions are manifested by the different ice-evolution pathways simulated for Enceladus and Europa, considering the ice freezing/melting induced by ice dissipation, conductive heat loss, and OHT as well as the mass redistribution by ice flow.

Keywords: Galilean satellites, Saturnian satellites, Europa
Opacity of the Highly Ionized Lanthanides and the Effect on the Early Kilonova. We investigate the effect of the presence of lanthanides (Z = 57-71) on the kilonova at t ~ 1 hr after the neutron star merger for the first time. For this purpose, we calculate the atomic structures and the opacities for selected lanthanides: Nd (Z = 60), Sm (Z = 62), and Eu (Z = 63). We consider the ionization degree up to 10th (XI), applicable for the ejecta at t ~ a few hours after the merger, when the temperature is T ~ 105 K. We find that the opacities for the highly ionized lanthanides are exceptionally high, reaching ${\kappa }_{\exp }\sim 1000\,{\mathrm{cm}}^{2}\,{{\rm{g}}}^{-1}$ for Eu, due to the highly dense energy levels. Using the new opacity, we perform radiative transfer simulations to show that the early light curves become fainter by a (maximum) factor of four, in comparison to lanthanide-free ejecta at t ~ 0.1 days. However, the period at which the light curves are affected is relatively brief owing to the rapid time evolution of the opacity in the outermost layer of the ejecta. We predict that for a source at a distance of ~100 Mpc, UV brightness for lanthanide-rich ejecta shows a drop to ~21-22 mag at t ~ 0.1 days and the UV peaks around t ~ 0.2 days with a magnitude of ~19 mag. Future detection of such a kilonova by an existing UV satellite like Swift or the upcoming UV satellite ULTRASAT will provide useful constraints on the abundance in the outer ejecta and the corresponding nucleosynthesis conditions in the neutron star mergers.

Keywords: Neutron stars, Nucleosynthesis, R-process, Stellar atmospheric opacity, Radiative transfer, Gravitational waves
Exploring the Hadronic Origin of LHAASO J1908+0621. Recent observations by the Large High Altitude Air Shower Observatory (LHAASO) have paved the way for the observational detection of PeVatrons in the Milky Way, thus revolutionizing the field of γ-ray astrophysics. In this paper, we study one such detected source, LHAASO J1908+0621, and explore the origin of multi-TeV γ-ray emission from this source. A middle-aged radio supernova remnant SNR G40.5-0.5 and a GeV pulsar PSR J1907+0602 are cospatial with LHAASO J1908+0621. Dense molecular clouds are also found to be associated with SNR G40.5-0.5. We explain the multi-TeV γ-ray emission observed from the direction of LHAASO J1908+0621, by the hadronic interaction between accelerated protons that escaped from the SNR shock front and cold protons present inside the dense molecular clouds, and the leptonic emission from the pulsar wind nebula (PWN) associated with the pulsar J1907+0602. Moreover, we explain lower energy γ-ray emission by considering the radiative cooling of the electrons that escaped from SNR G40.5-0.5. Finally, the combined lepto-hadronic scenario was used to explain the multiwavelength spectral energy distribution of LHAASO J1908+0621. Although not yet significant, an IceCube hotspot of neutrino emission is spatially associated with LHAASO J1908+0621, indicating a possible hadronic contribution. In this paper, we show that if a hadronic component is present in LHAASO J1908+0621, then the second-generation IceCube observatory will detect neutrinos from this source.

Keywords: High energy astrophysics, Gamma-ray sources, Molecular clouds, Supernova remnants, Gamma-rays
The WISE-2MASS Survey: Red Quasars Into the Radio Quiet Regime. We present a highly complete sample of broad-line (Type 1) QSOs out to z ~ 3 selected by their mid-infrared colors, a method that is minimally affected by dust reddening. We remove host-galaxy emission from the spectra and fit for excess reddening in the residual QSOs, resulting in a Gaussian distribution of colors for unreddened (blue) QSOs, with a tail extending toward heavily reddened (red) QSOs, defined as having E(B - V) &gt; 0.25. This radio-independent selection method enables us to compare red and blue QSO radio properties in both the FIRST (1.4 GHz) and VLASS (2-4 GHz) surveys. Consistent with recent results from optically selected QSOs from SDSS, we find that red QSOs have a significantly higher detection fraction and a higher fraction of compact radio morphologies at both frequencies. We employ radio stacking to investigate the median radio properties of the QSOs including those that are undetected in FIRST and VLASS, finding that red QSOs have significantly brighter radio emission and steeper radio spectral slopes compared with blue QSOs. Finally, we find that the incidence of red QSOs is strongly luminosity dependent, where red QSOs make up &gt;40% of all QSOs at the highest luminosities. Overall, red QSOs comprise ~40% of higher luminosity QSOs, dropping to only a few percent at lower luminosities. Furthermore, red QSOs make up a larger percentage of the radio-detected QSO population. We argue that dusty AGN-driven winds are responsible for both the obscuration as well as excess radio emission seen in red QSOs.

Keywords: Quasars, Surveys, Active galaxies, Radio quiet quasars, Radio loud quasars
Molecular Chemistry for Dark Matter. Molecular cooling is essential for studying the formation of substructure of dissipative dark-matter halos that may host compact objects such as black holes. Here, we analyze the reaction rates relevant for the formation, dissociation, and transition of hydrogenic molecules while allowing for different values of the physical parameters: the coupling constant, the proton mass, and the electron mass. For all cases, we rescale the reaction rates for the standard molecular hydrogen, so our results are valid as long as the dark matter is weakly coupled and one of the fermions is much heavier than the other. These results will allow a robust numerical treatment of cosmic structure, in particular for minihalos for which molecular cooling is important, in a dissipative dark-matter scenario.

Keywords: Cosmology, Molecular physics, Dark matter
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, Molecular physics, Dark matter, Recombination (cosmology)
Molecular Chemistry for Dark Matter. III. DarkKROME. Dark matter that is dissipative may cool sufficiently to form compact objects, including black holes. Determining the abundance and mass spectrum of those objects requires an accurate model of the chemistry relevant for the cooling of the dark matter gas. Here we introduce a chemistry tool for dark matter, DarkKROME, an extension of the KROME software package. DarkKROME is designed to include all atomic and molecular processes relevant for dark matter with two unequal-mass fundamental fermions, interacting via a massless-photon-mediated U(1) force. We use DarkKROME to perform one-zone collapse simulations and study the evolution of temperature-density phase diagrams for various dark sector parameters. DarkKROME is publicly available at https://bitbucket.org/mtryan83/darkkrome.

Keywords: Cosmology, Molecular physics, Dark matter, Collapsing clouds
Swift J0503.7-2819: a Short-period Asynchronous Polar or Stream-fed Intermediate Polar. We analyze a 7.4 hr XMM-Newton light curve of the cataclysmic variable Swift J0503.7-2819, previously classified using optical periods as an intermediate polar (IP) with an orbital period of 0.0567 days. A photometric signal at 975 s, previously suggested to be the spin period, is not present in X-rays and is readily understood as a quasiperiodic oscillation. The X-ray light curve instead shows clear behavior of a highly asynchronous polar or stream-fed IP. It can be described by either of two scenarios: one that switches between one-pole and two-pole accretion, and another in which accretion alternates fully between two poles. The spin periods in these two models are 0.0455 days and 0.0505 days, respectively. The spin frequency ω is thus either 24% faster or 12% faster than the orbital frequency Ω, and the corresponding beat period between spin and orbit is 0.231 days or 0.462 days. Brief absorption events seen in the light curve are spaced in a way that may favor the longer spin and beat periods. These periods are confirmed and refined using data from the Transiting Exoplanet Survey Satellite and the Asteroid Terrestrial-impact Last Alert System. The short beat cycle of Swift J0503.7-2819 makes it well-suited to resolving this common dilemma, which amounts to deciding whether the main signal in the power spectrum is ω or 2ω - Ω.

Keywords: DQ Herculis stars, Cataclysmic variable stars, AM Herculis stars
Ionization Distributions in Outflows of Active Galaxies: Universal Trends and Prospect of Future XRISM Observations. The physics behind the ionization structure of outflows from black holes is yet to be fully understood. Using archival observations with the Chandra/HETG gratings over the past two decades, we measured an absorption measure distribution for a sample of outflows in nine active galactic nuclei (AGNs), namely the dependence of outflow column density, N H, on the ionization parameter, ξ. The slope of $\mathrm{log}$ N H versus $\mathrm{log}\xi $ is found to be between 0.00 and 0.72. We find an anticorrelation between the log of total column density of the outflow and the log of AGN luminosity, and none with the black hole mass and accretion efficiency. A major improvement in the diagnostics of AGN outflows will potentially occur with the launch of the XRISM/Resolve spectrometer. We study the ability of Resolve to reveal the outflow ionization structure by constructing the absorption measure distribution from simulated Resolve spectra, utilizing its superior resolution and effective area. Resolve constrains the column density as well as HETG, but with much shorter observations.

Keywords: Seyfert galaxies, X-ray active galactic nuclei
Constraining the Ellipticity of the Newborn Magnetar with the Observational Data of Long Gamma-Ray Bursts. The X-ray plateau emission observed in many long gamma-ray bursts (LGRBs) has been usually interpreted as the spin-down luminosity of a rapidly spinning, highly magnetized neutron star (millisecond magnetar). If this is true, then the magnetar may emit extended gravitational wave (GW) emission associated with the X-ray plateau due to nonaxisymmetric deformation or various stellar oscillations. The advanced LIGO and Virgo detectors have searched for long-duration GW transients for several years; no evidence of GWs from any magnetar has been found until now. In this work, we attempt to search for signatures of GW radiation in the electromagnetic observation of 30 LGRBs under the assumption of the magnetar model. We utilize the observations of the LGRB plateau to constrain the properties of the newborn magnetar, including the initial spin period P 0, dipole magnetic field strength B  p , and the ellipticity ϵ. We find that there are some tight relations between magnetar parameters, e.g., $\epsilon \propto {B}_{p}^{1.29}$ and ${B}_{p}\propto {P}_{0}^{1.14}$ . In addition, we derive the GW strain for the magnetar sample via their spin-down processes, and find that the GWs from these objects may not be detectable by the aLIGO and Einstein Telescope (ET) detectors. For a rapidly spinning magnetar (P ~ 1 ms, B ~ 1015 G), the detection horizon for the advanced LIGO O5 detector is ~180 Mpc. The detection of such a GW signal associated with the X-ray plateau would be a smoking gun that the central engine of a GRB is a magnetar.

Keywords: Neutron stars, Gamma-ray bursts, Gravitational waves
Debye-scale Solitary Structures in the Martian Magnetosheath. We present an analysis of 450 solitary wave pulses observed by the Langmuir Probe and Waves instrument on the Mars Atmosphere and Volatile EvolutioN spacecraft during its five passes around Mars on 2015 February 9. The magnitude and duration of these pulses vary between 1 and 25 mV m-1 and 0.2-1.7 ms, respectively. The ambient plasma conditions suggest that these pulses are quasi-parallel to the ambient magnetic field and can be considered electrostatic. These pulses are dominantly seen in the dawn (5-6 LT) and afternoon-dusk (15-18 LT) sectors at an altitude of 1000-3500 km. The frequencies of these electric field pulses are close to the ion plasma frequency (i.e., f pi ≤ f ef ≪ f pe), which suggests that their formation is governed by ion dynamics. The computer simulation performed for the Martian magnetosheath plasma hints that these pulses are ion-acoustic solitary waves generated by drifted ion and electron populations and their spatial scales are in the range of few ion Debye lengths (1.65-10λ di). This is the first study to report and model solitary wave structures in the Martian magnetosheath.

Keywords: Space plasmas, Mars, Planetary magnetospheres