adsabs/SciX_UAT_keywords huggingface dataset:
Observational Inference on the Delay Time Distribution of Short Gamma-Ray Bursts

The delay time distribution of neutron star mergers provides critical insights into binary evolution processes and the merger rate evolution of compact object binaries. However, current observational constraints on this delay time distribution rely on the small sample of Galactic double neutron stars (with uncertain selection effects), a single multimessenger gravitational wave event, and indirect evidence of neutron star mergers based on r-process enrichment. We use a sample of 68 host galaxies of short gamma-ray bursts to place novel constraints on the delay time distribution and leverage this result to infer the merger rate evolution of compact object binaries containing neutron stars. We recover a power-law slope of $\alpha =-{1.83}_{-0.39}^{+0.35}$ (median and 90% credible interval) with α < -1.31 at 99% credibility, a minimum delay time of ${t}_{\min }={184}_{-79}^{+67}\,\mathrm{Myr}$ with ${t}_{\min }\gt 72\,\mathrm{Myr}$ at 99% credibility, and a maximum delay time constrained to ${t}_{\max }\gt 7.95\,\mathrm{Gyr}$ at 99% credibility. We find these constraints to be broadly consistent with theoretical expectations, although our recovered power-law slope is substantially steeper than the conventional value of α = -1, and our minimum delay time is larger than the typically assumed value of 10 Myr. Pairing this cosmological probe of the fate of compact object binary systems with the Galactic population of double neutron stars will be crucial for understanding the unique selection effects governing both of these populations. In addition to probing a significantly larger redshift regime of neutron star mergers than possible with current gravitational wave detectors, complementing our results with future multimessenger gravitational wave events will also help determine if short gamma-ray bursts ubiquitously result from compact object binary mergers.

Keywords: gamma-ray bursts; gravitational wave sources; compact binary stars
Photometry of 10 Million Stars from the First Two Years of TESS Full Frame Images: Part II

We present light curves from a magnitude limited set of stars and other stationary luminous objects from the TESS Full Frame Images, as reduced by the MIT Quick Look Pipeline (QLP). Our light curves cover the full two-year TESS Primary Mission and include ∼14,770,000 and ∼9,600,000 individual light curve segments in the Southern and Northern ecliptic hemispheres, respectively. We describe the detrending techniques we used to create the light curves, and compare the noise properties with theoretical expectations. All of the QLP light curves are available at MAST as a High Level Science Product (HLSP) via doi:10.17909/t9-r086-e880 (https://archive.stsci.edu/hlsp/qlp). This is the largest collection of TESS photometry available to the public to date.

Keywords: space telescopes; transit photometry; astronomy data analysis
Recovery and Validation of Venus Neutral Atmospheric Profiles from Pioneer Venus Orbiter Radio Occultation Observations

The Pioneer Venus Orbiter radio occultation experiment acquired vertical profiles of neutral atmospheric temperature in the ionosphere of Venus. These profiles were not readily accessible to researchers. Here we report the recovery and validation of a set of neutral atmospheric temperature profiles from Pioneer Venus Orbiter. More than 40 profiles spanning many latitudes and local solar times were deemed acceptable for scientific analysis. These temperature profiles are consistent with temperature profiles measured by the four Pioneer Venus entry probes. The profiles are publicly available and ready for use in scientific investigations of the neutral atmosphere of Venus and related topics.

Keywords: venus
A New Broadening Technique of the Numerically Unresolved Solar Transition Region and Its Effect on the Spectroscopic Synthesis Using Coronal Approximation

The transition region is a thin layer of the solar atmosphere that controls the energy loss from the solar corona. Large numbers of grid points are required to resolve this thin transition region fully in numerical modeling. In this study, we propose a new numerical treatment, called LTRAC, which can be easily extended to the multidimensional domains. We have tested the proposed method using a one-dimensional hydrodynamic model of a coronal loop in an active region. The LTRAC method enables modeling of the transition region with a numerical grid size of 50-100 km, which is about 1000 times larger than the physically required value. We used the velocity differential emission measure to evaluate the possible effects on the optically thin emission. Lower-temperature emissions were better reproduced by the LTRAC method than by previous methods. Doppler shift and nonthermal width of the synthesized line emission agree with those from a high-resolution reference simulation within an error of several kilometers per second above the formation temperature of 105 K.

Keywords: solar transition region; solar corona; hydrodynamical simulations
Gravitational Wave Eigenfrequencies from Neutrino-driven Core-collapse Supernovae

Core-collapse supernovae (CCSNe) are predicted to produce gravitational waves (GWs) that may be detectable by Advanced LIGO/Virgo. These GW signals carry information from the heart of these cataclysmic events, where matter reaches nuclear densities. Recent studies have shown that it may be possible to infer the properties of the proto-neutron star (PNS) via GWs generated by hydrodynamic perturbations of the PNS. However, we lack a comprehensive understanding of how these relationships may change with the properties of CCSNe. In this work, we build a self-consistent suite of over 1000 exploding CCSNe from a grid of progenitor masses and metallicities combined with six different nuclear equations of state (EOS). Performing a linear perturbation analysis on each model, we compute the resonant GW frequencies of the PNS, and we motivate a time-agnostic method for identifying characteristic frequencies of the dominant GW emission. From this, we identify two characteristic frequencies, of the early- and late-time signal, that measure the surface gravity of the cold remnant neutron star, and simultaneously constrain the hot nuclear EOS. However, we find that the details of the CCSN model, such as the treatment of gravity or the neutrino transport, and whether it explodes, noticeably change the magnitude and evolution of the PNS eigenfrequencies.

Keywords: gravitational waves; core-collapse supernovae; gravitational wave sources; neutron stars; ligo; general relativity
GOALS-JWST: Tracing AGN Feedback on the Star-forming Interstellar Medium in NGC 7469

We present James Webb Space Telescope (JWST) Mid-Infrared Instrument (MIRI) integral-field spectroscopy of the nearby merging, luminous infrared galaxy, NGC 7469. This galaxy hosts a Seyfert type-1.5 nucleus, a highly ionized outflow, and a bright, circumnuclear star-forming ring, making it an ideal target to study active galactic nucleus (AGN) feedback in the local universe. We take advantage of the high spatial/spectral resolution of JWST/MIRI to isolate the star-forming regions surrounding the central active nucleus and study the properties of the dust and warm molecular gas on ~100 pc scales. The starburst ring exhibits prominent polycyclic aromatic hydrocarbon (PAH) emission, with grain sizes and ionization states varying by only ~30%, and a total star formation rate of 10-30 M ⊙ yr-1 derived from fine structure and recombination emission lines. Using pure rotational lines of H2 we detect 1.2 × 107 M ⊙ of warm molecular gas at a temperature higher than 200 K in the ring. All PAH bands get significantly weaker toward the central source, where larger and possibly more ionized grains dominate the emission, likely the result of the ionizing radiation and/or the fast wind emerging from the AGN. The small grains and warm molecular gas in the bright regions of the ring however display properties consistent with normal star-forming regions. These observations highlight the power of JWST to probe the inner regions of dusty, rapidly evolving galaxies for signatures of feedback and inform models that seek to explain the coevolution of supermassive black holes and their hosts.

Keywords: seyfert galaxies; active galactic nuclei; polycyclic aromatic hydrocarbons; starburst galaxies; luminous infrared galaxies
Benzoic Acid as the Preferred Precursor for the Chlorobenzene Detected on Mars: Insights from the Unique Cumberland Analog Investigation

The Cumberland drill sample from the Sheepbed mudstone in Gale Crater, Mars, revealed the first evidence of an indigenous Martian organic molecule, chlorobenzene, with the Sample Analysis at Mars (SAM) instrument on Curiosity. We created in the laboratory a mineralogical analog of the Cumberland sample (CBA) to aid in the understanding of the precursor organic molecule(s) that led to the detection of chlorobenzene. The CBA was analyzed by visible/near-infrared spectrometry, and the results are in accordance with Mastcam multispectral and the Chemical Camera passive analyses of Cumberland on Mars, demonstrating that the CBA is a relevant analog. CBA aliquots were spiked with 0.5 wt. % of benzoic acid and 1-2 wt. % of magnesium perchlorate and were run in SAM Testbed (TB). The TB evolved gas analysis (EGA) showed similarities with the Cumberland EGA on Mars in terms of the major volatiles H2O, CO2, and O2. The TB gas chromatography mass spectrometry displayed the presence of chlorobenzene at 23-28 pmol and dichlorobenzene. CBA aliquots were also analyzed in the laboratory with SAM-like EGA and the results on the laboratory setup confirmed the generation of chlorobenzene by a reaction between the benzoic acid and the magnesium perchlorates. The case for benzoic acid as a potential precursor for the chlorobenzene detected in the Martian regolith is strengthened with this new supporting laboratory data from the CBA. The quantification of chlorobenzene in the TB led to prediction of organic precursor abundance on Mars of hundreds, if not thousands, of parts per millions by weight.

Keywords: astrobiology; planetary science; mars; pre-biotic astrochemistry
One Is the Loneliest Number: Multiplicity in Cool Dwarfs

Stars in multiple systems offer a unique opportunity to learn about stellar formation and evolution. As they settle down into stable configurations, multiple systems occur in a variety of hierarchies and a wide range of separations between the components. We examine 11 known and 11 newly discovered multiple systems including at least one M dwarf with the latest astrometric data from Gaia Early Data Release 3 (EDR3). We find that the individual components of systems at very wide separations are often multiple systems themselves.

Keywords: binary stars; close binary stars; late-type stars; visual binary stars; wide binary stars
The Stability Boundary of the Distant Scattered Disk

The distant scattered disk is a vast population of trans-Neptunian minor bodies that orbit the Sun on highly elongated, long-period orbits. The orbital stability of scattered-disk objects (SDOs) is primarily controlled by a single parameter-their perihelion distance. While the existence of a perihelion boundary that separates chaotic and regular motion of long-period orbits is well established through numerical experiments, its theoretical basis as well as its semimajor axis dependence remain poorly understood. In this work, we outline an analytical model for the dynamics of distant trans-Neptunian objects and show that the orbital architecture of the scattered disk is shaped by an infinite chain of exterior 2:j resonances with Neptune. The widths of these resonances increase as the perihelion distance approaches Neptune's semimajor axis, and their overlap drives chaotic motion. Within the context of this theoretical picture, we derive an analytic criterion for instability of long-period orbits, and demonstrate that rapid dynamical chaos ensues when the perihelion drops below a critical value, given by ${q}_{\mathrm{crit}}={a}_{{\rm{N}}}{\left(\mathrm{ln}(({24}^{2}/5)({m}_{{\rm{N}}}/{M}_{\odot }){\left(a/{a}_{{\rm{N}}}\right)}^{5/2})\right)}^{1/2}$ . This expression constitutes an analytic boundary between the "detached" and actively "scattering" subpopulations of distant trans-Neptunian minor bodies. Additionally, we find that within the stochastic layer, the Lyapunov time of SDOs approaches the orbital period, and show that the semimajor axis diffusion coefficient is approximated by ${{ \mathcal D }}_{a}\,\sim (8/(5\pi ))({m}_{{\rm{N}}}/{M}_{\odot })\sqrt{{ \mathcal G }{M}_{\odot }{a}_{{\rm{N}}}}\,\exp \left[-{\left(q/{a}_{{\rm{N}}}\right)}^{2}/2\right]$ . We confirm our results with direct N-body simulations and highlight the connections between scattered-disk dynamics and the Chirikov Standard Map. Implications of our results for the long-term evolution of minor bodies in the distant solar system are discussed.

Keywords: orbits; perturbation methods; scattered disk objects
Solar Coronal Magnetic Field Extrapolation from Synchronic Data with AI-generated Farside

Solar magnetic fields play a key role in understanding the nature of the coronal phenomena. Global coronal magnetic fields are usually extrapolated from photospheric fields, for which farside data is taken when it was at the frontside, about two weeks earlier. For the first time we have constructed the extrapolations of global magnetic fields using frontside and artificial intelligence (AI)-generated farside magnetic fields at a near-real time basis. We generate the farside magnetograms from three channel farside observations of Solar Terrestrial Relations Observatory (STEREO) Ahead (A) and Behind (B) by our deep learning model trained with frontside Solar Dynamics Observatory extreme ultraviolet images and magnetograms. For frontside testing data sets, we demonstrate that the generated magnetic field distributions are consistent with the real ones; not only active regions (ARs), but also quiet regions of the Sun. We make global magnetic field synchronic maps in which conventional farside data are replaced by farside ones generated by our model. The synchronic maps show much better not only the appearance of ARs but also the disappearance of others on the solar surface than before. We use these synchronized magnetic data to extrapolate the global coronal fields using Potential Field Source Surface (PFSS) model. We show that our results are much more consistent with coronal observations than those of the conventional method in view of solar active regions and coronal holes. We present several positive prospects of our new methodology for the study of solar corona, heliosphere, and space weather.

Keywords: solar magnetic fields; solar corona; convolutional neural networks; the sun; space weather; astronomical models
Comet 108P/Ciffreo: The Blob

Short-period comet 108P/Ciffreo is known for its peculiar double morphology, in which the nucleus is accompanied by a comoving, detached, diffuse "blob." We report new observations of 108P/Ciffreo taken with the Hubble Space Telescope and the Nordic Optical Telescope and use them to determine the cause of this unusual morphology. The separation and the longevity of the blob across several orbits together rule out the possibility of a single, slow-moving secondary object near the primary nucleus. We use a model of coma particle dynamics under the action of solar gravity and radiation pressure to show that the blob is an artifact of the turnaround of particles ejected sunward and repelled by sunlight. Numerical experiments limit the range of directions which can reproduce the morphology and explain why the comoving blob appearance is rare.

Keywords: comets; short period comets; comae
Prospects of Gravitational-wave Follow-up through a Wide-field Ultraviolet Satellite: A Dorado Case Study

The detection of gravitational waves from the binary neuron star merger GW170817 and electromagnetic counterparts GRB170817A and AT2017gfo kick-started the field of gravitational-wave multimessenger astronomy. The optically red to near-infrared emission ("red" component) of AT2017gfo was readily explained as produced by the decay of newly created nuclei produced by rapid neutron capture (a kilonova). However, the ultraviolet to optically blue emission ("blue" component) that was dominant at early times (up to 1.5 days) received no consensus regarding its driving physics. Among many explanations, two leading contenders are kilonova radiation from a lanthanide-poor ejecta component and shock interaction (cocoon emission). In this work, we simulate AT2017gfo-like light curves and perform a Bayesian analysis to study whether an ultraviolet satellite capable of rapid gravitational-wave follow-up, could distinguish between physical processes driving the early "blue" component. We find that ultraviolet data starting at 1.2 hr distinguishes the two early radiation models up to 160 Mpc, implying that an ultraviolet mission like Dorado would significantly contribute to insights into the driving emission physics of the postmerger system. While the same ultraviolet data and optical data starting at 12 hr have limited ability to constrain model parameters separately, the combination of the two unlocks tight constraints for all but one parameter of the kilonova model up to 160 Mpc. We further find that a Dorado-like ultraviolet satellite can distinguish the early radiation models up to at least 130 (60) Mpc if data collection starts within 3.2 (5.2) hr for AT2017gfo-like light curves.

Keywords: bayesian statistics; gravitational waves; model selection; neutron stars; nucleosynthesis; ultraviolet astronomy
Most-likely DCF Estimates of Magnetic Field Strength

The Davis–Chandrasekhar–Fermi (DCF) method is widely used to evaluate magnetic fields in star-forming regions. Yet it remains unclear how well DCF equations estimate the mean plane-of-the-sky field strength in a map region. To address this question, five DCF equations are applied to an idealized cloud map. Its polarization angles have a normal distribution with dispersion σ θ , and its density and velocity dispersion have negligible variation. Each DCF equation specifies a global field strength B DCF and a distribution of local DCF estimates. The "most-likely" DCF field strength B ml is the distribution mode, for which a correction factor β ml ≡ B ml/B DCF is calculated analytically. For each equation, β ml < 1, indicating that B DCF is a biased estimator of B ml. The values of β ml are β ml ≈ 0.7 when ${B}_{\mathrm{DCF}}\propto {\sigma }_{\theta }^{-1}$ due to turbulent excitation of Alfvénic MHD waves, and β ml ≈ 0.9 when ${B}_{\mathrm{DCF}}\propto {\sigma }_{\theta }^{-1/2}$ due to non-Alfvénic MHD waves. These statistical correction factors β ml have partial agreement with correction factors ${\beta }_{\mathrm{sim}}$ obtained from MHD simulations. The relative importance of the statistical correction is estimated by assuming that each simulation correction has both a statistical and a physical component. Then the standard, structure function, and original DCF equations appear most accurate because they require the least physical correction. Their relative physical correction factors are 0.1, 0.3, and 0.4 on a scale from 0 to 1. In contrast, the large-angle and parallel-δ B equations have physical correction factors 0.6 and 0.7. These results may be useful in selecting DCF equations, within model limitations.

Keywords: interstellar magnetic fields; star formation
The Pre-explosion Mass Distribution of Hydrogen-poor Superluminous Supernova Progenitors and New Evidence for a Mass-Spin Correlation

Despite indications that superluminous supernovae (SLSNe) originate from massive progenitors, the lack of a uniformly analyzed statistical sample has so far prevented a detailed view of the progenitor mass distribution. Here we present and analyze the pre-explosion mass distribution of hydrogen-poor SLSN progenitors as determined from uniformly modeled light curves of 62 events. We construct the distribution by summing the ejecta mass posteriors of each event, using magnetar light-curve models presented in our previous works (and using a nominal neutron star remnant mass). The resulting distribution spans 3.6-40 M⊙, with a sharp decline at lower masses, and is best fit by a broken power law described by ${dN}/d\mathrm{log}M\propto {M}^{-0.41\pm 0.06}$ at 3.6-8.6 M⊙ and $\propto {M}^{-1.26\pm 0.06}$ at 8.6-40 M⊙. We find that observational selection effects cannot account for the shape of the distribution. Relative to Type Ib/c SNe, the SLSN mass distribution extends to much larger masses and has a different power-law shape, likely indicating that the formation of a magnetar allows more massive stars to explode as some of the rotational energy accelerates the ejecta. Comparing the SLSN distribution with predictions from single and binary star evolution models, we find that binary models for a metallicity of Z ≲ 1/3 Z⊙ are best able to reproduce its broad shape, in agreement with the preference of SLSNe for low metallicity environments. Finally, we uncover a correlation between the pre-explosion mass and the magnetar initial spin period, where SLSNe with low masses have slower spins, a trend broadly consistent with the effects of angular momentum transport evident in models of rapidly rotating carbon-oxygen stars.

Keywords: type ic supernovae; core-collapse supernovae; supernovae
Electromagnetic Proton Beam Instabilities in the Inner Heliosphere: Energy Transfer Rate, Radial Distribution, and Effective Excitation

Differential flows among different ion species are often observed in the solar wind, and such ion differential flows can provide the free energy to drive Alfvén/ion cyclotron and fast-magnetosonic/whistler instabilities. Previous works mainly focused on ion beam instability under the parameters representative of the solar wind nearby 1 au. In this paper we further study proton beam instability using the radial models of the magnetic field and plasma parameters in the inner heliosphere. We explore a comprehensive distribution of proton beam instability as functions of the heliocentric distance and the beam speed. We also perform a detailed analysis of the energy transfer between unstable waves and particles and quantify how much the free energy of the proton beam flows into unstable waves and other kinds of particle species (i.e., proton core, alpha particle, and electron). This work clarifies that both parallel and perpendicular electric fields are responsible for the excitation of oblique Alfvén/ion cyclotron and oblique fast-magnetosonic/whistler instabilities. Moreover, this work proposes an effective growth length to estimate whether the instability is efficiently excited or not. It shows that oblique Alfvén/ion cyclotron instability, oblique fast-magnetosonic/whistler instability, and oblique Alfvén/ion beam instability can be efficiently driven by proton beams drifting at the speed ~600-1300 km s-1 in the solar atmosphere. In particular, oblique Alfvén/ion cyclotron waves driven in the solar atmosphere can be significantly damped therein, leading to solar corona heating. These results are helpful for understanding proton beam dynamics in the inner heliosphere and can be verified through in situ satellite measurements.

Keywords: solar wind; plasma physics; plasma astrophysics