Sazuna/UAT_keywords huggingface dataset:
The S-Web Origin of Composition Enhancement in the Slow-to-moderate Speed Solar Wind. Connecting the solar wind observed throughout the heliosphere to its origins in the solar corona is one of the central aims of heliophysics. The variability in the magnetic field, bulk plasma, and heavy ion composition properties of the slow wind are thought to result from magnetic reconnection processes in the solar corona. We identify regions of enhanced variability and composition in the solar wind from 2003 April 15 to May 13 (Carrington Rotation 2002), observed by the Wind and Advanced Composition Explorer spacecraft, and demonstrate their relationship to the separatrix-web (hereafter, S-Web) structures describing the corona's large-scale magnetic topology. There are four pseudostreamer (PS) wind intervals and two helmet streamer (HS) heliospheric current sheet/plasma sheet crossings (and an interplanetary coronal mass ejection), which all exhibit enhanced alpha-to-proton ratios and/or elevated ionic charge states of carbon, oxygen, and iron. We apply the magnetic helicity-partial variance of increments (H  m -PVI) procedure to identify coherent magnetic structures and quantify their properties during each interval. The mean duration of these structures are ~1 hr in both the HS and PS wind. We find a modest enhancement above the power-law fit to the PVI waiting-time distribution in the HS-associated wind at the 1.5-2 hr timescales that is absent from the PS intervals. We discuss our results in the context of previous observations of the ~90 minutes periodic density structures in the slow solar wind, further development of the dynamic S-Web model, and future Parker Solar Probe and Solar Orbiter joint observational campaigns.

Keywords: Slow solar wind, Space plasmas, Solar magnetic reconnection, Heliosphere, Interplanetary turbulence, Solar physics, Solar magnetic fields
Predicting Short-duration GRB Rates in the Advanced LIGO Volume. Starting with models for the compact object merger event rate, the short-duration gamma-ray burst (sGRB) luminosity function, and the Swift-BAT detector, we calculate the observed Swift sGRB rate and its uncertainty. Our probabilistic sGRB world model reproduces the observed number distributions in redshift and flux for 123 Swift-BAT detected sGRBs and can be used to predict joint sGRB/LIGO detection rates. We discuss the dependence of the rate predictions on the model parameters and explore how they vary with increasing experimental sensitivity. In particular, the number of bursts in the LIGO volume depends strongly on the parameters that govern sGRB beaming. Our results suggest that nearby sGRBs should be observed to have broader jets on average (θ jet ≳ 30°), as compared to the narrowly beamed appearance of cosmological sGRBs due to the detection-selection effect driving the observed jet angle. Assuming all sGRBs are due to compact object mergers, within a D &lt; 200 Mpc aLIGO volume, we predict ${0.18}_{-0.08}^{+0.19}$ sGRB-gravitational wave (GW) associations all sky per year for on-axis events at Swift sensitivities, increasing to ${1.2}_{-0.6}^{+1.9}$ with the inclusion of off-axis events. We explore the consistency of our model with GW170817/GRB 170817A in the context of structured jets. Predictions for future experiments are made.

Keywords: Gamma-ray bursts, Gravitational wave sources, Gravitational waves, LIGO, Gamma-rays
Diffuse Emission of Galactic High-energy Neutrinos from a Global Fit of Cosmic Rays. In the standard picture of Galactic cosmic rays, a diffuse flux of high-energy gamma rays and neutrinos is produced from inelastic collisions of cosmic-ray nuclei with the interstellar gas. The neutrino flux is a guaranteed signal for high-energy neutrino observatories such as IceCube but has not been found yet. Experimental searches for this flux constitute an important test of the standard picture of Galactic cosmic rays. Both observation and nonobservation would allow important implications for the physics of cosmic-ray acceleration and transport. We present CRINGE, a new model of Galactic diffuse high-energy gamma rays and neutrinos, fitted to recent cosmic-ray data from AMS-02, DAMPE, IceTop, as well as KASCADE. We quantify the uncertainties for the predicted emission from the cosmic-ray model but also from the choice of source distribution, gas maps, and cross sections. We consider the possibility of a contribution from unresolved sources. Our model predictions exhibit significant deviations from older models. Our fiducial model is available at https://doi.org/10.5281/zenodo.7859442 .

Keywords: Diffuse radiation, Gamma-ray astronomy, Neutrino astronomy, Galactic cosmic rays
Explosion Mechanism of Core-collapse Supernovae: Role of the Si/Si-O Interface. We present a simple criterion to predict the explodability of massive stars based on the density and entropy profiles before collapse. If a pronounced density jump is present near the Si/Si-O interface, the star will likely explode. We develop a quantitative criterion by using ~1300 1D simulations where ν-driven turbulence is included via time-dependent mixing-length theory. This criterion correctly identifies the outcome of the supernova more than 90% of the time. We also find no difference in how this criterion performs on two different sets of progenitors, evolved using two different stellar evolution codes: FRANEC and KEPLER. The explodability as a function of mass of the two sets of progenitors is very different, showing: (i) that uncertainties in the stellar evolution prescriptions influence the predictions of supernova explosions; (ii) the most important properties of the pre-collapse progenitor that influence the explodability are its density and entropy profiles. We highlight the importance that ν-driven turbulence plays in the explosion by comparing our results to previous works.

Keywords: Supernova neutrinos, Supernova dynamics, Core-collapse supernovae, Massive stars, Gravitational collapse, Supernovae
Stellar Populations in the Central 0.5 pc of Our Galaxy. III. The Dynamical Substructures. We measure the 3D kinematic structures of the young stars within the central 0.5 pc of our Galactic Center using the 10 m telescopes of the W. M. Keck Observatory over a time span of 25 yr. Using high-precision measurements of positions on the sky and proper motions and radial velocities from new observations and the literature, we constrain the orbital parameters for each young star. Our results show two statistically significant substructures: a clockwise stellar disk with 18 candidate stars, as has been proposed before, but with an improved disk membership; and a second, almost edge-on plane of 10 candidate stars oriented east-west on the sky that includes at least one IRS 13 star. We estimate the eccentricity distribution of each substructure and find that the clockwise disk has &lt;e&gt; = 0.39 and the edge-on plane has &lt;e&gt; = 0.68. We also perform simulations of each disk/plane with incompleteness and spatially variable extinction to search for asymmetry. Our results show that the clockwise stellar disk is consistent with a uniform azimuthal distribution within the disk. The edge-on plane has an asymmetry that cannot be explained by variable extinction or incompleteness in the field. The orientation, asymmetric stellar distribution, and high eccentricity of the edge-on plane members suggest that this structure may be a stream associated with the IRS 13 group. The complex dynamical structure of the young nuclear cluster indicates that the star formation process involved complex gas structures and dynamics and is inconsistent with a single massive gaseous disk.

Keywords: Galactic center, Astrometry, High angular resolution, Infrared observatories
Can Protostellar Outflows Set Stellar Masses?. The opening angles of some protostellar outflows appear too narrow to match the expected core-star mass efficiency (SFE) = 0.3-0.5, if the outflow cavity volume traces outflow mass, with a conical shape and a maximum opening angle near 90°. However, outflow cavities with a paraboloidal shape and wider angles are more consistent with observed estimates of the SFE. This paper presents a model of infall and outflow evolution based on these properties. The initial state is a truncated singular isothermal sphere which has mass ≈ 1 M ⊙, freefall time ≈ 80 kyr, and small fractions of magnetic, rotational, and turbulent energy. The core collapses pressure free as its protostar and disk launch a paraboloidal wide-angle wind. The cavity walls expand radially and entrain envelope gas into the outflow. The model matches the SFE values when the outflow mass increases faster than the protostar mass by a factor 1-2, yielding protostar masses typical of the IMF. It matches the observed outflow angles if the outflow mass increases at nearly the same rate as the cavity volume. The predicted outflow angles are then typically ~50° as they increase rapidly through the stage 0 duration of ~40 kyr. They increase more slowly up to ~110° during their stage I duration of ~70 kyr. With these outflow rates and shapes, the model predictions appear consistent with observational estimates of the typical stellar masses, SFEs, stage durations, and outflow angles, with no need for external mechanisms of core dispersal.

Keywords: Protostars, Stellar winds, Star formation
Correlation Analysis between OJ 287 Radio Jet Observables. We collected the archival data of blazar OJ 287 from heterogeneous very long baseline interferometry monitoring programs at 2.3, 8.6, 15, and 43 GHz. The data reduction and observable extraction of those multiband, multiepoch observations are batch-processed consistently with our automated pipeline. We present the multivariate correlation analysis on the observables at each band. We employ the cross-correlation function to search the correlations and the Monte Carlo technique to verify the certainty of correlations. Several correlations are found. The foremost findings are the correlations between the core flux density and the jet position angles on different scales, which validated the plausible predictions of the jet with precession characteristics. Meanwhile, there is a variation in the offset between the core electric vector position angle and the inner-jet position angle over time at 15 and 43 GHz.

Keywords: Radio jets, Blazars, Very long baseline interferometry, Relativistic jets, Relativistic aberration, Active galactic nuclei
Regulation of Star Formation by a Hot Circumgalactic Medium. Galactic outflows driven by supernovae (SNe) are thought to be a powerful regulator of a galaxy's star-forming efficiency. Mass, energy, and metal outflows (η  M , η  E , and η  Z , here normalized by the star formation rate, the SNe energy, and metal production rates, respectively) shape galaxy properties by both ejecting gas and metals out of the galaxy and by heating the circumgalactic medium (CGM), preventing future accretion. Traditionally, models have assumed that galaxies self-regulate by ejecting a large fraction of the gas, which enters the interstellar medium (ISM), although whether such high mass loadings agree with observations is still unclear. To better understand how the relative importance of ejective (i.e., high mass loading) versus preventative (i.e., high energy loading) feedback affects the present-day properties of galaxies, we develop a simple gas-regulator model of galaxy evolution, where the stellar mass, ISM, and CGM are modeled as distinct reservoirs which exchange mass, metals, and energy at different rates within a growing halo. Focusing on the halo mass range from 1010 to 1012 M ⊙, we demonstrate that, with reasonable parameter choices, we can reproduce the stellar-to-halo mass relation and the ISM-to-stellar mass relation with low-mass-loaded (η  M  ~ 0.1-10) but high-energy-loaded (η  E  ~ 0.1-1) winds, with self-regulation occurring primarily through heating and cooling of the CGM. We show that the model predictions are robust against changes to the mass loading of outflows but are quite sensitive to our choice of the energy loading, preferring η  E  ~ 1 for the lowest-mass halos and ~0.1 for Milky Way-like halos.

Keywords: Galactic winds, Galaxy physics, Galactic and extragalactic astronomy, Galaxy evolution, Circumgalactic medium, Galaxies
The Hα Broadband Photometric Reverberation Mapping of Four Seyfert 1 Galaxies. Broadband photometric reverberation mapping (PRM) has been investigated for active galactic nuclei (AGNs) in recent years, but mostly on accretion disk continuum RM. Due to the small fraction of broad emission lines in the broad band, PRM for emission lines is very challenging. Here, we present an ICCF-Cut method for broadband PRM to obtain the Hα broad-line lag and apply it to four Seyfert 1 galaxies: MCG+08-11-011, NGC 2617, 3C 120, and NGC 5548. All of them have high-quality broadband lightcurves with daily/subdaily cadences, which enable us to extract Hα lightcurves from the line band by subtracting the contributions from the continuum and host galaxy. Their extracted Hα lightcurves are compared with the lagged continuum-band lightcurves, as well as the lagged Hβ lightcurves obtained by spectroscopic RM (SRM) at the same epochs. The consistency of these lightcurves and the comparison with the SRM Hβ lags provide support for the Hα lags of these AGNs, in a range from 9 to 19 days, obtained by the ICCF-Cut, JAVELIN, and χ 2 methods. The simulations for evaluating the reliability of the Hα lags and the comparisons between the SRM Hβ and PRM Hα lags indicate that the consistency of the ICCF-Cut, JAVELIN, and χ 2 results can ensure the reliability of the derived Hα lags. These methods may be used to estimate the broad-line region sizes and black hole masses of a large sample of AGNs in large multi-epoch, high-cadence photometric surveys such as LSST in the future.

Keywords: Reverberation mapping, Seyfert galaxies, Active galactic nuclei
SN 2017egm: A Helium-rich Superluminous Supernova with Multiple Bumps in the Light Curves. When discovered, SN 2017egm was the closest (redshift z = 0.03) hydrogen-poor superluminous supernova (SLSN-I) and a rare case that exploded in a massive and metal-rich galaxy. Thus, it has since been extensively observed and studied. We report spectroscopic data showing strong emission at around He I λ10830 and four He I absorption lines in the optical. Consequently, we classify SN 2017egm as a member of an emerging population of helium-rich SLSNe-I (i.e., SLSNe-Ib). We also present our late-time photometric observations. By combining them with archival data, we analyze high-cadence ultraviolet, optical, and near-infrared light curves spanning from early pre-peak (~-20 days) to late phases (~+300 days). We obtain its most complete bolometric light curve, in which multiple bumps are identified. None of the previously proposed models can satisfactorily explain all main light-curve features, while multiple interactions between the ejecta and circumstellar material (CSM) may explain the undulating features. The prominent infrared excess with a blackbody luminosity of 107-108 L ⊙ detected in SN 2017egm could originate from the emission of either an echo of a pre-existing dust shell or newly formed dust, offering an additional piece of evidence supporting the ejecta-CSM interaction model. Moreover, our analysis of deep Chandra observations yields the tightest-ever constraint on the X-ray emission of an SLSN-I, amounting to an X-ray-to-optical luminosity ratio ≲10-3 at late phases (~100-200 days), which could help explore its close environment and central engine.

Keywords: Supernovae
Dynamics of Two-dimensional Type III Electron Beams in Randomly Inhomogeneous Solar Wind Plasmas. The dynamics of a type III electron beam generating Langmuir wave turbulence and subsequent electromagnetic emissions is studied owing to two-dimensional Particle-In-Cell simulations performed in both homogeneous and randomly inhomogeneous solar wind plasmas. Important differences in the beam dynamics are highlighted between both cases, due to Langmuir waves' transformations on the density fluctuations. This paper studies the dynamics of a weak beam interacting with Langmuir wave turbulence scattered by initially applied plasma density fluctuations, in terms of particle acceleration, non-Gaussian suprathermal electron tails, broadening and relaxation of velocity distributions, beam density localization, and electron diffusion or trapping in a turbulent plasma. Density fluctuations are the cause of beam acceleration during its relaxation stage; after Langmuir wave saturation, it gains up to half the energy lost during deceleration while wave turbulence is damping, exhibiting asymptotically a suprathermal tail of electrons carrying around 30% of its initial kinetic energy. Some important features observed for one-dimensional beams exciting Langmuir wave turbulence in randomly inhomogeneous plasmas can be recovered.

Keywords: Solar electromagnetic emission
WALLABY Pilot Survey: H I in the Host Galaxy of a Fast Radio Burst. We report on the commensal ASKAP detection of a fast radio burst (FRB), FRB 20211127I, and the detection of neutral hydrogen (H I) emission in the FRB host galaxy, WALLABY J131913-185018 (hereafter W13-18). This collaboration between the CRAFT and WALLABY survey teams marks the fifth, and most distant, FRB host galaxy detected in H I, not including the Milky Way. We find that W13-18 has an H I mass of M HI = 6.5 × 109 M ☉, an H I-to-stellar mass ratio of 2.17, and coincides with a continuum radio source of flux density at 1.4 GHz of 1.3 mJy. The H I global spectrum of W13-18 appears to be asymmetric, albeit the H I observation has a low signal-to-noise ratio (S/N), and the galaxy itself appears modestly undisturbed. These properties are compared to the early literature of H I emission detected in other FRB hosts to date, where either the H I global spectra were strongly asymmetric, or there were clearly disrupted H I intensity map distributions. W13-18 lacks a sufficient S/N to determine whether it is significantly less asymmetric in its H I distribution than previous examples of FRB host galaxies. However, there are no strong signs of a major interaction in the optical image of the host galaxy that would stimulate a burst of star formation and hence the production of putative FRB progenitors related to massive stars and their compact remnants.

Keywords: Radio transient sources, Galaxy mergers, H I line emission
X-Ray Spectroscopy of Interstellar Carbon: Evidence for Scattering by Carbon-bearing Material in the Spectrum of 1ES 1553+113. Molecules and particles make up ~40%-70% of carbon in the interstellar medium, yet the exact chemical structure of these constituents remains unknown. We present carbon K-shell absorption spectroscopy of the Galactic interstellar medium obtained with the Low Energy Transmission Grating Spectrometer on board the Chandra Observatory that directly addresses this question. We probe several lines of sight, using bright active galactic nuclei as backlighters. We make our measurements differentially with respect to the bright source Mrk 421, in order to take the significant carbon K absorption in the instrument into account. In the spectrum of the blazar 1ES 1553+113 we find evidence for a novel feature: strong extinction on the low-energy side of the neutral C 1s-2p resonance, which is indicative of scattering by graphite particles. We find evidence for characteristic particle radii of order 0.1-0.15 μm. If this explanation for the feature is correct, limits on the mass of the available carbon along the line of sight may imply that the grains are partially aligned, and the X-rays from the source may have intrinsic polarization.

Keywords: Interstellar medium, Active galactic nuclei, Carbonaceous grains, Spectroscopy
A Large Double-ring Disk Around the Taurus M Dwarf J04124068+2438157. Planet formation imprints signatures on the physical structures of disks. In this paper, we present high-resolution (~50 mas, 8 au) Atacama Large Millimeter/submillimeter Array observations of 1.3 mm dust continuum and CO line emission toward the disk around the M3.5 star 2MASS J04124068+2438157. The dust disk consists of only two narrow rings at radial distances of 0.″47 and 0.″78 (~70 and 116 au), with Gaussian σ widths of 5.6 and 8.5 au, respectively. The width of the outer ring is smaller than the estimated pressure scale height by ~25%, suggesting dust trapping in a radial pressure bump. The dust disk size, set by the location of the outermost ring, is significantly larger (by 3σ) than other disks with similar millimeter luminosity, which can be explained by an early formation of local pressure bump to stop radial drift of millimeter dust grains. After considering the disk's physical structure and accretion properties, we prefer planet-disk interaction over dead zone or photoevaporation models to explain the observed dust disk morphology. We carry out high-contrast imaging at the $L^{\prime} $ band using Keck/NIRC2 to search for potential young planets, but do not identify any source above 5σ. Within the dust gap between the two rings, we reach a contrast level of ~7 mag, constraining the possible planet below ~2-4 M Jup. Analyses of the gap/ring properties suggest that an approximately Saturn-mass planet at ~90 au is likely responsible for the formation of the outer ring, which can potentially be revealed with JWST.

Keywords: Planetary system formation, Coronagraphic imaging, Planetary-disk interactions, Protoplanetary disks
Correlation between Emission-line Luminosity and Gamma-Ray Dominance in the Blazar 3C 279. Despite numerous studies, the origin of the γ-ray emission from blazars is still debated, in particular whether it is produced by leptonic or hadronic processes. In this study, we are testing the leptonic scenario for the flat-spectrum radio quasar 3C 279, assuming that the γ-ray emission is generated by inverse Compton scattering of external target photons from the broad-line region (IC-BLR scenario). For this purpose we use a 10 yr data set of the source consisting of the optical spectroscopy data from the Steward Observatory blazar monitoring program and Fermi Large Area Telescope γ-ray data. We search for a possible correlation between the Compton dominance and the emission-line luminosity using the discrete correlation function analysis. As a result, we find no significant correlation between these two quantities at any time lag value, while the emission-line luminosity displays a moderate correlation with the γ-ray flux at a zero time lag. We also reveal that the optical synchrotron continuum flux shows a pronounced correlation with the γ-ray flux, and therefore we interpret these results within the leptonic IC-BLR scenario where the variations in Compton dominance are primarily induced by changes in the magnetic field, rather than in the emission-line luminosity.

Keywords: Blazars, Flat-spectrum radio quasars, Active galactic nuclei