Sazuna/UAT_keywords huggingface dataset:
Implications for Primordial Black Holes from Cosmological Constraints on Scalar-induced Gravitational Waves. Sufficiently large scalar perturbations in the early universe can create overdense regions that collapse into primordial black holes (PBHs). This process is accompanied by the emission of scalar-induced gravitational waves that behave like an extra radiation component, thus contributing to the relativistic degrees of freedom (N eff). We show that the cosmological constraints on N eff can be used to pose stringent limits on PBHs created from this particular scenario as well as the relevant small-scale curvature perturbation ( ${{ \mathcal P }}_{{ \mathcal R }}(k)$ ). We show that the combination of cosmic microwave background (CMB), baryon acoustic oscillation, and Big Bang nucleosynthesis data sets can exclude supermassive PBHs with peak mass M • ∈ [5 × 105, 5 × 1010] M ⊙ as the major component of dark matter, while the detailed constraints depend on the shape of the PBHs' mass distribution. A future CMB mission such as CMB-S4 can greatly broaden this constraint window to M • ∈ [8 × 10-5, 5 × 1010] M ⊙, covering substellar masses. These limits on PBHs correspond to a tightened constraint on ${{ \mathcal P }}_{{ \mathcal R }}$ on scales of k ∈ [10, 1022] Mpc-1, much smaller than those probed by direct CMB and large-scale structure power spectra.

Keywords: Cosmological perturbation theory
Dark Matter in Fractional Gravity. I. Astrophysical Tests on Galactic Scales. We explore the possibility that the dark matter (DM) component in galaxies may originate fractional gravity. In such a framework, the standard law of inertia continues to hold, but the gravitational potential associated with a given DM density distribution is determined by a modified Poisson equation including fractional derivatives (i.e., derivatives of noninteger type) that are meant to describe nonlocal effects. We analytically derive the expression of the potential that in fractional gravity corresponds to various spherically symmetric density profiles, including the Navarro-Frenk-White (NFW) distribution that is usually exploited to describe virialized halos of collisionless DM as extracted from N-body cosmological simulations. We show that in fractional gravity, the dynamics of a test particle moving in a cuspy NFW density distribution is substantially altered with respect to the Newtonian case, mirroring what in Newtonian gravity would instead be sourced by a density profile with an inner core. We test the fractional gravity framework on galactic scales, showing that (i) it can provide accurate fits to the stacked rotation curves of spiral galaxies with different properties, including dwarfs; (ii) it can reproduce to reasonable accuracy the observed shape and scatter of the radial acceleration relation over an extended range of galaxy accelerations; and (iii) it can properly account for the universal surface density and the core radius versus disk scale length scaling relations. Finally, we discuss the possible origin of the fractional gravity behavior as a fundamental or emerging property of the elusive DM component.

Keywords: Cosmology, Non-standard theories of gravity, Dark matter
Heating of Quiescent Coronal Loops Caused by Nearby Eruptions Observed with the Solar Dynamics Observatory and the Solar Upper Transition Region Imager. How structures, e.g., magnetic loops, in the upper atmosphere, i.e., the transition region and corona, are heated and sustained is one of the major unresolved issues in solar and stellar physics. Various theoretical and observational studies on the heating of coronal loops have been undertaken. The heating of quiescent loops caused by eruptions, however, is rarely observed. In this study, employing data from the Solar Dynamics Observatory (SDO) and Solar Upper Transition Region Imager (SUTRI), we report the heating of quiescent loops associated with nearby eruptions. In active regions (ARs) 13092 and 13093, a long filament and a short filament, and their overlying loops, were observed on 2022 September 4. In AR 13093, a warm channel erupted toward the northeast, whose material moved along its axis toward the northwest under the long filament, turned to the west above the long filament, and divided into two branches falling to the solar surface. Subsequently, the short filament erupted toward the southeast. Associated with these two eruptions, the quiescent loops overlying the long filament appeared in SDO/Atmospheric Imaging Assembly (AIA) high-temperature images, indicating the heating of loops. During the heating, the signature of magnetic reconnection between loops is identified, including the inflowing motions of loops, and the formation of X-type structures and newly reconnected loops. The heated loops then cooled down. They appeared sequentially in AIA and SUTRI lower-temperature images. All the results suggest that the quiescent loops are heated by reconnection between loops caused by the nearby warm channel and filament eruptions.

Keywords: Solar magnetic reconnection, Solar coronal heating, Plasma astrophysics, Solar filaments, Solar magnetic fields, Solar radiation
Strong Dark Matter Self-interactions Diversify Halo Populations within and surrounding the Milky Way. We perform a high-resolution cosmological zoom-in simulation of a Milky Way (MW)-like system, which includes a realistic Large Magellanic Cloud analog, using a large differential elastic dark matter self-interaction cross section that reaches ≈100 cm2 g-1 at relative velocities of ≈10 km s-1, motivated by the diverse and orbitally dependent central densities of dwarf galaxies within and surrounding the MW. We explore the effects of dark matter self-interactions on satellite, splashback, and isolated halos through their abundance, central densities, maximum circular velocities, orbital parameters, and correlations between these variables. We use an effective constant cross section model to analytically predict the stages of our simulated halos' gravothermal evolution, demonstrating that deviations from the collisionless ${R}_{\max }$ - ${V}_{\max }$ relation can be used to select deeply core-collapsed halos, where ${V}_{\max }$ is a halo's maximum circular velocity, and ${R}_{\max }$ is the radius at which it occurs. We predict that a sizable fraction (≈20%) of subhalos with masses down to ≈108 M ⊙ is deeply core collapsed in our SIDM model. Core-collapsed systems form ≈10% of the isolated halo population down to the same mass; these isolated, core-collapsed halos would host faint dwarf field galaxies with extremely steep central density profiles. Finally, most halos with masses above ≈109 M ⊙ are core-forming in our simulation. Our study thus demonstrates how self-interactions diversify halo populations in an environmentally dependent fashion within and surrounding MW-mass hosts, providing a compelling avenue to address the diverse dark matter distributions of observed dwarf galaxies.

Keywords: Galaxy dark matter halos, Computational methods, Galaxy abundances, N-body simulations, Dark matter
On the Dynamical Heating of Dwarf Galaxies in a Fuzzy Dark Matter Halo. Fuzzy dark matter (FDM), consisting of ultralight bosons, is an intriguing alternative to cold dark matter. Numerical simulations solving the Schrödinger-Poisson (SP) equation, which governs FDM dynamics, show that FDM halos consist of a central solitonic core (representing the ground state of the SP equation), surrounded by a large envelope of excited states. Wave interference gives rise to density fluctuations of order unity throughout the envelope and causes the soliton to undergo density oscillations and execute a confined random walk in the central region of the halo. The resulting gravitational potential perturbations are an efficient source of dynamical heating. Using high-resolution numerical simulations of a 6.6 × 109 M ⊙ FDM halo with boson mass m b = 8 × 10-23 eV, we investigate the impact of this dynamical heating on the structure and kinematics of spheroidal dwarf galaxies of a fixed mass but different initial sizes and ellipticities. The galaxies are set up in equilibrium in the time-and-azimuthally averaged halo potential and evolved for 10 Gyr in the live FDM halo. We find that they continuously increase their sizes and central velocity dispersions. In addition, their kinematic structures become strongly radially anisotropic, especially in the outskirts. Dynamical heating also causes initially ellipsoidal galaxies to become more spherical over time from the inside out and gives rise to distorted, nonconcentric isodensity contours. These telltale characteristics of dynamical heating of dwarf galaxies in FDM halos can potentially be used to constrain the boson mass.

Keywords: Gravitational interaction, Galaxy dark matter halos, Galaxy dynamics
The Nature of LoBAL QSOs. II. HST/WFC3 Observations Reveal Host Galaxies Dominated by Mergers. Low-ionization broad absorption line QSOs (LoBALs) are suspected to be merging systems in which extreme, active galactic nucleus-driven outflows have been triggered. Whether or not LoBALs are uniquely associated with mergers, however, has yet to be established. To characterize the morphologies of LoBALs, we present the first high-resolution morphological analysis of a volume-limited sample of 22 Sloan Digital Sky Survey (SDSS)-selected LoBALs at 0.5 &lt; z &lt; 0.6 from Hubble Space Telescope Wide Field Camera 3 observations. Host galaxies are resolved in 86% of the systems in F125W, which is sensitive to old stellar populations, while only 18% are detected in F475W, which traces young, unobscured stellar populations. Signs of recent or ongoing tidal interaction are present in 45%-64% of the hosts, including double nuclei, tidal tails, bridges, plumes, shells, and extended debris. Ongoing interaction with a companion is apparent in 27%-41% of the LoBALs, with as much as 1/3 of the sample representing late-stage mergers at projected nuclear separations &lt;10 kpc. Detailed surface brightness modeling indicates that 41% of the hosts are bulge dominated while only 18% are disks. We discuss trends in various properties as a function of merger stage and parametric morphology. Notably, mergers are associated with slower, dustier winds than those seen in undisturbed/unresolved hosts. Our results favor an evolutionary scenario in which quasar-level accretion during various merger stages is associated with the observed outflows in low-z LoBALs. We discuss differences between LoBALs and FeLoBALs and show that selection via the traditional balnicity index would have excluded all but one of the mergers.

Keywords: Broad-absorption line quasar, Quasars, Active galaxies, Galaxy evolution, Interacting galaxies
Reflection and Timing Study of the Transient Black Hole X-Ray Binary MAXI J1803-298 with NuSTAR. The transient black hole X-ray binary MAXI J1803-298 was discovered on 2021 May 1, as it went into outburst from a quiescent state. As the source rose in flux it showed periodic absorption dips and fit the timing and spectral characteristics of a hard-state accreting black hole. We report on the results of a Target-of-Opportunity observation with NuSTAR obtained near the peak outburst flux beginning on 2021 May 13, after the source had transitioned into an intermediate state. MAXI J1803-298 is variable across the observation, which we investigate by extracting spectral and timing products separately for different levels of flux throughout the observation. Our timing analysis reveals two distinct potential quasiperiodic oscillations (QPOs) which are not harmonically related at 5.4 ± 0.2 Hz and 9.4 ± 0.3 Hz, present only during periods of lower flux. With clear relativistic reflection signatures detected in the source spectrum, we applied several different reflection models to the spectra of MAXI J1803-298. Here we report our results, utilizing high-density reflection models to constrain the disk geometry, and assess changes in the spectrum dependent on the source flux. With a standard broken power-law emissivity, we find a near-maximal spin for the black hole, and we are able to constrain the inclination of the accretion disk at 75° ± 2°, which is expected for a source that has shown periodic absorption dips. We also significantly detect a narrow absorption feature at 6.91 ± 0.06 keV with an equivalent width between 4 and 9 eV, which we interpret as the signature of a disk wind.

Keywords: Accretion, X-ray binary stars, Stellar mass black holes, X-ray transient sources, X-ray sources, Low-mass x-ray binary stars
First-principles-integrated Study of Blazar Synchrotron Radiation and Polarization Signatures from Magnetic Turbulence. Blazar emission is dominated by nonthermal radiation processes that are highly variable across the entire electromagnetic spectrum. Turbulence, which can be a major source of nonthermal particle acceleration, can widely exist in the blazar emission region. The Turbulent Extreme Multi-Zone (TEMZ) model has been used to describe turbulent radiation signatures. Recent particle-in-cell (PIC) simulations have also revealed the stochastic nature of the turbulent emission region and particle acceleration therein. However, radiation signatures have not been systematically studied via first-principles-integrated simulations. In this paper, we perform combined PIC and polarized radiative transfer simulations to study synchrotron emission from magnetic turbulence in the blazar emission region. We find that the multiwavelength flux and polarization are generally characterized by stochastic patterns. Specifically, the variability timescale and average polarization degree (PD) are governed by the correlation length of the turbulence. Interestingly, magnetic turbulence can result in polarization angle swings with arbitrary amplitudes and duration, in either direction, that are not associated with changes in flux or PD. Surprisingly, these swings, which are stochastic in nature, can appear either bumpy or smooth, although large-amplitude swings (&gt;180°) are very rare, as expected. Our radiation and polarization signatures from first-principles-integrated simulations are consistent with the TEMZ model, except that in the latter, there is a weak correlation, with zero lag, between flux and degree of polarization.

Keywords: Blazars, Non-thermal radiation sources, Spectropolarimetry, Plasma astrophysics
HST Imaging of Star-forming Clumps in Six GASP Ram-pressure-stripped Galaxies. Exploiting broad- and narrowband images of the Hubble Space Telescope from the near-UV to I-band rest frame, we study the star-forming clumps of six galaxies of the GASP sample undergoing strong ram pressure stripping. Clumps are detected in Hα and near-UV, tracing star formation on different timescales. We consider clumps located in galaxy disks and stripped tails and formed in stripped gas but still close to the disk, called extraplanar. We detect 2406 Hα-selected clumps (1708 in disks, 375 in extraplanar regions, and 323 in tails) and 3745 UV-selected clumps (2021 disk, 825 extraplanar, and 899 tail clumps). Only ~15% of star-forming clumps are spatially resolved, meaning that most are smaller than ~140 pc. We study the luminosity and size distribution functions (LDFs and SDFs, respectively) and the luminosity-size relation. The average LDF slope is 1.79 ± 0.09, while the average SDF slope is 3.1 ± 0.5. The results suggest that the star formation is turbulence-driven and scale-free, as in main-sequence galaxies. All of the clumps, whether they are in the disks or tails, have an enhanced Hα luminosity at a given size, compared to the clumps in main-sequence galaxies. Indeed, their Hα luminosity is closer to that of clumps in starburst galaxies, indicating that ram pressure is able to enhance the luminosity. No striking differences are found among disk and tail clumps, suggesting that the different environments in which they are embedded play a minor role in influencing the star formation.

Keywords: Galaxy clusters, Star forming regions, Galaxy structure, Galaxy tails, Star formation, Galaxy evolution
Clustercentric Distance or Local Density? It Depends on Galaxy Morphology. Determining which between projected local density and distance from the cluster center plays a major role in regulating morphological fractions in clusters is a longstanding debate. Reaching a definitive answer will shed light on the main physical mechanisms at play in the most extreme environments. Here we make use of the data from the OmegaWINGS survey, currently the largest survey of clusters in the local universe extending beyond 2 virial radii from the cluster cores, to extend the previous analysis outside the virial radius. Local density and clustercentric distance seems to play different roles for galaxies of different morphology: the fraction of elliptical galaxies mainly depends on local density, suggesting that their formation was linked to the primordial densities, which now correspond to the cluster cores. Only the fraction of low-mass ellipticals shows an anticorrelation with clustercentric distance, suggesting a different origin for these objects. Excluding elliptical galaxies, the relative fraction of S0s and spirals instead depends on local density only far from the cluster cores, while within the virial radius their proportion is regulated by distance, suggesting that cluster-specific processes halt the star formation and transform Sp galaxies into S0s. This interpretation is supported by literature results on the kinematical analysis of early- and late-type galaxies, according to which fast and slow rotators have distinct dependencies on halo mass and local density.

Keywords: Lenticular galaxies, Late-type galaxies, Spiral galaxies, Early-type galaxies, Galaxy evolution, Elliptical galaxies, Galaxies
Infrared Ejecta and Cold Dust in the Young Supernova Remnant N132D. We present Spitzer, Wide-field Infrared Survey Explorer (WISE), and Herschel observations of the young supernova remnant (SNR) N132D in the Large Magellanic Cloud, including 3-40 μm Spitzer Infrared Spectrograph (IRS) mapping, 12 μm WISE and 70, 100, 160, 250, 350, and 500 μm Herschel images. The high-velocity lines of [Ne II] at 12.8 μm, [Ne III] at 15.5 μm, and [O IV] 26 μm reveal infrared ejecta concentrated in a central ring and coincide with the optical and X-ray ejecta. Herschel images reveal far-IR emission coinciding with the central ejecta, which suggests that the IR emission is freshly formed, cold dust in the SN ejecta. The infrared spectra are remarkably similar to those of another young SNR of 1E0102 with Ne and O lines. Shock modeling of the Ne ejecta emission suggests a gas temperature of 300-600 K and densities in the range 1000-2 × 104 cm-3 in the postshock photoionized region. The IR continuum from the ejecta shows an 18 μm peak dust feature. We performed spectral fitting to the IRS dust continuum and Herschel photometry. The dust mass associated with the central ejecta is 1.25 ± 0.65 M ⊙, while the 18 μm dust feature requires forsterite grains. The dust mass of the central ejecta region in N132D is higher than those of other young SNRs, which is likely associated with its higher progenitor mass. We discuss the dust productivity in the ejecta of N132D and infer its plausible implications for dust in the early universe.

Keywords: Early universe, Origin of the universe, Core-collapse supernovae, Type Ib supernovae, Large Magellanic Cloud, Far infrared astronomy, Supernova remnants, Interstellar emissions, Dust continuum emission
The Type II-P Supernova 2019mhm and Constraints on its Progenitor System. We present pre- and postexplosion observations of the Type II-P supernova (SN II-P) 2019mhm located in NGC 6753. Based on optical spectroscopy and photometry, we show that SN 2019mhm exhibits broad lines of hydrogen with a velocity of -8500 ± 200 km s-1 and a 111 ± 2 day extended plateau in its luminosity, typical of the Type II-P subclass. We also fit its late-time bolometric light curve and infer that it initially produced a 56Ni mass of 1.3 × 10-2 ± 5.5 × 10-4 M ⊙. Using imaging from the Wide Field Planetary Camera 2 on the Hubble Space Telescope obtained 19 yr before explosion, we aligned to a postexplosion Wide Field Camera 3 image and demonstrate that there is no detected counterpart to the SN to a limit of &gt;24.53 mag in F814W, corresponding to an absolute magnitude limit of M F814W &lt; -7.7 mag. Comparing to massive-star evolutionary tracks, we determine that the progenitor star had a maximum zero-age main-sequence mass &lt;17.5 M ⊙, consistent with other SN II-P progenitor stars. SN 2019mhm can be added to the growing population of SNe II-P with both direct constraints on the brightness of their progenitor stars and well-observed SN properties.

Keywords: Core-collapse supernovae
Modeling the Radiation Environment of Energetic Particles at Mars Orbit and a First Validation against TGO Measurements. Sending astronauts to Mars will be a milestone of future deep space exploration activities. However, energetic particle radiation in deep space and in the Mars environment is a major risk to the health of future human explorers. The nominal Martian surface radiation field contains primary Galactic Cosmic Ray (GCR) particles and secondary particles generated in the Martian atmosphere and the regolith. Some of these secondary particles may propagate upward and even be detected at the orbit of Mars contributing to the orbit radiation. Studying the Mars orbit radiation environment is critical for planning future Mars orbital missions. Therefore, we calculate the Martian orbit radiation dose rate considering the primary GCR spectra provided by the Badhwar-O'Neill 2014 model and the secondary particles modeled by the state-of-the-art Atmospheric Radiation Interaction Simulator. Specifically, we calculate the integral dose rate of each particle type and its dependence on orbit height, surface pressure, and solar modulation intensity. Our analysis shows that modulation intensity is the most dominating factor and that different surface pressures make less than a 1% impact. We also derive the sensitive energy range of detected particles contributing to the dose rate and further validate our prediction against the measured data by Liulin-MO on TGO at a circular orbit around Mars. This may conduce to predicting the radiation risks in Mars orbit and providing constructive reference parameters for the crewed space industry.

Keywords: Mars, Space research, High-energy cosmic radiation
Constraint on the Accretion of NGC 6946 X-1 Using Broadband X-Ray Data. We analyze broadband X-ray data of NGC 6946 X-1 and probe plausible accretion scenarios in this ULX. NGC 6946 X-1 is a persistent soft source with broadband continuum spectra described by two thermal disk components. The cool accretion disk temperature T cool ~ 0.2 keV and the presence of a ~0.9 keV emission/absorption broad feature suggest evidence of an optically thick wind due to supercritical accretion. The hot geometrically modified accretion disk has an inner temperature of T hot ~ 2 keV with a radially dependent profile T(r) ∝ r -0.5, expected in a slim-disk scenario. Further, the measurement based on a realistic inclination angle of the disk indicates that the mass of the host compact object is comparable to a ~6-10 M ☉ nonrotating black hole or the system hosts a moderately magnetized neutron star with a B ≲ 2 × 1011 G magnetic field. Overall, the detected spectral curvature, high luminosity, flux contribution from two thermal disk components, and estimated accretion rate support the super-Eddington accretion scenario.

Keywords: Accretion, Ultraluminous x-ray sources, X-ray sources, X-ray binary stars