adsabs/SciX_UAT_keywords huggingface dataset:
The Bias from Hydrodynamic Simulations: Mapping Baryon Physics onto Dark Matter Fields

This paper investigates the hierarchy of baryon physics assembly bias relations obtained from state-of-the-art hydrodynamic simulations with respect to the underlying cosmic web spanned by the dark matter field. Using the Bias Assignment Method we find that nonlocal bias plays a central role. We classify the cosmic web based on the invariants of the curvature tensor defined not only by the gravitational potential, but especially by the overdensity, as small-scale clustering becomes important in this context. First, the gas density bias relation can be directly mapped onto the dark matter density field to high precision exploiting the strong correlation between them. In a second step, the neutral hydrogen is mapped based on the dark matter and the gas density fields. Finally, the temperature is mapped based on the previous quantities. This permits us to statistically reconstruct the baryon properties within the same simulated volume finding percent precision in the two-point statistics and compatible results in the three-point statistics, in general within 1σ, with respect to the reference simulation (with 5-6 orders of magnitude less computing time). This paves the path to establish the best setup for the construction of mocks probing the intergalactic medium for the generation of such key ingredients in the statistical analysis of large forthcoming missions such as DESI, Euclid, J-PAS, and WEAVE.

Keywords: cosmology
Hydrogen Recombination Line Luminosities and Variability from Forming Planets

We calculated hydrogen recombination line luminosities (H-α, Paschen-β and Brackett-γ) from 3D thermohydrodynamical simulations of forming planets from 1 to 10 Jupiter mass (MJup). We explored various opacities to estimate the line emissions with extinction, in each case assuming boundary-layer accretion. When realistic opacities are considered, only lines from planets ≥10 MJup can be detected with current instrumentation, highlighting that most planets do not have detectable emission. This might explain the very low detection rate of H-α from forming planets from observations. While the line emission comes from both the forming planet and its circumplanetary disk, we found that only the disk component could be detected due to extinction. We examined the line variability as well, and found that it is higher for higher-mass planets. Furthermore, we determine for the first time the parametric relationship between the mass of the planet and the luminosity of the hydrogen recombination lines, as well as the equation between the accretion luminosity and hydrogen recombination line luminosities.

Keywords: exoplanet detection methods; accretion; photoionization; extrasolar gaseous giant planets; protoplanetary disks
SOFIA upGREAT/FIFI-LS Emission-line Observations of Betelgeuse during the Great Dimming of 2019/2020

We report NASA-DLR SOFIA upGREAT circumstellar [O I] 63.2 μm and [C II] 157.7 μm emission profiles and FIFI-LS [O I] 63.2 μm, [O I] 145.5 μm, and [C II] 157.7 μm fluxes obtained shortly after Betelgeuse's 2019/2020 Great Dimming event. Haas et al. noted a potential correlation between the [O I] 63.2 μm flux and V magnitude based on three Kuiper Airborne Observatory observations made with the CGS and FIFI instruments. The FIFI observation was obtained when V ≃ 0.88 and revealed a 3σ non-detection at a quarter of the previous CGS flux measurement made when V ≃ 0.35. A potential explanation could be a change in dust-gas drag heating by circumstellar silicates caused by variations in the photospheric radiation field. SOFIA observations provide a unique test of this correlation because the V-band brightness went to its lowest value on record, V ≃ 1.61, with the SOFIA observations being made when V FIFI-LS ≃ 1.51 and V upGREAT ≃ 1.36. The upGREAT spectra show a [O I] 63.2 μm flux larger than previous space observatory measurements obtained when V ≃ 0.58. The profile is consistent with formation in the slower, more turbulent inner S1 outflow, while the [C II] 157.7 μm profile is consistent with formation farther out in the faster S2 outflow. Modeling of dust-gas drag heating, combined with 25 yr of Wing three-filter and V photometry, reveals that it is unlikely that the S1 circumstellar envelope and [O I] 63.2 μm fluxes are dominated by the dust-gas drag heating and that another heating source is also active. The [O I] 63.2 μm profile is hard to reconcile with existing outflow velocity models.

Keywords: circumstellar envelopes; stellar mass loss; massive stars; circumstellar dust; far infrared astronomy
On the 3D Curvature and Dynamics of the Musca Filament

Filaments are ubiquitous in the interstellar medium, yet their formation and evolution remain the topic of intense debate. In order to obtain a more comprehensive view of the 3D morphology and evolution of the Musca filament, we model the C18O(2-1) emission along the filament crest with several large-scale velocity field structures. This indicates that Musca is well described by a 3D curved cylindrical filament with longitudinal mass inflow to its center unless the filament is a transient structure with a lifetime ≲0.1 Myr. Gravitational longitudinal collapse models of filaments appear unable to explain the observed velocity field. To better understand these kinematics, we further analyze a map of the C18O(2-1) velocity field at the location of SOFIA HAWC+ dust polarization observations that trace the magnetic field in the filament. This unveils an organized magnetic field that is oriented roughly perpendicular to the filament crest. Although the velocity field is also organized, it progressively changes its orientation by more than 90° when laterally crossing the filament crest and thus appears disconnected from the magnetic field in the filament. This strong lateral change of the velocity field over the filament remains unexplained and might be associated with important longitudinal motion that can be associated to the large-scale kinematics along the filament.

Keywords: interstellar filaments; interstellar medium; interstellar magnetic fields; molecular clouds
2023 Recovery Observations and Characterization of the Active Centaur P/2010 TO20 (LINEAR-Grauer)

We report the recovery of the Centaur P/2010 TO20 (LINEAR-Grauer) on CCD imaging data from three separate dates in 2023 April, May, and June from the 8.1 m Gemini South Telescope, representing its first known detections since 2012. The recovery observations display a compact coma and tail, consistent with ongoing activity after its recent 2022 November 27 perihelion passage. We estimate a nucleus radius upper-limit of r n ≤ 2.7 km. Due to the current uncertainty inherent in the nucleus' true size, we report a plausible range for the dust production of 2.7 cm ≤ Af ρ ≤ 14.5 cm after subtraction of an assumed nucleus flux based on radii of 2.7 km and 0.5 km, respectively. P/2010 TO20 experienced a recent and well-defined orbital change and associated change in thermal environment, making it an exciting target through which to study Centaur activity drivers and their evolution as their orbits change in real-time.

Keywords: centaur group; short period comets
Star Formation and Dust in the Cosmic Web

The large-scale environment of the cosmic web is believed to impact galaxy evolution, but there is still no consensus regarding the mechanisms. We use a semi-analytic model (SAM) galaxy catalog to study the star formation and dust content of local galaxies in different cosmic environments of the cosmic web—namely voids, filaments, walls, and nodes. We find a strong impact of the environment only for galaxies with M stars ≲ 1010.8 M ⊙: the less dense the environment, the larger the star formation rate and dust content at fixed stellar mass. This is attributed to the fact that galaxies in less dense environments typically feature younger stellar populations, a slower evolution of their stellar mass, and delayed star formation compared to galaxies in denser environments. As for galaxies with M stars ≳ 1010.8 M ⊙, the differences among environments are milder, due to the disk-instability-driven supermassive black hole (SMBH) growth implemented in the SAM, which makes SMBH growth, and thus galaxy quenching, environment-insensitive. We qualitatively test our predictions against observations by identifying environments in Sloan Digital Sky Survey Data Release 16 using dust masses derived from the GAMA survey. The agreement is encouraging, particularly at $\mathrm{log}\,{M}_{\mathrm{stars}}/{M}_{\odot }\gtrsim 10.5\mbox{--}11$ , where the specific star formation rates and dust masses appear quite environment-insensitive. This result confirms the importance of in situ growth channels of SMBHs.

Keywords: galaxy evolution; cosmic web; galaxy environments; interstellar medium; interstellar dust; galaxy quenching; supermassive black holes
Modeling of Radio Supernovae: Including the Effects of Inhomogeneities and Radiative Cooling

The presence of inhomogeneities in a spatially unresolved source is often hard to establish. This limits the accuracy with which the source properties can be determined. It is shown how observed features not expected for a homogeneous model can be used to infer the properties of the inhomogeneities in radio supernovae. Furthermore, the observed consequences of radiative cooling can be seriously affected by inhomogeneities. It is shown that the deduced source properties are very sensitive to the observed value of the cooling frequency; even a lower limit is often useful to constrain its characteristics. It is argued that the main synchrotron emission region in SN 2003L has a small volume filling factor, possibly as low as a few percent. On the contrary, deviations from homogeneity are substantially smaller in SN 2002ap. The observed properties of Type Ib/c radio supernovae in general indicate the volume filling factor to remain rather constant with time for individual sources, but those peaking later at radio frequencies have lower filling factors. The conditions in the main synchrotron component in both SN 2003L and SN 2002ap are consistent with equipartition of energy between relativistic electrons and magnetic fields.

Keywords: supernovae; radiative processes; non-thermal radiation sources; magnetic fields; shocks; radio continuum emission
Monitoring AGNs with Hβ Asymmetry. II. Reverberation Mapping of Three Seyfert Galaxies Historically Displaying Hβ Profiles with Changing Asymmetry: Mrk 79, NGC 3227, and Mrk 841

We report the results of reverberation mapping of three bright Seyfert galaxies, Mrk 79, NGC 3227, and Mrk 841, from a campaign conducted from 2016 December to 2017 May with the Wyoming Infrared Observatory (WIRO) 2.3 m telescope. All three of these targets have shown asymmetric broad Hβ emission lines in the past, although their emission lines were relatively symmetric during our observations. We measured Hβ time lags for all three targets and estimated masses of their black holes—for the first time in the case of Mrk 841. For Mrk 79 and NGC 3227, the data are of sufficient quality to resolve distinct time lags as a function of velocity and to compute two-dimensional velocity-delay maps. Mrk 79 shows smaller time lags for high-velocity gas, but the distribution is not symmetric, and its complex velocity-delay map could result from the combination of both inflowing and outflowing Hβ emitting disks that may be part of a single larger structure. NGC 3227 shows the largest time lags for blueshifted gas, and the two-dimensional velocity-delay map suggests a disk with some inflow. We compare our results with previous work and find evidence for different time lags despite similar luminosities, as well as evolving broad-line region structures.

Keywords: seyfert galaxies; supermassive black holes; reverberation mapping
GROWTH on S190814bv: Deep Synoptic Limits on the Optical/Near-infrared Counterpart to a Neutron Star-Black Hole Merger

On 2019 August 14, the Advanced LIGO and Virgo interferometers detected the high-significance gravitational wave (GW) signal S190814bv. The GW data indicated that the event resulted from a neutron star-black hole (NSBH) merger, or potentially a low-mass binary BH merger. Due to the low false-alarm rate and the precise localization (23 deg2 at 90%), S190814bv presented the community with the best opportunity yet to directly observe an optical/near-infrared counterpart to an NSBH merger. To search for potential counterparts, the GROWTH Collaboration performed real-time image subtraction on six nights of public Dark Energy Camera images acquired in the 3 weeks following the merger, covering >98% of the localization probability. Using a worldwide network of follow-up facilities, we systematically undertook spectroscopy and imaging of optical counterpart candidates. Combining these data with a photometric redshift catalog, we ruled out each candidate as the counterpart to S190814bv and placed deep, uniform limits on the optical emission associated with S190814bv. For the nearest consistent GW distance, radiative transfer simulations of NSBH mergers constrain the ejecta mass of S190814bv to be Mej < 0.04 M⊙ at polar viewing angles, or Mej < 0.03 M⊙ if the opacity is κ < 2 cm2g-1. Assuming a tidal deformability for the NS at the high end of the range compatible with GW170817 results, our limits would constrain the BH spin component aligned with the orbital momentum to be χ < 0.7 for mass ratios Q < 6, with weaker constraints for more compact NSs.

Keywords: neutron stars; binary stars; gravitational wave sources; gravitational waves; transient sources; black hole physics; observational astronomy
Hard X-Ray Emission from the Eastern Jet of SS 433 Powering the W50 "Manatee" Nebula: Evidence for Particle Reacceleration

We present a broadband X-ray study of W50 (the "Manatee" nebula), the complex region powered by the microquasar SS 433, that provides a test bed for several important astrophysical processes. The W50 nebula, a Galactic PeVatron candidate, is classified as a supernova remnant but has an unusual double-lobed morphology likely associated with the jets from SS 433. Using NuSTAR, XMM-Newton, and Chandra observations of the inner eastern lobe of W50, we have detected hard nonthermal X-ray emission up to ~30 keV, originating from a few-arcminute-sized knotty region ("Head") located ≲18' (29 pc for a distance of 5.5 kpc) east of SS 433, and constrained its photon index to 1.58 ± 0.05 (0.5-30 keV band). The index gradually steepens eastward out to the radio "ear" where thermal soft X-ray emission with a temperature kT ~ 0.2 keV dominates. The hard X-ray knots mark the location of acceleration sites within the jet and require an equipartition magnetic field of the order of ≳12 μG. The unusually hard spectral index from the "Head" region challenges classical particle acceleration processes and points to particle injection and reacceleration in the subrelativistic SS 433 jet, as seen in blazars and pulsar wind nebulae.

Keywords: supernova remnants; x-ray astronomy; high energy astrophysics; jets
Properties of Host Galaxies of Submillimeter Sources as Revealed by JWST Early Release Observations in SMACS J0723.3-7327

Using the 0.9-4.4 μm imaging data from the James Webb Space Telescope (JWST) early release observation in the SMACS J0723.3-7327 galaxy cluster field, we discuss the properties of three submillimeter galaxies (SMGs) detected by the Atacama Large Millimeter/submillimeter Array Array. These sources are magnified by 1.4-2.1 × due to gravitational lensing. This is the first time that submillimeter galaxy hosts are resolved in the rest-frame near-infrared (NIR). One source was previously undetected by Hubble Space Telescope, while the remaining two are disk galaxies with Sérsic indices of ~0.9 and star formation rates on or just below the star formation "main sequence." Their submillimeter emission originates from the inner parts of the hosts, suggesting that their dust contents are concentrated toward the center. The host half-light radii measured in the rest-frame NIR are ~1.5 × smaller than those measured in the rest-frame optical, consistent with a concentrated dust distribution. The more severe extinction that optical light suffers toward the center makes it seemingly less concentrated. Therefore, we expect that the optically based determination of the stellar mass distribution within host galaxies could still be severely biased by dust. Interestingly, these two disk galaxies are dramatically different in their outer regions, with one being star forming and the other being quiescent. Upcoming JWST observations of statistically significant samples of SMGs will allow us to understand the correlation between the dusty star-forming regions and their hosts.

Keywords: far infrared astronomy; luminous infrared galaxies; high angular resolution; infrared astronomical satellite; infrared telescopes; infrared sources; galaxy clusters
Heuristic Description of Perpendicular Particle Transport in Turbulence with Super-diffusive Magnetic Field Lines

Recently a heuristic description of collisionless perpendicular diffusion of energetic particles was presented. The latter approach describes the transport of energetic particles across a mean magnetic field based on simple physical arguments. Although this approach was developed with the intention to improve our understanding of perpendicular diffusion, this heuristic approach also provided some interesting quantitative results such as an explanation of the factor a2 used in the past to balance out inaccuracies of systematic analytical theories. However, the aforementioned heuristic approach is based on the assumption that magnetic field lines become diffusive after overcoming the initial free-streaming regime. In the current paper we alter the heuristic approach to make it applicable for turbulence spectra leading to super-diffusive magnetic fields lines. It is argued that particle diffusion is still restored in the late time limit. In the high-energy limit this recovery of diffusion is based on a hybrid model in which particles move half ballistically and half diffusively in the parallel direction. Furthermore, this leads to the relation ${\lambda }_{\perp }\propto {\lambda }_{\parallel }^{1/3}$ between perpendicular and parallel mean free paths of the energetic particles. This type of transport was obtained in the past from test-particle simulations as well as systematic analytical theories. In the current paper we present the first time an explanation of this behavior based on simple physical arguments.

Keywords: interplanetary turbulence; galactic cosmic rays; solar energetic particles
Progenitor Dependence of Hadron-quark Phase Transition in Failing Core-collapse Supernovae

We study the consequences of a hadron-quark phase transition (PT) in failing core-collapse supernovae (CCSNe) that give birth to stellar-mass black holes (BH). We perform a suite of neutrino-transport general-relativistic hydrodynamic simulations in spherical symmetry with 21 progenitor models and a hybrid equation of state (EoS) including hadrons and quarks. We find that the effect of the PT on the CCSN postbounce dynamics is a function of the bounce compactness parameter ${\xi }_{2.2}$ . For ${\xi }_{2.2}\gtrsim 0.24$ , the PT leads to a second dynamical collapse of the protocompact star (PCS). While BH formation starts immediately after this second collapse for models with ${\xi }_{2.2}\gtrsim 0.51$ , the PCS experiences a second bounce and oscillations for models with $0.24\lesssim {\xi }_{2.2}\lesssim 0.51$ . These models emit potent oscillatory neutrino signals with a period of ∼1 ms for tens of milliseconds after the second bounce, which can be a strong indicator of the PT in failing CCSNe if detected in the future. However, no shock revival occurs and BH formation inevitably takes place in our spherically symmetric simulations. Furthermore, via a diagram of mass-specific entropy evolution of the PCS, the progenitor dependence can be understood through the appearance of a third family of compact stars emerging at large entropy induced by the PT.

Keywords: core-collapse supernovae; supernova neutrinos; stellar mass black holes; nuclear astrophysics
Dynamics of Laterally Propagating Flames in X-Ray Bursts. I. Burning Front Structure

We investigate the structure of laterally propagating flames through the highly stratified burning layer in an X-ray burst. Two-dimensional hydrodynamics simulations of flame propagation are performed through a rotating plane-parallel atmosphere, exploring the structure of the flame. We discuss the approximations needed to capture the length and timescales at play in an X-ray burst and describe the flame acceleration observed. Our studies complement other multidimensional studies of burning in X-ray bursts.

Keywords: x-ray bursts; nucleosynthesis; open source software; hydrodynamics; computational methods; hydrodynamical simulations; neutron stars; nuclear astrophysics
Katachi (形): Decoding the Imprints of Past Star Formation on Present-day Morphology in Galaxies with Interpretable CNNs

The physical processes responsible for shaping how galaxies form and quench over time leave imprints on both the spatial (galaxy morphology) and temporal (star formation history; SFH) tracers that we use to study galaxies. While the morphology–SFR connection is well studied, the correlation with past star formation activity is not as well understood. To quantify this, we present Katachi (形), an interpretable convolutional neural network framework that learns the connection between the factors regulating star formation in galaxies on different spatial and temporal scales. Katachi is trained on 9904 galaxies at 0.02 < z < 0.1 in the SDSS-IV MaNGA DR17 sample to predict stellar mass (M *; root mean square error (RSME) 0.22 dex), current star formation rate (SFR; RMSE 0.31 dex), and half-mass time (t 50; RMSE 0.23 dex). This information allows us to reconstruct nonparametric SFHs for each galaxy from gri imaging alone. To quantify the morphological features informing the SFH predictions, we use SHAP (SHapley Additive exPlanations). We recover the expected trends of M * governed by the growth of galaxy bulges, as well as those of SFR correlating with spiral arms and other star-forming regions. We also find that the SHAP maps of D4000 are more complex than those of M * and SFR, and that morphology is correlated with t 50 even at fixed mass and SFR. Katachi serves as a scalable public framework to predict galaxy properties from large imaging surveys including Rubin, Roman, and Euclid, with large data sets of high signal-to-noise ratio imaging across limited photometric bands. * https://github.com/juanpabloalfonzo/Katachi

Keywords: extragalactic astronomy; galaxy classification systems; galaxy evolution; astronomy data analysis; convolutional neural networks