Sazuna/UAT_keywords huggingface dataset:
On the Random Motion of Nuclear Objects in a Fuzzy Dark Matter Halo. Fuzzy dark matter (FDM), consisting of ultralight bosons ( ${m}_{{\rm{b}}}\sim {10}^{-22}\,\,\mathrm{eV}$ ), is an intriguing alternative to cold dark matter. Numerical simulations that solve the Schrödinger-Poisson (SP) equation show that FDM halos consist of a central solitonic core, which is the ground state of the SP equation, surrounded by an envelope of interfering excited states. These excited states also interfere with the soliton, causing it to oscillate and execute a confined random walk with respect to the halo center of mass. Using high-resolution numerical simulations of a $6.6\times {10}^{9}\,\,{M}_{\odot }$ FDM halo with ${m}_{{\rm{b}}}=8\times {10}^{-23}\,\,\mathrm{eV}$ in isolation, we demonstrate that the wobbling, oscillating soliton gravitationally perturbs nuclear objects, such as supermassive black holes or dense star clusters, causing them to diffuse outwards. In particular, we show that, on average, objects with mass ≲0.3% of the soliton mass ( ${M}_{\mathrm{sol}}$ ) are expelled from the soliton in ~3 $\,\mathrm{Gyr}$ , after which they continue their outward diffusion due to gravitational interactions with the soliton and the halo granules. More massive objects (≳ $1 \% \,{M}_{\mathrm{sol}}$ ), while executing a random walk, remain largely confined to the soliton due to dynamical friction. We also present an effective treatment of the diffusion, based on kinetic theory, that accurately reproduces the outward motion of low-mass objects and briefly discuss how the observed displacements of star clusters and active galactic nuclei from the centers of their host galaxies can be used to constrain FDM.

Keywords: Galaxy dark matter halos, Supermassive black holes, Galaxy dynamics, Galaxy nuclei, Gravitational interaction, Dynamical friction
Cross-match between the Latest Swift-BAT and Fermi-LAT Catalogs. We report the results of a cross-match study between the hard X-ray and GeV gamma-ray catalogs, by making use of the latest 105 month Swift-Burst Alert Telescope (BAT) and 10 yr Fermi-Large Area Telescope (LAT) catalogs, respectively. The spatial cross-matching between the two catalogs results in the matching of 132 point-like sources, including ~5% of false-match sources. Additionally, 24 sources that have been identified as the same identifications are matched. Among the 75 extended sources in the Fermi-LAT catalog, 31 sources have spatial coincidences with at least one Swift-BAT source inside their extent. All the matched sources consist of blazars (&gt;60%), pulsars and pulsar wind nebulae (~13%), radio galaxies (~7%), binaries (~5%), and others. Compared to the original catalogs, the matched sources are characterized by a double-peaked photon index distribution, higher flux, and larger gamma-ray variability index. This difference arises from the different populations of sources, particularly the large proportion of blazars (i.e., flat-spectrum radio quasar and BL Lac). We also report 13 cross-matched and unidentified sources. The matched sources in this study would be promising in the intermediate energy band between the hard X-ray and GeV gamma-ray observations, that is the unexplored MeV gamma-ray domain.

Keywords: Gamma-ray sources, X-ray sources, Active galactic nuclei, Catalogs
Trajectory Analysis of Galactic Cosmic Rays Invading into the Heliosphere. The trajectories of galactic cosmic-ray protons invading the heliosphere are investigated by using numerical simulations. A time stationary global heliosphere is first reproduced by using a high-resolution MHD simulation. Then, motions of a number of test particles (protons) distributed in the virtual heliosphere are numerically solved. When the initial particle Lorentz factor is 10 (~10 GeV), the motions of particles are strongly affected by small-scale heliospheric structures reflecting the small gyroradii of the particles. Particles can enter the heliosphere from many parts (nose, flank, and tail) of the heliopause. Once they have entered, they expand in the region where the magnetic field is locally weak, such as the heliopause and the heliospheric current sheet. On the other hand, particles have difficulty invading upstream of the termination shock. We found a variety of invading particle trajectory patterns such as current sheet drift, polar drift, spiral motion, shock drift, and Fermi-like acceleration. In the latter two, particles are accelerated. When the initial particle Lorentz factor is 1000 (~1 TeV), the particles are insensitive to the small-scale structures of the heliosphere due to their large gyroradii. Some particles show eccentric motions due to resonant interaction with the large-scale eddy in the heliotail. Some other particles passing by the heliosphere are mirror reflected due to the bottleneck structure of interstellar magnetic field surrounding the heliosphere and return back to enter the heliosphere.

Keywords: Heliosphere, Solar wind, Galactic cosmic rays, Magnetic fields, Cosmic rays
Linear and Nonlinear Effects of Proton Temperature Anisotropy on Proton-beam Instability in the Solar Wind. Solar wind observations have shown that the drift velocity of the proton beam relative to the background proton is of the order of the local Alfvén velocity. The proton-beam instability has been suggested to play an important role in decelerating proton beams. Most existing studies examined the kinetic properties of the proton-beam instability in simple Maxwellian or drift-Maxwellian plasmas. In this paper, we systemically investigate the effects of the proton temperature anisotropy on the growth rates of proton-beam instabilities using linear Vlasov equations and the nonlinear evolution of these instabilities at different propagation angles using 1D and 2D hybrid simulations. The results show that the real frequencies, growth rates, and threshold conditions strongly depend on the proton temperature anisotropy ${T}_{i\perp }/{T}_{i| | }$ and the parallel proton beta ${\beta }_{i| | }$ . The parallel magnetosonic/whistler (M/W), backward M/W, and oblique Alfvén/ion-cyclotron (A/IC) instabilities are likely to grow in the regime of ${T}_{i\perp }/{T}_{i| | }\lt 1$ , whereas the parallel M/W, oblique A/IC, parallel A/IC, and mirror instabilities tend to be excited in the regime of ${T}_{i\perp }/{T}_{i| | }\gt 1$ . Moreover, the oblique A/IC instability with a linear wave growth phase can quickly reduce the proton-beam drift velocity when ${T}_{i\perp }/{T}_{i| | }\lt 1$ , while the nonlinear wave-particle interaction for the parallel A/IC and mirror instabilities tends to gradually reduce the drift velocity when ${T}_{i\perp }/{T}_{i| | }\gt 1$ . The linear and nonlinear evolution of the proton-beam instability associated with the proton temperature anisotropy can be used to explain the observed dependence of the proton-beam drift velocity on the plasma beta and temperature anisotropy in the solar wind.

Keywords: Space plasmas, Solar wind, Alfven waves
Radiative Driving of the AGN Outflows in the Narrow-line Seyfert 1 Galaxy NGC 4051. We explore the properties of ionized gas in the nuclear and circumnuclear environment of the narrow-line Seyfert 1 galaxy NGC 4051 using spectroscopic and imaging observations from the Hubble Space Telescope (HST) and Apache Point Observatory's ARC 3.5 m Telescope. We identify an unresolved moderate-density intermediate-width component and a high-density broad component in the optical emission lines from the active nucleus, as well as spatially resolved emission extending up to ~1 kpc in the active galactic nucleus (AGN) ionized narrow-line region (NLR) and ~8 kpc in the stellar ionized host galaxy. The HST narrowband image reveals a distinct conical structure in [O III] emission toward the NE, and the ionized gas kinematics shows up to two blueshifted velocity components, indicating outflows along the edges of a cone. We introduce an improved model of biconical outflow, with our line of sight passing through the wall of the cone, which suggests that the large number of outflowing UV absorbers seen in NGC 4051 are NLR clouds in absorption. Using the deprojection factors from the biconical geometry, we measure true outflow velocities up to 680 km s-1 at a distance of ~350 pc; however, we do not find any rotational signature inside a projected distance of $\leqslant $ 10″ (~800 pc) from the nucleus. We compare the gas kinematics with analytical models based on a radiation-gravity formalism, which show that most of the observed NLR outflows are launched within ~0.5 pc of the nucleus and can travel up to ~1 kpc from this low-luminosity AGN. * Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program Nos. 8253, 12212. † Based in part on observations obtained with the Apache Point Observatory 3.5 m telescope, which is owned and operated by the Astrophysical Research Consortium.

Keywords: AGN host galaxies, Supermassive black holes, Active galaxies, Emission line galaxies, Seyfert galaxies, Active galactic nuclei, Galaxy winds, Galaxy kinematics
X-Ray Superflares from Pre-main-sequence Stars: Flare Energetics and Frequency. Solar-type stars exhibit their highest levels of magnetic activity during their early convective pre-main-sequence (PMS) phase of evolution. The most powerful PMS flares, superflares and megaflares, have peak X-ray luminosities of $\mathrm{log}({L}_{{\rm{X}}})=30.5\mbox{-}34.0$ erg s-1 and total energies $\mathrm{log}({E}_{{\rm{X}}})=34\mbox{-}38$ erg. Among &gt;24,000 X-ray-selected young (t ≲ 5 Myr) members of 40 nearby star-forming regions from our earlier Chandra MYStIX and SFiNCs surveys, we identify and analyze a well-defined sample of 1086 X-ray superflares and megaflares, the largest sample ever studied. Most are considerably more powerful than optical/X-ray superflares detected on main-sequence stars. This study presents energy estimates of these X-ray flares and the properties of their host stars. These events are produced by young stars of all masses over evolutionary stages ranging from protostars to diskless stars, with the occurrence rate positively correlated with stellar mass. Flare properties are indistinguishable for disk-bearing and diskless stars indicating star-disk magnetic fields are not involved. A slope of α ≃ 2 in the flare energy distributions ${dN}/{{dE}}_{{\rm{X}}}\propto {E}_{{\rm{X}}}^{-\alpha}$ is consistent with that of optical/X-ray flaring from older stars and the Sun. Megaflares ($\mathrm{log}({E}_{{\rm{X}}})\gt 36.2$ erg) from solar-mass stars have an occurrence rate of ${1.7}_{-0.6}^{+1.0}$ flares/star/year and contribute at least 10%-20% to the total PMS X-ray energetics. These explosive events may have important astrophysical effects on protoplanetary disk photoevaporation, ionization of disk gas, production of spallogenic radionuclides in disk solids, and hydrodynamic escape of young planetary atmospheres. Our following paper details plasma and magnetic loop modeling of the &gt;50 brightest X-ray megaflares.

Keywords: Stellar x-ray flares, Planetary atmospheres, Pre-main sequence stars, Protoplanetary disks, Protostars, X-ray stars
Milky Way Mid-Infrared Spitzer Spectroscopic Extinction Curves: Continuum and Silicate Features. We measured the mid-infrared (MIR) extinction using Spitzer photometry and spectroscopy (3.6-37 μm) for a sample of Milky Way sight lines (mostly) having measured ultraviolet extinction curves. We used the pair method to determine the MIR extinction that we then fit with a power law for the continuum and modified Drude profiles for the silicate features. We derived 16 extinction curves having a range of A(V) (1.8-5.5) and R(V) values (2.4-4.3). Our sample includes two dense sight lines that have 3 μm ice feature detections and weak 2175 Å bumps. The average A(λ)/A(V) diffuse sight-line extinction curve we calculate is lower than most previous literature measurements. This agrees better with literature diffuse dust grain models, though it is somewhat higher. The 10 μm silicate feature does not correlate with the 2175 Å bump, for the first time providing direct observational confirmation that these two features arise from different grain populations. The strength of the 10 μm silicate feature varies by ~2.5 and is not correlated with A(V) or R(V). It is well fit by a modified Drude profile with strong correlations seen between the central wavelength, width, and asymmetry. We do not detect other features with limits in A(λ)/A(V) units of 0.0026 (5-10 μm), 0.004 (10-20 μm), and 0.008 (20-40 μm). We find that the standard prescription of estimating R(V) from C × E(Ks - V)/E(B - V) has C = -1.14 and a scatter of ~7%. Using the IRAC 5.6 μm band instead of Ks gives C = -1.03 and the least scatter of ~3%.

Keywords: Interstellar dust, Silicate grains, Ultraviolet extinction, Interstellar dust extinction
Building Robust Active Galactic Nuclei Mock Catalogs to Unveil Black Hole Evolution and for Survey Planning. The statistical distributions of active galactic nuclei (AGNs), i.e., accreting supermassive black holes (BHs), in mass, space, and time are controlled by a series of key properties, namely, the BH-galaxy scaling relations, Eddington ratio distributions, and fraction of active BH (duty cycle). Shedding light on these properties yields strong constraints on the AGN triggering mechanisms while providing a clear baseline to create useful mock catalogs for the planning of large galaxy surveys. Here we delineate a robust methodology to create mock AGN catalogs built on top of large N-body dark matter simulations via state-of-the-art semiempirical models. We show that by using as independent tests the AGN clustering at fixed X-ray luminosity, galaxy stellar mass, and BH mass, along with the fraction of AGNs in groups and clusters, it is possible to significantly narrow down the choice in the relation between BH mass and host galaxy stellar mass, the duty cycle, and the average Eddington ratio distribution, delivering well-suited constraints to guide cosmological models for the coevolution of BHs and galaxies. Avoiding such a step-by-step methodology inevitably leads to strong degeneracies in the final mock catalogs, severely limiting their usefulness in understanding AGN evolution and in survey planning and testing.

Keywords: AGN host galaxies, Large-scale structure of the universe, Active galaxies, Active galactic nuclei, X-ray active galactic nuclei
Interrelation of the Environment of Lyα Emitters and Massive Galaxies at 2 &lt; z &lt; 4.5. We present a comparison of the spatial distributions of Lyα emitters (LAEs) and massive star-forming and quiescent galaxies (SFGs and QGs) at 2 &lt; z &lt; 4.5. We use the photometric redshift catalog to select SFGs and QGs and an LAE catalog from intermediate/narrow bands obtained from the Subaru Telescope and Isaac Newton Telescope in the Cosmic Evolution Survey (COSMOS). We derive the auto-/cross-correlation signals of SFGs, QGs, and LAEs and the galaxy overdensity distributions at the position of them. Whereas the cross-correlation signals of SFGs and QGs are explained solely by their halo mass differences, those of SFGs and LAEs are significantly lower than those expected from their autocorrelation signals, suggesting that some additional physical processes are segregating these two populations. Such segregation of SFGs and LAEs becomes stronger for rest-frame ultraviolet faint LAEs (MUV &gt; -20). From the overdensity distributions, LAEs are located in less dense regions than SFGs and QGs, whereas SFGs and QGs tend to be in the same overdensity distributions. The different spatial distributions of LAEs compared to those of massive galaxies may be attributed to assembly bias or large amounts of neutral hydrogen gas associated with massive halos. These results reinforce the importance of exploring multiple galaxy populations in quantifying the intrinsic galaxy environment of the high-z universe.

Keywords: High-redshift galaxies, Galaxy evolution, Galaxy environments
In the Trenches of the Solar-stellar Connection. IV. Solar Full-disk Scans of C II, Si IV, and Mg II by the Interface Region Imaging Spectrograph. About once a month, the Interface Region Imaging Spectrograph conducts day-long raster scans of the full Sun in three ultraviolet spectral channels. These full-disk mosaics are valuable in the solar context, but provide a unique connection to the distant, unresolved stars. Here, 10 deep-exposure scans (4-8 s per slit step), collected during the peak and decline of sunspot Cycle 24, were analyzed. Spatial spectra (2″ pixels) of resonance lines of C II (T ~ 104 K), Si IV (8 × 104 K), and Mg II (8 × 103 K) were fitted with a pseudo-Gaussian model to track the emission strengths, widths, and shifts in the various surface features that comprise the quiet Sun and active regions. The full-disk mosaic spectra compare well to tracings of solar-twin α Centauri A (HD 128620; G2 V). The contrast between disk-average spectra from cycles MIN and MAX is relatively modest (~50% in Si IV), but, remarkably, the brightest solar pixels in active regions, at 2″ resolution, exceed the global-average intensities of the most active Sun-like stars, suggesting a deeper solar-stellar connection. Si IV shows a conspicuous bright ring at the limb, whereas optically thicker C II and Mg II are suppressed (more so for the latter). The Si IV emission favors the bright knots of the large-scale supergranulation network, while the cooler Mg II emission is more ubiquitous and C II intermediate. The non-Gaussian profile of full-disk C IV, similar in formation temperature to Si IV, was previously interpreted as a combination of narrow and broad dynamical components, but the prevalence of the characteristic line shape in the finest resolution spatial pixels of Si IV here provides support for alternative formation scenarios, for example, invoking κ-distributions.

Keywords: Solar cycle, Solar ultraviolet emission, Quiet sun, Active sun, Solar physics
Extreme-ultraviolet Late Phase in Homologous Solar Flares from a Complex Active Region. Recent observations in extreme-ultraviolet (EUV) wavelengths reveal a new late phase in some solar flares, which is seen as a second peak in warm coronal emissions (~3 MK) several tens of minutes to a few hours after the soft X-ray peak. The origin of the EUV late phase (ELP) is explained by either a long-lasting cooling process in the long ELP loops or a delayed energy ejection into the ELP loops well after the main flare heating. Using the observations with the Solar Dynamics Observatory, we investigate the production of the ELP in six homologous flares (F1-F6) originating from a complex active region (AR), NOAA Active Region 11283, with an emphasis on the emission characteristics of the flares. It is found that the main production mechanism of the ELP changes from additional heating in flare F1 to long-lasting cooling in flares F3-F6, with both mechanisms playing a role in flare F2. The transition is evidenced by an abrupt decrease of the time lag of the ELP peak, and the long-lasting cooling process in the majority of the flares is validated by a positive correlation between the flare ribbon fluence and the ELP peak intensity. We attribute the change in ELP production mechanism to an enhancement of the envelope magnetic field above the AR, which facilitates a more prompt and energetic heating of the ELP loops. In addition, the last and the only confined flare F6 exhibits an extremely large ELP. The different emission pattern revealed in this flare may reflect a different energy partitioning inside the ELP loops, which is due to a different magnetic reconnection process.

Keywords: Solar active regions, Solar flares, Solar extreme ultraviolet emission
Star Formation Histories of Massive Red Spiral Galaxies in the Local Universe. We investigate the star formation histories (SFHs) of massive red spiral galaxies with stellar mass M* &gt; 1010.5 M⊙, and make comparisons with blue spirals and red ellipticals of similar masses. We make use of the integral field spectroscopy from the Sloan Digital Sky Survey IV/DR15 MaNGA sample, and estimate spatially resolved SFHs and stellar population properties of each galaxy by applying a Bayesian spectral fitting code to the MaNGA spectra. We find that both red spirals and red ellipticals have experienced only one major star formation episode at early times, and the result is independent of the adopted SFH model. On average, more than half of their stellar masses were formed &gt;10 Gyr ago, and more than 90% were formed &gt;6 Gyr ago. The two types of galaxies show similarly flat profiles in a variety of stellar population parameters: old stellar ages indicated by D4000 (the spectral break at around 4000 Å), high stellar metallicities, large Mgb/Fe ratios indicating fast formation, and little stellar dust attenuation. In contrast, although blue spirals also formed their central regions &gt;10 Gyr ago, both their central regions and outer disks continuously form stars over a long timescale. Our results imply that massive red spirals are likely to share some common processes of formation (and possibly quenching) with massive red ellipticals in the sense that both types were formed at z &gt; 2 through a fast formation process. Possible mechanisms for the formation and quenching of massive red spirals are discussed.

Keywords: Galaxy stellar content, Galaxy formation, Galaxy evolution, Spiral galaxies
Effects of Spatial Discretization in Lyα Line Radiation Transfer Simulations. We describe the addition of Lyα resonant line transfer to our dust continuum radiation transfer code SKIRT, verifying our implementation with published results for spherical problems and using some self-designed three-dimensional setups. We specifically test spatial discretization through various grid types, including hierarchical octree grids and unstructured Voronoi tessellations. We then use a radiation transfer postprocessing model for one of the spiral galaxies produced by the Auriga cosmological zoom simulations to investigate the effect of spatial discretization on the synthetic observations. We find that the calculated Lyα line profiles exhibit an extraordinarily strong dependence on the type and resolution of the spatial grid, rendering the results untrustworthy at best. We attribute this effect to the large gradients in the hydrogen density distribution over small distances, which remain significantly underresolved in the input model. We therefore argue that further research is needed to determine the required spatial resolution of a hydrodynamical simulation snapshot to enable meaningful Lyα line transfer postprocessing.

Keywords: Publicly available software, Hydrodynamical simulations, Interstellar line emission, Computational methods, Interstellar scattering, Lyman-alpha galaxies, Radiative transfer simulations