adsabs/SciX_UAT_keywords huggingface dataset:
Molecular Gas Outflow in the Starburst Galaxy NGC 1482

Galactic winds are essential to the regulation of star formation in galaxies. To study the distribution and dynamics of molecular gas in wind, we imaged the nearby starburst galaxy NGC 1482 in CO (J = 1 → 0) at a resolution of 1″ (≈100 pc) using the Atacama Large Millimeter/submillimeter Array. Molecular gas is detected in a nearly edge-on disk with a radius of 3 kpc and a biconical outflow emerging from the central 1 kpc starburst and extending to at least 1.5 kpc perpendicular to the disk. In the outflow, CO gas is distributed approximately as a cylindrically symmetrical envelope surrounding the warm and hot ionized gas traced by Hα and soft X-rays. The velocity, mass outflow rate, and kinetic energy of the molecular outflow are ${v}_{{\rm{w}}}\sim 100\,\mathrm{km}\,{{\rm{s}}}^{-1}$ , ${\dot{M}}_{{\rm{w}}}\sim 7\,{M}_{\odot }\,{\mathrm{yr}}^{-1}$ , and ${E}_{{\rm{w}}}\sim 7\times {10}^{54}\,\mathrm{erg}$ , respectively. ${\dot{M}}_{{\rm{w}}}$ is comparable to the star formation rate ( ${\dot{M}}_{{\rm{w}}}/\mathrm{SFR}\sim 2$ ) and Ew is ∼1% of the total energy released by stellar feedback in the past $1\times {10}^{7}\,\mathrm{yr}$ , which is the dynamical timescale of the outflow. The results indicate that the wind is starburst driven.

Keywords: starburst galaxies; molecular gas; galactic winds; galaxy evolution; star formation; stellar feedback; galaxy fountains; galaxy kinematics; interstellar phases; cold neutral medium
Binary Natal Kicks in the Galactic Center: X-Ray Binaries, Hypervelocity Stars, and Gravitational Waves

Theoretical and observational studies suggest that stellar binaries exist in large numbers in galactic nuclei like our own Galactic Center. Neutron stars (NSs), and debatedly, black holes and white dwarfs, receive natal kicks at birth. In this work, we study the effect of two successive natal kicks on a population of stellar binaries orbiting the massive black hole (MBH) in our Galactic Center. These natal kicks can significantly alter the binary orbit in a variety of ways, and also the orbit of the binary around the MBH. We found a variety of dynamical outcomes resulting from these kicks, including a steeper cusp of single NSs relative to the initial binary distribution. Furthermore, hypervelocity star and binary candidates, including hypervelocity X-ray binaries, are a common outcome of natal kicks. In addition, we show that the population of X-ray binaries in the Galactic Center can be used as a diagnostic for the BH natal kick distribution. Finally, we estimate the rate of gravitational wave events triggered by natal kicks, including binary mergers and EMRIs.

Keywords: galactic center; stellar dynamics; supernova dynamics; x-ray binary stars; hypervelocity stars; gravitational waves
I Spy Transits and Pulsations: Empirical Variability in White Dwarfs Using Gaia and the Zwicky Transient Facility

We present a novel method to detect variable astrophysical objects and transient phenomena using anomalous excess scatter in repeated measurements from public catalogs of Gaia DR2 and Zwicky Transient Facility (ZTF) DR3 photometry. We first provide a generalized, all-sky proxy for variability using only Gaia DR2 photometry, calibrated to white dwarf stars. To ensure more robust candidate detection, we further employ a method combining Gaia with ZTF photometry and alerts. To demonstrate its efficacy, we apply this latter technique to a sample of roughly 12,100 white dwarfs within 200 pc centered on the ZZ Ceti instability strip, where hydrogen-atmosphere white dwarfs are known to pulsate. By inspecting the top 1% of the samples ranked by these methods, we demonstrate that both the Gaia-only and ZTF-informed techniques are highly effective at identifying known and new variable white dwarfs, which we verify using follow-up, high-speed photometry. We confirm variability in all 33 out of 33 (100%) observed white dwarfs within our top 1% highest-ranked candidates, both inside and outside the ZZ Ceti instability strip. In addition to dozens of new pulsating white dwarfs, we also identify five white dwarfs highly likely to show transiting planetary debris; if confirmed, these systems would more than triple the number of white dwarfs known to host transiting debris.

Keywords: white dwarf stars; variable stars; stellar pulsations; zz ceti stars; transits; planetesimals; circumstellar dust; transient detection; cataclysmic variable stars
Thermodynamic and Magnetic Topology Evolution of the X1.0 Flare on 2021 October 28 Simulated by a Data-driven Radiative Magnetohydrodynamic Model

Solar filament eruptions, flares, and coronal mass ejections (CMEs) are manifestations of drastic releases of energy in the magnetic field, which are related to many eruptive phenomena, from the Earth's magnetosphere to black hole accretion disks. With the availability of high-resolution magnetograms on the solar surface, observational data-based modeling is a promising way to quantitatively study the underlying physical mechanisms behind observations. By incorporating thermal conduction and radiation losses in the energy equation, we develop a new data-driven radiative magnetohydrodynamic model, which has the capability of capturing the thermodynamic evolution compared to our previous zero-β model. Our numerical results reproduce the major observational characteristics of the X1.0 flare on 2021 October 28 in NOAA active region 12887, including the morphology of the eruption, the kinematics of the flare ribbons, extreme ultraviolet (EUV) radiations, and the two components of the EUV waves predicted by the magnetic stretching model, i.e., a fast-mode shock wave and a slower apparent wave, due to successive stretching of the magnetic field lines. Moreover, some intriguing phenomena are revealed in the simulation. We find that flare ribbons separate initially and ultimately stop at the outer stationary quasi-separatrix layers (QSLs). Such outer QSLs correspond to the border of the filament channel and determine the final positions of flare ribbons, which can be used to predict the size and the lifetime of a flare before it occurs. In addition, the side views of the synthesized EUV and white-light images exhibit typical three-part structures of CMEs, where the bright leading front is roughly cospatial with the nonwave component of the EUV wave, reinforcing the use of the magnetic stretching model for the slow component of EUV waves.

Keywords: solar prominences; solar coronal mass ejections; solar flares; solar magnetic fields; radiative magnetohydrodynamics
Parallax Effect in Microlensing Events Due to Free-floating Planets

One of the most important applications of microlensing observations is the detection of free-floating planets (FFPs). The timescale of microlensing due to FFPs (t E) is short (a few days). Discerning the annual parallax effect in observations of these short-duration events due to FFPs by one observer is barely possible, though their parallax amplitude is larger than that in common events. In microlensing events due to FFPs, the lens–source relative trajectory alters because of the observer's motion by δ u . This deviation is a straight line as long as t E ≪ P ⊕, and its size is δ u ∝ π rel (P ⊕ is the observer's orbital period). So, most observed microlensing events due to close FFPs have simple Paczyńsky light curves with indiscernible but important parallax. To evaluate the destructive effects of invisible parallax in such events, we simulate ∼9650 microlensing events due to FFPs with t E < 10 days that are observed only by the Nancy Grace Roman Space Telescope (Roman). We conclude that in half of these microlensing events the missing parallax alters the real light curves, changing their shape and derived properties (by Δχ 2 ≳ 100). By fitting Paczyński light curves to these affected events we evaluate the relative and dimensionless deviations in the lensing parameters from their real values (δ t E, δ ρ ⋆, ...). We conclude that around 46 FFPs that are discovered by Roman have light curves highly affected by invisible parallax with δ t E > 0.1 and δ ρ ⋆ > 0.1. Our study reveals the importance of simultaneous and dense observations of the same microlensing events viewed by Roman by other observers circling the Sun in different orbits.

Keywords: gravitational microlensing exoplanet detection; microlensing parallax; gravitational microlensing; annual microlensing parallax; free floating planets
On the Chromaticity of the (NEO)WISE Astrometry

The Wide-field Infrared Survey Explorer and its follow-up Near-Earth Object (NEO) mission scan the mid-infrared sky twice a year. The spatial and temporal coverage of the resulting database is of utmost importance for variability studies, in particular of young stellar objects which have red W1 ‑ W2 colors. During such an effort, I noticed subarcsecond position offsets between subsequent visits. The offsets do not appear for targets with small W1 ‑ W2 colors, which points to a chromatic origin in the optics, caused by the spacecraft pointing alternating "forward" and "backward" from one visit to another. It amounts to 0.″1 for targets with W1 ‑ W2 ≈ 2. Consideration of this chromatic offset will improve astrometry. This is of particular importance for NEOs that are generally red.

Keywords: astrometry; sky surveys; young stellar objects; near-earth objects
Revisiting the Revisited Palmer Consensus: New Insights from Jovian Electron Transport

Novel insights into the behavior of the diffusion coefficients of charged particles in the inner heliosphere are of great importance to any study of the transport of these particles and are especially relevant with regard to the transport of low-energy electrons. The present study undertakes an exhaustive investigation into the diffusion parameters needed to reproduce low-energy electron intensities as observed at Earth, using a state-of-the-art 3D cosmic ray transport code. To this end, the transport of Jovian electrons is considered, as Jupiter represents the predominant source of these particles in the inner heliosphere, and because a careful comparison of model results with observations taken during periods of good and poor magnetic connectivity between Earth and Jupiter allows for conclusions to be drawn as to both parallel and perpendicular diffusion coefficients. This study then compares these results with the predictions made by various scattering theories. Best-fit parameters for parallel and perpendicular mean free paths at 1 au fall reasonably well within the span of observational values reported by previous studies, but best-fit radial and rigidity dependences vary widely. However, a large number of diffusion parameters lead to reasonable to-good fits to observations, and it is argued that considerable caution must be exercised when comparing theoretical results for diffusion coefficients with diffusion parameters calculated from particle transport studies.

Keywords: cosmic rays; cosmic ray sources; heliosphere; interplanetary turbulence
Probing Reflection from Aerosols with the Near-infrared Dayside Spectrum of WASP-80b

The presence of aerosols is intimately linked to the global energy budget and the composition of a planet's atmosphere. Their ability to reflect incoming light prevents energy from being deposited into the atmosphere, and they shape the spectra of exoplanets. We observed five near-infrared secondary eclipses of WASP-80b with the Wide Field Camera 3 (WFC3) aboard the Hubble Space Telescope to provide constraints on the presence and properties of atmospheric aerosols. We detect a broadband eclipse depth of 34 ± 10 ppm for WASP-80b. We detect a higher planetary flux than expected from thermal emission alone at 1.6σ, which hints toward the presence of reflecting aerosols on this planet's dayside, indicating a geometric albedo of A g < 0.33 at 3σ. We paired the WFC3 data with Spitzer data and explored multiple atmospheric models with and without aerosols to interpret this spectrum. Albeit consistent with a clear dayside atmosphere, we found a slight preference for near-solar metallicities and for dayside clouds over hazes. We exclude soot haze formation rates higher than 10-10.7 g cm-2s-1 and tholin formation rates higher than 10-12.0 g cm-2s-1 at 3σ. We applied the same atmospheric models to a previously published WFC3/Spitzer transmission spectrum for this planet and found weak haze formation. A single soot haze formation rate best fits both the dayside and the transmission spectra simultaneously. However, we emphasize that no models provide satisfactory fits in terms of the chi-square of both spectra simultaneously, indicating longitudinal dissimilarity in the atmosphere's aerosol composition.

Keywords: exoplanets; extrasolar gaseous planets; exoplanet atmospheres; exoplanet atmospheric composition
Uniform Distribution of the Extremely Overionized Plasma Associated with the Supernova Remnant G359.1-0.5

We report on the results of our detailed analyses on the peculiar recombining plasma of the supernova remnant (SNR) G359.1-0.5, and the interacting CO clouds. Combining Chandra and Suzaku data, we estimated the ionization state of the plasma with a careful treatment of the background spectrum. The average spectrum showed a remarkably large deviation of the electron temperature (∼0.17 keV) from the initial temperature (>16 keV), indicating that the plasma is in a highly recombination-dominant state. On the other hand, the recombination timescale (net) is comparable to those of the other recombining SNRs (∼4.2 × 1011 cm-3 s). We also searched for spatial variation of the plasma parameters, but found no significant differences. Using 12CO(J = 2-1) data obtained with NANTEN2, we found a new, plausible candidate for the interacting CO cloud, which has a line-of-sight velocity of ∼ -20 km s-1. This indicates that the SNR is located at a distance of ∼4 kpc, which is the foreground of the Galactic center, as previously reported. The associated CO cloud does not show clear spatial coincidence with the nearby GeV/TeV emission, indicating that the origins of the GeV/TeV emission are likely unrelated to G359.1-0.5.

Keywords: supernova remnants; interstellar medium; x-ray sources
Fundamental Reference AGN Monitoring Experiment (FRAMEx). I. Jumping Out of the Plane with the VLBA

We present the first results from the Fundamental Reference active galactic nucleus (AGN) Monitoring Experiment, an observational campaign dedicated to understanding the physical processes that affect the apparent positions and morphologies of AGNs. In this work, we obtained simultaneous Swift X-ray Telescope and Very Long Baseline Array (VLBA) radio observations for a snapshot campaign of 25 local AGNs that form a volume-complete sample with hard X-ray (14-195 keV) luminosities above 1042 erg s-1, out to a distance of 40 Mpc. Despite achieving an observation depth of ∼20 μJy, we find that 16 of 25 AGNs in our sample are not detected with the VLBA on milliarcsecond (subparsec) scales, and the corresponding core radio luminosity upper limits are systematically below predictions from the Fundamental Plane of black hole activity. Using archival Jansky Very Large Array (VLA) radio measurements, our sample jumps back onto the Fundamental Plane, suggesting that extended radio emission is responsible for the apparent correlation between radio emission, X-ray emission, and black hole mass. We suggest that this discrepancy is likely due to extranuclear radio emission produced via interactions between the AGN and host environment. We compare VLBA observations of AGNs to VLA observations of nearby Galactic black holes, and we find a mass-independent correlation between radio and X-ray luminosities of black holes of ${L}_{6\mathrm{cm}}$ / ${L}_{2-10\mathrm{keV}}$ ∼10-6, in line with predictions for coronal emission, but allowing for the possibility of truly radio-silent AGNs.

Keywords: active galactic nuclei; radio cores; x-ray active galactic nuclei; radio astrometry
Formation and Evolution of Transient Prominence Bubbles Driven by Erupting Minifilaments

Prominence bubbles, the dark arch-shaped voids below quiescent prominences, are generally believed to be caused by the interaction between the prominences and the slowly emerging or quasi-stable underlying magnetic loops. However, this scenario could not explain some short-lived bubbles with extremely dynamic properties of evolution. Based on high-resolution Hα observations, here we propose that bubbles should be classified into two categories according to their dynamic properties: quasi-steady Type-I bubbles and transient Type-II bubbles. Type-I bubbles could remain relatively stable and last for several hours, indicating the existence of a quasi-stable magnetic topology, while Type-II bubbles grow and collapse quickly within 1 hr without stability duration, which are usually associated with erupting minifilaments. Analysis of several typical Type-II bubbles from different views, especially including an on-disk event, reveals that Type-II bubbles quickly appear and expand at a velocity of ∼5–25 km s‑1 accompanied by an erupting minifilament below. The minifilament's rising velocity is slightly larger than that of the Type-II bubbles' boundary, which will lead to the collision with each other in a short time, subsequent collapse of Type-II bubbles, and formation of a large plume into the above prominence. We also speculate that only if the angle between the axis of the erupting minifilament and the line of sight is large enough, the interaction between the erupting minifilament and the overlying prominence could trigger a Type-II bubble with a typical arch-shaped but quickly expanding bright boundary.

Keywords: solar activity; solar atmosphere; solar magnetic fields; solar prominences; solar filament eruptions
Decoding the X-Ray Flare from MAXI J0709-159 Using Optical Spectroscopy and Multiepoch Photometry

We present a follow-up study on the recent detection of two X-ray flaring events by MAXI/Gas Slit Camera observations in soft and hard X-rays from MAXI J0709-159 in the direction of HD 54786 (LY CMa), on 2022 January 25. The X-ray luminosity during the flare was around 1037 erg s-1 (MAXI), which got reduced to 1032 erg s-1 (NuSTAR) after the flare. We took low-resolution spectra of HD 54786 from the 2.01 m Himalayan Chandra Telescope and the 2.34 m Vainu Bappu Telescope (VBT) facilities in India, on 2022 February 1 and 2. In addition to Hα emission, we found emission lines of He I in the optical spectrum of this star. By comparing our spectrum of the object with those from the literature we found that He I lines show variability. Using photometric studies we estimate that the star has an effective temperature of 20,000 K. Although HD 54786 is reported as a supergiant in previous studies, our analysis favors it to be evolving off the main sequence in the color-magnitude diagram. We could not detect any infrared excess, ruling out the possibility of IR emission from a dusty circumstellar disk. Our present study suggests that HD 54786 is a Be/X-ray binary system with a compact object companion, possibly a neutron star.

Keywords: be stars; spectroscopy; x-ray sources; x-ray binary stars
Measurements of the Dust Properties in z ≃ 1-3 Submillimeter Galaxies with ALMA

We present Atacama Large Millimeter/submillimeter Array (ALMA) 2 mm continuum observations of a complete and unbiased sample of 99 870 μm selected submillimeter galaxies (SMGs) in the Extended Chandra Deep Field South (ALESS). Our observations of each SMG reach average sensitivities of 53 μJy beam-1. We measure the flux densities for 70 sources, for which we obtain a typical 870 μm-to-2 mm flux ratio of 14 ± 5. We do not find a redshift dependence of this flux ratio, which would be expected if the dust emission properties of our SMGs were the same at all redshifts. By combining our ALMA measurements with existing Herschel/SPIRE observations, we construct a (biased) subset of 27 galaxies for which the cool dust emission is sufficiently well sampled to obtain precise constraints on their dust properties using simple isothermal models. Thanks to our new 2 mm observations, the dust emissivity index is well constrained and robust against different dust opacity assumptions. The median dust emissivity index of our SMGs is β ≃ 1.9 ± 0.4, consistent with the emissivity index of dust in the Milky Way and other local and high-redshift galaxies, as well as classical dust-grain model predictions. We also find a negative correlation between the dust temperature and β, similar to low-redshift observational and theoretical studies. Our results indicate that β ≃ 2 in high-redshift dusty star-forming galaxies, implying little evolution in dust-grain properties between our SMGs and local dusty galaxy samples, and suggesting that these high-mass and high-metallicity galaxies have dust reservoirs driven by grain growth in their interstellar medium.

Keywords: submillimeter astronomy; high-redshift galaxies; interstellar medium
Bayesian Inference of Strange Star Equation of State Using the GW170817 and GW190425 Data

The observations of compact star inspirals from LIGO/Virgo provide a valuable tool to study the highly uncertain equation of state (EOS) of dense matter at the densities in which the compact stars reside. It is not clear whether the merging stars are neutron stars or quark stars containing self-bound quark matter. In this work, we explore the allowed bag-model-like EOSs by assuming the merging stars are strange quark stars (SQSs) from a Bayesian analysis employing the tidal deformability observational data of the GW170817 and GW190425 binary mergers. We consider two extreme states of strange quark matter, either nonsuperfluid or color-flavor locked (CFL) and find the results in these two cases essentially reconcile. In particular, our results indicate that the sound speed in the SQS matter is approximately a constant close to the conformal limit of $c/\sqrt{3}$ . The universal relations between the mass, the tidal deformability, and the compactness are provided for the SQSs. The most probable values of the maximum mass are found to be ${M}_{\mathrm{TOV}}={2.10}_{-0.12}^{+0.12}\,({2.15}_{-0.14}^{+0.16})\,{M}_{\odot }$ for normal (CFL) SQSs at a 90% confidence level. The corresponding radius and tidal deformability for a 1.4 M⊙ star are ${R}_{1.4}={11.50}_{-0.55}^{+0.52}\,({11.42}_{-0.44}^{+0.52})\,\mathrm{km}$ and ${{\rm{\Lambda }}}_{1.4}={650}_{-190}^{+230}\,({630}_{-150}^{+220})$ , respectively. We also investigate the possibility of GW190814's secondary component m2 of mass ${2.59}_{-0.09}^{+0.08}\,{M}_{\odot }$ being an SQS, and find that it could be a CFL SQS with the pairing gap Δ larger than 244 MeV and the effective bag parameter ${B}_{\mathrm{eff}}^{1/4}$ in the range of 170-192 MeV, at a 90% confidence level.

Keywords: compact objects; gravitational waves; high energy astrophysics