adsabs/SciX_UAT_keywords huggingface dataset:
Measuring the Gravitomagnetic Distortion from Rotating Halos. I. Methods

Source galaxy images are distorted not only by a static gravitational potential, but also by frame-dragging induced by massive rotating objects like clusters of galaxies. Such an effect is well understood theoretically; it is therefore of great interest to estimate its detectability for future surveys. In this work, we analyze the lensing convergence κ around rotating dark matter halos. The rotation of the massive objects generates a gravitomagnetic potential giving rise to an anisotropic contribution to the lensing potential. We construct an estimator δκ to describe the difference between the symmetric enhancement and reduction of κ around the halo rotation axis, finding that it is well approximated by a function proportional to the halo velocity dispersion squared times a dimensionless angular momentum parameter. Using simulation mocks with realistic noise level for a survey like the Legacy Survey of Space and Time (LSST), we test our estimator, and show that the signal from frame-dragging of stacked rotating lenses is consistent with zero within 1σ. However, we find that the most massive cluster in SDSS DR7 spectroscopic selected group catalog has a line-of-sight rotation velocity of 195.0 km s-1 and velocity dispersion of 667.8 km s-1, which is at 1.2 × 10-8 odds according to the angular momentum probability distribution inferred from N-body simulations. By studying SDSS DR7 spectroscopic selected group catalog, we show how rotating clusters can be identified, and, finding that fast rotating clusters might be more abundant than in estimates based on simulations, a detection of gravitomagnetic distortion may be at reach in future surveys.

Keywords: galaxy clusters; general relativity
Variability of the Great Disk Shadow in Serpens

We present dual-epoch Hubble Space Telescope imaging of the great disk shadow in the Serpens star-forming region. The near-infrared images show strong variability of the disk shadow, revealing dynamics of the inner disk on timescales of months. The Great Shadow is projected onto the Serpens reflection nebula by an unresolved protoplanetary disk surrounding the young intermediate-mass star SVS2/CK3/EC82. Since the shadow extends out to a distance of at least 17,000 au, corresponding to a light-travel time of 0.24 yr, the images may reveal detailed changes in the disk scale height and position angle on timescales as short as a day, corresponding to the angular resolution of the images, and up to the 1.11 yr span between two observing epochs. We present a basic retrieval of temporal changes in the disk density structure, based on the images. We find that the inner disk changes position angle on timescales of months, and that the change is not axisymmetric, suggesting the presence of a non-axisymmetric dynamical forcing on ∼1 au size scales. We consider two different scenarios, one in which a quadrupolar disk warp orbits the central star, and one in which an unequal-mass binary orbiting out of the disk plane displaces the photocenter relative to the shadowing disk. Continued space-based monitoring of the great disk shadow is required to distinguish between these scenarios, and could provide unique and detailed insight into the dynamics of inner protoplanetary disks not available through other means.

Keywords: protoplanetary disks; reverberation mapping; exoplanet formation
Limb and Gravity-darkening Coefficients for the Space Mission CHEOPS

The goal of this Research Note is to provide the theoretical calculations of the limb-darkening coefficients and gravity-darkening coefficients (GDC) for the space mission CHEOPS. We use two stellar atmosphere models: ATLAS (plane-parallel) and PHOENIX with spherical symmetry covering a wide range of effective temperatures, local gravities, and hydrogen/metal. These grids cover 19 metallicities ranging from 10-5 up to 10+1 solar abundances, 0 ≤ log g ≤ 6.0 and 2300 K ≤ Teff ≤ 50,000 K. The specific intensity distribution was fitted using six approaches: linear, quadratic, square root, logarithmic, power-2, and a series with four terms. The calculations of the GDC were performed for both stellar atmosphere models adopting an improved formulation.

Keywords: stellar atmospheres
A Nearby Isolated Dwarf: Star Formation and Structure of ESO 006-001

Observations with the Hubble Space Telescope unexpectedly revealed that the dwarf galaxy ESO 006-001 is a near neighbor to the Local Group at a distance of 2.70 ± 0.11 Mpc. The stellar population in the galaxy is well resolved into individual stars to a limit of M I ~ - 0.5 mag. The dominant population is older than 12 Gyr yet displays a significant range in metallicity of -2 < [Fe/H] < - 1, as evidenced by a red giant branch with substantial width. Superimposed on the dominant population are stars on the main sequence with ages less than 100 Myr and helium burning blue loop stars with ages of several hundred Myr. ESO 006-001 is an example of a transition dwarf; a galaxy dominated by old stars but one that has experienced limited recent star formation in a swath near the center. No H I gas is detected at the location of the optical galaxy in spite of the evidence for young stars. Intriguingly, an H I cloud with a similar redshift is detected 9 kpc away in projection. Otherwise, ESO 006-001 is a galaxy in isolation with its nearest known neighbor IC 3104, itself a dwarf, at a distance of ~500 kpc.

Keywords: dwarf galaxies; galaxy stellar content
Rate Coefficients for Dielectronic Recombination of Carbon-like 40Ca14+

Dielectronic recombination (DR) rate coefficients for carbon-like 40Ca14+ forming nitrogen-like 40Ca13+ have been measured using the electron-ion merged-beam technique at the heavy-ion storage ring CSRm at the Institute of Modern Physics in Lanzhou, China. The measured DR rate coefficients in the energy range from 0 to 92 eV cover most of the DR resonances associated with 2s22p2 → 2s22p2 and 2s22p2 → 2s2p3 core transitions (ΔN = 0). Theoretical calculations of the DR cross sections were carried out by using two different state-of-the-art atomic theoretical techniques, multiconfiguration Breit-Pauli (MCBP) code AUTOSTRUCTURE and relativistic configuration interaction code FAC, to compare with the experimental rate coefficients. The theoretical calculations agree with the experimental results at collision energy higher than 10 eV. However, significant discrepancies of resonance energies and strengths can be found at collision energy below 8 eV. Temperature-dependent plasma recombination rate coefficients were derived from the measured DR rate coefficients in the energy range from 0.1 to 1000 eV and compared with the recommended atomic data from the literature. The theoretical data of Gu et al. and Zatsarinny et al. are 30% lower than the experimental results at the temperatures of photoionized plasmas, but have a very good agreement at the temperatures of collisionally ionized plasmas. Other previously published theoretical data of Jacobs et al. and Mazzotta et al. by using Burgess formula and LS-coupling calculations significantly underestimate the plasma rate coefficients in the low temperature range. The present results comprise a set of benchmark data suitable for astrophysical modeling.

Keywords: atomic spectroscopy; spectroscopy; atomic data benchmarking; atomic physics
An EUV Jet Driven by a Series of Transition Region Microjets

Jets are one of the most common eruptive events in the solar atmosphere, and they are believed to be important in the context of coronal heating and solar wind acceleration. We present an observational study on a sequence of jets with the data acquired with the Solar Dynamics Observatory and the Interface Region Imaging Spectrograph. This sequence is peculiar in that an extreme-ultraviolet (EUV) jet, ~29″ long and with a dome-like base, appears to be a consequence of a series of transition region (TR) microjets that are a few arcsecs in length. We find that the occurrence of any TR microjets is always associated with the change of geometry of microloops at the footpoints of the microjets. A bundle of TR flux ropes is seen to link a TR microjet to the dome-like structure at the base of the EUV jet. This bundle rises as a response to the TR microjets, with the rising motion eventually triggering the EUV jet. We propose a scenario involving a set of magnetic reconnections, in which the series of TR microjets are associated with the processes to remove the constraints to the TR flux ropes and thus allows them to rise and trigger the EUV jet. Our study demonstrates that small-scale dynamics in the lower solar atmosphere are crucial in understanding the energy and mass connection between the corona and the solar lower atmosphere, even though many of them might not pump mass and energy to the corona directly.

Keywords: solar coronal transients; solar corona; active solar corona; solar transition region; solar magnetic reconnection; plasma jets; solar atmosphere
Temperature Spectra of Interstellar Dust Grains Heated by Cosmic Rays. III. Mixed-composition Grains

Icy grains in the interstellar medium and star formation regions consist of a variety of materials. Such composite grains interact differently with cosmic-ray (CR) particles compared to simple single-material grains. We aim to calculate the spectra of energies and temperatures of mixed-composition grains undergoing whole-grain heating by CRs. The grains were assumed to consist of a mixture of carbon and olivine, covered by ices consisting of carbon oxides and water. The energy and temperature spectra for grains with radii 0.05, 0.1, and 0.2 μm impacted by CRs were calculated for eight values of column density, relevant to molecular clouds and star-forming cores. The approach takes into account changes in ice thickness and composition with increasing column density. These detailed data for CR interaction with interstellar grains are intended for applications in astrochemical models. The main finding is that a more accurate approach on grain heat capacity and other factors prevent frequent heating of 0.1 μm or larger icy grains to high temperatures.

Keywords: cosmic rays; astrochemistry; interstellar dust; interstellar molecules; dark interstellar clouds
The Downwind Solar Wind: Model Comparison with Pioneer 10 Observations

The solar wind in the upwind region has been well modeled using a pickup ion (PUI) mediated MHD model (Zank et al.). It suggests that PUIs have an important role in heating the solar wind in the outer heliosphere. However, the solar wind in the downwind region is not as well understood. Here, we compare the Zank et al. model with Pioneer 10 observations, which allows us to investigate the downwind solar wind out to 60 au. We use a model in which the hydrogen temperature is finite to obtain a proper hydrogen number density distribution in the downwind region and incorporate it into the model. Our results explain Pioneer 10 observations well and indicate that the heating due to PUIs is less effective than in the upwind region since the density of PUIs in the downwind region is less than the upwind PUIs density. We also derive parameters at several possible locations of the downwind termination shock.

Keywords: solar wind; solar physics; magnetohydrodynamics; pickup ions
The High-mass X-Ray Binary Luminosity Functions of Dwarf Galaxies

Drawing from the Chandra archive and using a carefully selected set of nearby dwarf galaxies, we present a calibrated high-mass X-ray binary (HMXB) luminosity function in the low-mass galaxy regime and search for an already hinted at dependence on metallicity. Our study introduces a new sample of local dwarf galaxies (D < 12.5 Mpc and M * < 5 × 109 M ⊙), expanding the specific star formation rates (sSFR) and gas-phase metallicities probed in previous investigations. Our analysis of the observed X-ray luminosity function indicates a shallower power-law slope for the dwarf galaxy HMXB population. In our study, we focus on dwarf galaxies that are more representative in terms of sSFR compared to prior work. In this regime, the HMXB luminosity function exhibits significant stochastic sampling at high luminosities. This likely accounts for the pronounced scatter observed in the galaxy-integrated HMXB population's L X/SFR versus metallicity for our galaxy sample. Our calibration is necessary to understand the active galactic nuclei content of low-mass galaxies identified in current and future X-ray survey fields and has implications for binary population synthesis models, as well as X-ray-driven cosmic heating in the early Universe.

Keywords: high mass x-ray binary stars; metallicity; star formation; dwarf galaxies; x-ray binary stars; x-ray astronomy; compact objects
Influence of the Lower Atmosphere on Wave Heating and Evaporation in Solar Coronal Loops

We model a coronal loop as a 3D magnetic cylinder in a realistic solar atmosphere that extends from the chromosphere to the corona. Kink oscillations, believed to be ubiquitous in the solar corona, are launched in the loop. Heating is expected owing to the dissipation of wave energy at small structures that develop from the Kelvin-Helmholtz instability induced by kink oscillations. Increases in temperature and internal energy can be observed in the coronal counterpart of the driven loop. With the presence of thermal conduction, chromospheric evaporation can also be seen. Although the volume-averaged temperature and density changes seem slight (~4% relative to a nondriven loop), the enthalpy flow from the lower atmosphere redistributes the density and temperature in the vertical direction, thus enhancing the dissipation of wave energy in the corona. The efficient heating in the coronal counterpart of the loop can complement the thermal conductive losses shown in the current model and thus maintain the internal energy in the corona.

Keywords: magnetohydrodynamics; solar coronal waves
BatAnalysis: A Comprehensive Python Pipeline for Swift BAT Survey Analysis

The Swift Burst Alert Telescope (BAT) is a coded-aperture gamma-ray instrument with a large field of view that primarily operates in survey mode when it is not triggering on transient events. The survey data consist of 80-channel detector plane histograms that accumulate photon counts over periods of at least 5 minutes. These histograms are processed on the ground and are used to produce the survey data set between 14 and 195 keV. Survey data comprise >90% of all BAT data by volume and allow for the tracking of long-term light curves and spectral properties of cataloged and uncataloged hard X-ray sources. Until now, the survey data set has not been used to its full potential due to the complexity associated with its analysis and the lack of easily usable pipelines. Here, we introduce the BatAnalysis Python package, a wrapper for HEASoftpy, which provides a modern, open-source pipeline to process and analyze BAT survey data. BatAnalysis allows members of the community to use BAT survey data in more advanced analyses of astrophysical sources, including pulsars, pulsar wind nebula, active galactic nuclei, and other known/unknown transient events that may be detected in the hard X-ray band. We outline the steps taken by the Python code and exemplify its usefulness and accuracy by analyzing survey data of the Crab Nebula, NGC 2992, and a previously uncataloged MAXI transient. The BatAnalysis package allows for ~18 yr of BAT survey data to be used in a systematic way to study a large variety of astrophysical sources.

Keywords: astronomy data analysis; astronomy data acquisition; open source software
Continued PSP/WISPR Observations of a Phaethon-related Dust Trail

We present an update to the first white-light detections of a dust trail observed closely following the orbit of asteroid (3200) Phaethon, as seen by the Wide-field Imager for the Parker Solar Probe instrument on the NASA Parker Solar Probe mission. Here, we provide a summary and analysis of observations of the dust trail over nine separate mission encounters between 2018 October and 2021 August that saw the spacecraft approach to within 0.0277 au of the orbit of Phaethon. We find the photometric and estimated dust mass properties to be in line with those in the initial publication, with a visual (V) magnitude of V ~ 16.1 ± 0.3 pixel-1, corresponding to a surface brightness of 26.1 mag arcsec-2, and an estimated mass of dust within the range 1010-1012 kg depending on the assumed dust properties. However, the key finding of this survey is the discovery that the dust trail does not perfectly follow the orbit of Phaethon, with a clear separation noted between them that increases as a function of true anomaly, though the trail may differ from Phaethon's orbit by as little as 1° in periapsis.

Keywords: asteroids; meteoroid dust clouds; near-earth objects; small solar system bodies
Magnetic Field Dropouts and Associated Plasma Wave Emission near the Electron Plasma Frequency at Switchback Boundaries as Observed by the Parker Solar Probe

The first solar encounters by the Parker Solar Probe revealed the magnetic field to be dominated by short field reversals in the radial direction, referred to as "switchbacks." While radial velocity and proton temperature were shown to increase inside the switchbacks, ∣B∣ exhibits very brief dropouts only at the switchback boundaries. Brief intensifications in spectral density measurements near the electron plasma frequency, f pe, were also observed at these boundaries, indicating the presence of plasma waves triggered by current systems in the form of electron beams. We perform a correlative study using observations from the Parker FIELDS Radio Frequency Spectrometer and Fluxgate Magnetometer to compare occurrences of spectral density intensifications at the electron plasma frequency (f pe emissions) and ∣B∣ dropouts at switchback boundaries during Parker's first and second solar encounters. We find that only a small fraction of minor ∣B∣ dropouts are associated with f pe emissions. This fraction increases with ∣B∣ dropout size until all dropouts are associated with f pe emissions. Brief spikes in the differential electron flux measured by the SWEAP Solar Probe Analyzer for Electron sensors also occur in conjunction with nearly all f pe emissions. This suggests that in the presence of strong ∣B∣ dropouts, electron currents that create the perturbation in ∣B∣ along the boundaries are also stimulating plasma waves such as Langmuir waves.

Keywords: solar magnetic fields; plasma physics; solar wind
Dust Mass Associated with the Supernova Remnant IC 443 When Emission Meets Extinction

The dust mass of the well-known supernova remnant IC 443 is estimated from both the infrared emission and the visual extinction. With photometry to the images taken by Spitzer, WISE, IRAS, AKARI, and Planck, the spectral energy distribution (SED) of the dust is obtained after subtracting synchrotron radiation and considering the spectral line emission. The dust mass is derived by fitting the SED with a two-component model, which results in a warm component with a temperature of ~53 K and mass of 0.1 M ⊙ and a cold component with a temperature of ~17 K and mass of 46 M ⊙. On the other hand, the dust mass is derived to be ~66 M ⊙ from the visual extinction of IC 443, which is identified from the 3D Bayestar extinction map and its coincidence with the infrared emission morphology. The dust mass derived from the infrared emission is in rough agreement with that derived from extinction. However, the two can be adjusted to be more consistent by using a different dust opacity or by considering optically thick radiation. In addition, the distribution of dust temperature and mass is analyzed by fitting the SED pixel-by-pixel.

Keywords: supernova remnants; interstellar dust; interstellar extinction; dust continuum emission
Mira Ceti, Atypical Archetype

With the aim of unraveling the complexity of the morphokinematics of the circumstellar envelope (CSE) of Mira Ceti, we review, extend, and in some cases revisit Atacama Large Millimeter/submillimeter Array observations of the emission of the SiO(5-4) and CO(3-2) molecular lines. In addition, we present a detailed analysis of the optically thin 13CO(3-2) emission, which provides several important new results. In agreement with observations at infrared and visible wavelengths, we give evidence for the confinement and probably rotation of a dense gas volume within ~50 au from the star and for a large SiO line width within ~15 au. We show that the mass-loss process is episodic and takes the form of clumps having a very low SiO/CO abundance ratio compared with similar oxygen-rich long-period variables, probably a result of depletion on dust grains and photodissociation. We evaluate the mass-loss rate associated with the main clumps and compare it with values obtained from single-dish observations. We argue that the SiO emission observed in the southwestern quadrant is not related to the mechanism of generation of the nascent wind but to a mass ejection that occurred 11 years before the observations. We remark that Mira Ceti is not a good archetype in terms of its wind: models aiming at describing the very complex gas-dust chemistry in action in the CSE of oxygen-rich AGB stars may find it difficult to account for its peculiar features and small variations in the parameters deciding when and where mass loss can proceed significantly.

Keywords: asymptotic giant branch stars; circumstellar matter
Measuring the Mass and Concentration of Dark Matter Halos from the Velocity Dispersion Profile of their Stars

We use the IllustrisTNG (TNG) simulations of galaxy formation to measure the velocity dispersion profiles of dark matter and stars in Milky Way-mass, galaxy group, and cluster-scale dark matter halos. The mean profiles calculated from both tracers are similar in shape, exhibiting a large halo-to-halo scatter around the average profile. The so-called "splashback" radius demarcates the outer boundary of the halo, and manifests as a kink in the velocity dispersion profile, located on average between ∼1.0-1.5r200m, where r200m is the radius within which the density of the halo equals 200 times the background density of the universe. We find that this location may also be identified as the radius at which the (stacked) dispersion profile drops to 60% of its peak value (for line-of-sight motions in TNG halos). We further show that the scatter in the dispersion profiles may be attributed to the variations in the assembly history of the host halos. In particular, this segregates the profile into two regimes: one within ∼0.1r200m, where the scatter is set by the early assembly history of the halo; and the other beyond this radius, where the scatter is influenced more strongly by its late-time assembly. Finally, we show that a two-parameter model can be used to fit the measured velocity dispersion profiles and the fit parameters can be related directly to two fundamental halo properties: mass and concentration. We describe a simple model that allows us to express the stellar velocity dispersion profile in terms of these halo properties only.

Keywords: cosmology; galaxy formation