Sazuna/UAT_keywords huggingface dataset:
The Relation between Globular Cluster Systems and Supermassive Black Holes in Spiral Galaxies. III. The Link to the M <SUB>•</SUB>-M <SUB>*</SUB> Correlation. We continue to explore the relationship between the total number of globular clusters (GCs), N GC, and the central black hole mass, M •, in spiral galaxies. We present here results for the Sab galaxies NGC 3368, NGC 4736 (M94), and NGC 4826 (M64), and the Sm galaxy NGC 4395. The GC candidate selection is based on the (u* - $i^{\prime} $ ) versus ( $i^{\prime} $ - K  s ) color-color diagram, and $i^{\prime} $ -band shape parameters. We determine the M • versus N GC correlation for these spirals, plus NGC 4258, NGC 253, M104, M81, M31, and the Milky Way. We also redetermine the correlation for the elliptical sample in Harris et al., with updated galaxy types from Sahu et al. Additionally, we derive the total stellar galaxy mass, M *, from its two-slope correlation with N GC, and fit M • versus M * for both spirals and ellipticals. We obtain log M • ∝ (1.01 ± 0.13) log N GC for ellipticals, and log M • ∝ (1.64 ± 0.24) log N GC for late-type galaxies (LTGs). The linear M • versus N GC correlation in ellipticals could be due to statistical convergence through mergers, unlike the much steeper correlation for LTGs. However, in the M • versus total stellar mass (M *) parameter space, with M * derived from its correlation with N GC, M • ∝ (1.48 ± 0.18) log M * for ellipticals, and M • ∝ (1.21 ± 0.16) log M * for LTGs. The observed agreement between ellipticals and LTGs in this parameter space may imply that black holes and galaxies coevolve through calm accretion, active galactic nuclei feedback, and other secular processes.

Keywords: Globular star clusters, Galaxy formation, Black holes, Spiral galaxies, Galaxy evolution, Classical black holes, Star clusters
The Dust Cycle on Mars at Different Orbital Distances from the Sun: An Investigation of the Impact of Radiatively Active Dust on Land Planet Climate. The dust cycle is the dominant driver of meteorology and climate on present-day Mars. Despite this, few studies have investigated the impact of dust interacting with incoming stellar radiation on the climate, habitability, and potential spectral signature of Mars-like exo-land planets. Dust availability is positively correlated with increasing soil aridity and therefore dust has significant potential to modify dynamics on dry land planets. In this work, we use an advanced Mars general circulation model to study the coupling between radiatively active dust and land planet climate at different stellar heating rates or planetary orbits. We find that radiatively active dust can significantly modify land planet climate. At Earth orbit, dust with optical properties similar to present-day Mars warms the planetary surface above 273 K and augments both the zonal mean circulation and the thermal tide, and in particular the semidiurnal component. As dust accumulates, peak heating rises off the planetary surface and the most active regions of dust lifting shift from the summer to winter hemisphere. Simulated spectra are nearly featureless across all wavelengths. We find that in order to accurately assess the climate and habitability of land planets it is critical to carefully consider that potential atmospheric dust budget and its radiative impact.

Keywords: Extrasolar rocky planets, Exoplanets, Planetary atmospheres, Planetary climates, Planetary science, Habitable planets, Atmospheric variability
Distinguishing Dark Matter, Modified Gravity, and Modified Inertia with the Inner and Outer Parts of Galactic Rotation Curves. The missing gravity in galaxies requires dark matter, or alternatively a modification of gravity or inertia. These theoretical possibilities of fundamental importance may be distinguished by the statistical relation between the observed centripetal acceleration of particles in orbital motion and the expected Newtonian acceleration from the observed distribution of baryons in galaxies. Here predictions of cold dark matter halos, modified gravity, and modified inertia are compared and tested by a statistical sample of galaxy rotation curves from the Spitzer Photometry and Accurate Rotation Curves database. Modified gravity under an estimated mean external field correctly predicts the observed statistical relation of accelerations from both the inner and outer parts of rotation curves. Taken at face value there is a $6.9{\sigma }$ difference between the inner and outer parts on an acceleration plane which would be inconsistent with current proposals of modified inertia. Removing galaxies with possible systematic concerns such as central bulges or special inclinations does not change this trend. Cold dark matter halos predict a systematically deviating relation from the observed one. All aspects of rotation curves appear to be most naturally explained by modified gravity.

Keywords: Modified Newtonian dynamics, Dark matter, Disk galaxies
Influence of Neutrino-Nuclear Reactions on the Abundance of <SUP>74</SUP>Se. The p-nuclei are supposed to be produced in different astrophysical processes, such as rapid-proton capture, photonuclear reaction, and neutrino-induced reaction. To date, their abundance cannot be reasonably explained. In the present work, the cross sections of the 74Ge (ν  e , e -) 74As reaction are calculated with the theoretical and experimental B(GT) values, respectively. The abundance ratios between 74Se and 74Ge produced from the neutrino process (ν-process) are estimated based on the simple hypothesis for core-collapse supernova explosions. The results show that the upper limit of the 74Se and 74Ge abundance ratio resulting from the ν-process is about 36% of the value in the solar system.

Keywords: Supernova neutrinos, P-process, Explosive nucleosynthesis, Core-collapse supernovae
Explaining the Moderate UV/X-Ray Correlation in AGN. The UV/optical and X-ray variability of active galactic nuclei (AGN) have long been expected to be well correlated as a result of the X-ray illumination of the accretion disk. Recent monitoring campaigns of nearby AGN, however, found that their X-ray and UV/optical emission are only moderately correlated, challenging the aforementioned paradigm. In this work, we aim to demonstrate that due to the definition of the cross-correlation function, a low UV/X-ray correlation is well expected in the case of an X-ray illuminated accretion disk, when the dynamic variability of the X-ray source is taken into account. In particular, we examine how the variability of the geometric or physical configuration of the X-ray source affects the expected correlation. Variations of the geometric configuration are found to produce a range of UV/X-ray cross correlations, which match well the observed values, while they result in a high correlation between the UV and optical variability, reconciling the observed results with theoretical predictions. We conclude that the detection of a low UV/X-ray correlation does not contradict the assumption of the UV/optical variability being driven by the X-ray illumination of the disk, and we discuss the implications of our results for correlation studies.

Keywords: Seyfert galaxies, Active galactic nuclei
On the Local Structure of Stochastic Parker Spirals in the Solar Wind. We present a Langevin model describing the local structure of the interplanetary magnetic field lines. It is established on the basis of the analysis of the Lagrangian properties of strong Alfvénic turbulence, which provides a new perspective on the critical balance condition. The model is consistent with the ${k}_{\parallel }^{-2}$ spectrum of magnetic fluctuations derived from in situ measurements. We show that the magnetic field line diffusivity at the spacecraft position can be inferred from the wavelet analysis of one-point measurements of the fluctuating magnetic fields in the solar wind independently of the three-dimensional nature of the anisotropy.

Keywords: Interplanetary turbulence, Magnetohydrodynamics
Recurrent Narrow Quasiperiodic Fast-propagating Wave Trains Excited by the Intermittent Energy Release in the Accompanying Solar Flare. About the driven mechanisms of the quasiperiodic fast-propagating (QFP) wave trains, there exist two dominant competing physical explanations: they are associated with the flaring energy release or attributed to the waveguide dispersion. Employing Solar Dynamics Observatory/Atmospheric Imaging Assembly 171 Å images, we investigated a series of QFP wave trains composed of multiple wave fronts propagating along a loop system during the accompanying flare on 2011 November 11. The wave trains showed a high correlation in start times with the energy release of the accompanying flare. Measurements show that the wave trains' phase speed is almost consistent with its group speed with a value of about 1000 km s-1, indicating that the wave trains should not be considered dispersed waves. The period of the wave trains was the same as that of the oscillatory signal in X-ray emissions released by the flare. Thus we propose that the QFP wave trains were most likely triggered by the flare rather than by dispersion. We investigated the seismological application with the QFP waves and then obtained that the magnetic field strength of the waveguide was about 10 G. Meanwhile, we also estimated that the energy flux of the wave trains was about 1.2 × 105 erg cm-2 s-1.

Keywords: Alfven waves, Solar coronal waves, Solar corona
Does the Streaming Instability Exist within the Terminal Velocity Approximation?. Terminal velocity approximation is appropriate to study the dynamics of a gas-dust mixture with solids tightly coupled to the gas. This work reconsiders its compatibility with physical processes giving rise to the resonant streaming instability in the low-dust-density limit. It is shown that the linearized equations that have been commonly used to study the streaming instability within the terminal velocity approximation actually exceed the accuracy of this approximation. For that reason, the corresponding dispersion equation recovers the long-wavelength branch of the resonant streaming instability caused by the stationary azimuthal drift of the dust. However, the latter must remain beyond the terminal velocity approximation by its physical definition. The refined equations for gas-dust dynamics in the terminal velocity approximation does not lead to the resonant streaming instability. The work additionally elucidates the physical processes responsible for the instability.

Keywords: Protoplanetary disks
An Improved Magnetohydrodynamic Simulation of the 2006 December 13 Coronal Mass Ejection of NOAA Active Region 10930. We present a magnetohydrodynamic simulation of the coronal mass ejection on 2006 December 13 in the emerging δ-sunspot NOAA Active Region 10930, improving upon a previous simulation by Fan as follows. (1) Incorporate an ambient solar wind instead of using a static potential magnetic field extrapolation as the initial state. (2) In addition to imposing the emergence of a twisted flux rope, also impose at the lower boundary a random electric field that represents the effect of turbulent convection, which drives field-line braiding and produces resistive and viscous heating in the corona. With the inclusion of this heating, which depends on the magnetic field topology, we are able to model the synthetic soft X-ray images that would be observed by the X-Ray Telescope (XRT) of the Hinode satellite, produced by the simulated coronal magnetic field. We find that the simulated preeruption magnetic field with the buildup of a twisted magnetic flux rope produces synthetic soft X-ray emission that shows qualitatively similar morphology as that observed by the Hinode/XRT for both the ambient coronal loops of the active region and the central inverse S-shaped "sigmoid" that sharpens just before the onset of the eruption. The synthetic postflare loop brightening also shows similar morphology to that seen in the Hinode/XRT image during the impulsive phase of the eruption. It is found that the kinematics of the erupting flux rope is significantly affected by the open magnetic fields and fast solar wind streams adjacent to the active region.

Keywords: Solar magnetic fields, Magnetohydrodynamics, Solar coronal mass ejections, Magnetohydrodynamical simulations
Searching for Converging Flows of Atomic Gas onto a Molecular Cloud. We present new observations of [C II] 2 P 3/2 → 2 P 1/2 fine structure line emission from an isolated molecular cloud using the upGREAT instrument on board SOFIA. These data are analyzed together with archival CO J=1-0 and H I 21 cm emission spectra to investigate the role of converging atomic gas flows in the formation of molecular clouds. Bright [C II] emission is detected throughout the mapped area that likely originates from photodissociation regions excited by UV radiation fields produced by newborn stars within the cloud. Upon spatial averaging of the [C II] spectra, we identify weak [C II] emission within velocity intervals where the H I 21 cm line is brightest; these are blueshifted relative to velocities of the CO and bright [C II] emission by 4 km s-1. The brightness temperatures, velocity dispersions, and alignment with H I 21 cm velocities connect this [C II] emission component to the cold, neutral atomic gas of the interstellar medium, known as the cold, neutral medium (CNM). We propose that this CNM feature is an accretion flow onto the farside of the existing molecular cloud. The mass infall rate is 3.2 × 10-4 M ⊙ yr-1. There is no direct evidence of a comparable redshifted component in the [C II] or H I 21 cm spectral lines that would indicate the presence of a converging flow.

Keywords: Molecular gas, Interstellar phases, Molecular clouds, Photodissociation regions, Neutral hydrogen clouds, Interstellar clouds, Cold neutral medium
Photometric and Spectroscopic Observations of GRB 210104A: Bright Reverse-shock Emission and Dense Circumburst Environment. Early afterglow observations of gamma-ray bursts (GRBs) are valuable for exploring the properties of their jets and ambient medium. We report our photometric and spectroscopic observations of GRB 210104A and discuss its jet properties with multiwavelength data. Our spectroscopic observation reveals several absorption features and a tentative redshift of 0.46 is identified. A bright optical flare that has a peak brightness of R = 13 mag at 112 ± 7 s was observed in the R band during 67 ~ 165 s post the GRB trigger. The flux of the R-band afterglow decays with a slope of α O = - 0.91 ± 0.03 at t &gt; 650 s. The early X-ray afterglow lightcurve is a smooth bump, and it decays with a slope of α X = -1.18 ± 0.01 at late epoch. Our joint spectral fit to the optical-X-ray afterglows during (1.1-1.3) × 104 s yields a photon index ΓO,X = -1.82 ± 0.04. The derived host galaxy extinction is A  R  = 0.87. Attributing the early optical flare to the reverse-shock (RS) emission and the late optical-X-ray emission to the forward shock emission, the optical and X-ray lightcurves at t &lt; 3 × 104 s can be well fit adopting a Markov Chain Monte Carlo algorithm. Comparing the properties of GRB 210104A with other GRBs that have detection of bright RS emission, we show that its jet is mildly magnetized (R B = 28), with high radiation efficiency (77%), is subenergetic (E k,iso = 4.5 × 1051 erg), and moderately relativistic (Γ0 ~ 35) in a density medium (n 0 ~ 417 cm-3). It follows the tight L  γ,iso-E p,z-Γ0 relation as with typical GRBs.

Keywords: Gamma-ray bursts
Near-infrared Spectroscopy of Ultracompact H II Regions in W51A with NIFS/ALTAIR. W51A is the most active star formation region of the giant H II region W51. It harbors the two massive protoclusters W51e and W51 IRS2, which are very rare in the Galaxy. We aim to identify the newborn massive stars and ultracompact H II regions to derive its distance and age. We performed Integral Field Unit observations with NIFS+ALTAIR of nine targets in the W51A subregion. The distance modulus was obtained using the spectral classification in the K band and a reddening law appropriate to the inner Galactic plane. We derived the distance and the spectral types for five of the targets, ranging from O8 to O9.5, similar to those derived from radio continuum data, except for two sources to which we assigned a somewhat later spectral type. We included another seven objects with precise spectral classification from other works, which allowed us to better constrain the distance estimate. Our spectrophotometric distance d = 4.80 ± 1.27 kpc is in good agreement with those derived from the Galactic rotation model and trigonometric parallaxes, placing the region near the tangent point of the Sagittarius arm. We conclude that the stars studied in this work have an age spread of 1.5-4 Myr, substantially older than thought to date. *Based on observations obtained at the Gemini Observatory (processed using the Gemini IRAF package v1.14), which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), National Research Council (Canada), CONICYT (Chile), Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina), Ministério da Ciência, Tecnologia e Inovação (Brazil), and Korea Astronomy and Space Science Institute (Republic of Korea).

Keywords: Massive stars, Star forming regions, Spectroscopy, Stellar spectral types, Stellar spectral lines, Spectrophotometry, Near infrared astronomy
Turbulent Reacceleration of Streaming Cosmic Rays. Subsonic, compressive turbulence transfers energy to cosmic rays (CRs), a process known as nonresonant reacceleration. It is often invoked to explain the observed ratios of primary to secondary CRs at ~GeV energies, assuming wholly diffusive CR transport. However, such estimates ignore the impact of CR self-confinement and streaming. We study these issues in stirring box magnetohydrodynamic (MHD) simulations using Athena++, with field-aligned diffusive and streaming CR transport. For diffusion only, we find CR reacceleration rates in good agreement with analytic predictions. When streaming is included, reacceleration rates depend on plasma β. Due to streaming-modified phase shifts between CR and gas variables, they are slower than canonical reacceleration rates in low-β environments like the interstellar medium but remain unchanged in high-β environments like the intracluster medium. We also quantify the streaming energy-loss rate in our simulations. For sub-Alfvénic turbulence, it is resolution dependent (hence unconverged in large-scale simulations) and heavily suppressed compared to the isotropic loss rate v A · ∇P CR/P CR ~ v A/L 0, due to misalignment between the mean field and isotropic CR gradients. Unlike acceleration efficiencies, CR losses are almost independent of magnetic field strength over β ~ 1-100 and are, therefore, not the primary factor behind lower acceleration rates when streaming is included. While this paper is primarily concerned with how turbulence affects CRs, in a follow-up paper we consider how CRs affect turbulence by diverting energy from the MHD cascade, altering the pathway to gas heating and steepening the turbulent spectrum.

Keywords: Cosmic rays, Plasma astrophysics, Galactic cosmic rays, Galaxies, Magnetohydrodynamical simulations
Grain Growth in the Dust Ring with a Crescent around the Very Low-mass Star ZZ Tau IRS with JVLA. The azimuthal asymmetries of dust rings in protoplanetary disks such as a crescent around young stars are often interpreted as dust traps, and thus as ideal locations for planetesimal and planet formations. Whether such dust traps effectively promote planetesimal formation in disks around very low-mass stars (VLM; a mass of ≲0.2 M ☉) is debatable, as the dynamical and grain growth timescales in such systems are long. To investigate grain growth in such systems, we studied the dust ring with a crescent around the VLM star ZZ Tau IRS using the Karl G. Jansky Very Large Array at centimeter wavelengths. Significant signals were detected around ZZ Tau IRS. To estimate the maximum grain size ( ${a}_{\max }$ ) in the crescent, we compared the observed spectral energy distribution (SED) with SEDs for various ${a}_{\max }$ values predicted by radiative transfer calculations. We found ${a}_{\max }\,\gtrsim $ 1 mm and ≲60 μm in the crescent and ring, respectively, though our modeling efforts rely on uncertain dust properties. Our results suggest that grain growth occurred in the ZZ Tau IRS disk, relative to the sub-micron-sized interstellar medium. Planet formation in a crescent with millimeter-sized pebbles might proceed more efficiently than in other regions with submillimeter-sized pebbles via pebble accretion scenarios.

Keywords: Protoplanetary disks
Curvature of Magnetic Field and Its Role on Plasma in Turbulent Magnetosheath. This study presents statistical features of magnetic field curvature in the magnetosheath region. Two sets of high-quality field and plasma data measured by the Magnetospheric Multiscale mission are analyzed by the multiple-point analysis method. The results include the following: (a) The probability distribution function (PDF) of the curvature exhibits two different power laws consistent with previous studies; the PDF of small curvatures depends on the plasma condition and the PDF of large curvatures shows better agreement. (b) The data validate the derived relation between the current density and the guiding center current as well as the diamagnetic current. (c) The acceleration due to curvature drifts in the perpendicular direction occurs when κ/κ rms is larger than 1, which is a potential mechanism for anisotropic distribution of plasma pressure at large curvatures.

Keywords: Space plasmas
X-Ray Spectroscopic Evidence of Charge Exchange Emission in the Disk of M51. In the disks of spiral galaxies, diffuse soft X-ray emission is known to be strongly correlated with star-forming regions. However, this emission is not simply from a thermal-equilibrium plasma and its origin remains greatly unclear. In this work, we present an X-ray spectroscopic analysis of the emission from the northern hot spot; a region with enhanced star formation off the nucleus of M51. Based on the high spectral resolution data from XMM-Newton/Reflection Grating Spectrometer (RGS) observations, we unambiguously detect a high G ratio ( ${3.2}_{-1.5}^{+6.9}$ ) of the O VII Heα triplet. This high G ratio is also spatially confirmed by oxygen emission-line maps from the same data. A physical model consisting of a thermal plasma and its charge exchange (CX) with neutral cool gas gives a good explanation for the G ratio and the entire RGS spectra. This model also gives a satisfactory characterization of the complementary Chandra ACIS-S data, which enables a direct imaging of the diffuse emission, tracing the hot plasma across the galaxy. The hot plasma has a similar characteristic temperature of ~0.34 keV and an approximately solar metallicity. The CX contributes ~50% to the diffuse emission in the 0.4-1.8 keV band, suggesting an effective hot/cool gas interface area about five times the geometric area of the M51 disk. Therefore, the CX appears to play a major role in the soft X-ray production and may be used as a powerful tool to probe the interface astrophysics, important for studying galactic ecosystems.

Keywords: High resolution spectroscopy, Stellar feedback, Spiral galaxies, Diffuse radiation, X-ray observatories