adsabs/SciX_UAT_keywords huggingface dataset:
Efficiently Jet-powered Radiation in Intermediate-luminosity Optical Transients

I show that a flow structure where wide jets hit a slower expanding shell might be very efficient in channeling the kinetic energy of the jets to radiation, therefore accounting for, at least a fraction of, intermediate-luminosity optical transients (ILOTs) where the total radiation energy is much larger than what recombination energy of the outflow can supply. This type of flow might occur in the frame of the high-accretion-powered ILOT (HAPI) model, where there is a high mass accretion rate as a result of stellar merger or mass transfer in a binary system. I derive the condition on the jets half opening angle for the jets not to penetrate through the slow shell, as well as the ratio of the photon diffusion time to expansion time. This ratio cannot be too large if a large fraction of the thermal energy is channeled to radiation. I apply the jet-powered radiation model to the Great Eruption of Eta Carinae, to V838 Mon, and to V4332 Sgr, and find a plausible set of parameters for these ILOTs. I expect the jet-powered radiation model to be more efficient in converting kinetic energy to radiation than ILOT models that are based on equatorial mass concentration. In many cases, though, I expect both jets and equatorial mass concentration to occur in the same system.

Keywords: variable stars; stellar jets; luminous blue variable stars; close binary stars; eruptive variable stars
Solar Calibration of the Convective Mixing Length for Use with the ÆSOPUS Opacities in MESA

The simplistic but ubiquitous Mixing Length Theory (MLT) formalism is used to model convective energy transport within 1D stellar evolution calculations. The formalism relies on the free parameter α MLT, which must be independently calibrated within each stellar evolution program and for any given set of physical assumptions. We present a solar calibration of α MLT appropriate for use with the ÆSOPUS opacities, which have recently been made available for use with the MESA stellar evolution software. We report a calibrated value of α MLT = 1.931 and demonstrate the impact of using an appropriately calibrated value in simulations of a 3M ⊙ asymptotic giant branch star.

Keywords: stellar evolutionary models; stellar convective zones; stellar atmospheric opacity
INTEGRAL Limits on Past High-energy Activity from FRB 20200120E in M81

The repeating fast radio burst FRB 20200120E is located in a globular cluster belonging to the nearby M81 galaxy. Its small distance (3.6 Mpc) and accurate localization make it an interesting target to search for bursting activity at high energies. From 2003 November to 2021 September, the INTEGRAL satellite has obtained an exposure time of 18 Ms on the M81 sky region. We used these data to search for hard X-ray bursts from FRB 20200120E using the IBIS/ISGRI instrument, without finding any significant candidate, down to an average fluence limit of ~10-8 erg cm-2 (20-200 keV). The corresponding limit on the isotropic luminosity for a burst of duration Δt is $\sim {10}^{45}\left(\tfrac{10\,\mathrm{ms}}{{\rm{\Delta }}t}\right)$ erg s-1, the deepest limit obtained for an extragalactic FRB in the hard X-ray range. This rules out the emission of powerful flares at a rate higher than 0.1 yr-1 that could be expected in models invoking young hyperactive magnetars.

Keywords: magnetars; radio bursts
Distance and Mass of the NGC 253 Galaxy Group

Two dwarf galaxies, WOC2017-07 and PGC 704814, located in the vicinity of the nearby luminous spiral galaxy NGC 253 were observed with the Advanced Camera for Surveys on the Hubble Space Telescope. Their distances of 3.62 ± 0.18 Mpc and 3.66 ± 0.18 Mpc were derived using the tip of the red giant branch method. These distances are consistent with the dwarf galaxies being members of the NGC 253 group. Based on the radial velocities and projected separations of seven assumed dwarf companions, we estimated the total mass of NGC 253 to be (8.1 ± 2.6)1011M⊙, giving a total-mass-to-K-luminosity ratio of Morb/LK = (8.5 ± 2.7)M⊙/L⊙. A notable property of NGC 253 is its declined rotation curve. NGC 253 joins four other luminous spiral galaxies in the Local Volume with declined rotation curves (NGC 2683, NGC 2903, NGC 3521, and NGC 5055) that together have the low average total-mass-to-luminosity ratio, Morb/LK = (5.5 ± 1.1)M⊙/L⊙. This value is only ∼1/5 of the corresponding ratio for the Milky Way and M31.

Keywords: galaxy distances; galaxy groups; dwarf galaxies; hertzsprung russell diagram
Timing Six Energetic Rotation-powered X-Ray Pulsars, Including the Fast-spinning Young PSR J0058-7218 and Big Glitcher PSR J0537-6910

Measuring a pulsar's rotational evolution is crucial to understanding the nature of the pulsar. Here, we provide updated timing models for the rotational evolution of six pulsars, five of which are rotation phase-connected using primarily NICER X-ray data. For the newly discovered fast energetic young pulsar, PSR J0058-7218, we increase the baseline of its timing model from 1.4 days to 8 months and not only measure more precisely its spin-down rate $\dot{\nu }=(-6.2324\pm 0.0001)\times {10}^{-11}\,\mathrm{Hz}\,{{\rm{s}}}^{-1}$ but also for the first time the second time derivative of its spin rate $\ddot{\nu }=(4.2\pm 0.2)\times {10}^{-21}\,\mathrm{Hz}\,{{\rm{s}}}^{-2}$ . For the fastest and most energetic young pulsar, PSR J0537-6910 (with a 16 ms spin period), we detect four more glitches, for a total of 15 glitches over 4.5 yr of NICER monitoring, and show that its spin-down behavior continues to set this pulsar apart from all others, including a long-term braking index n = -1.234 ± 0.009 and interglitch braking indices that asymptote to ≲7 for long times after a glitch. For PSR J1101-6101, we measure a much more accurate spin-down rate that agrees with a previous value measured without phase connection. For PSR J1412+7922 (also known as Calvera), we extend the baseline of its timing model from our previous 1 yr model to 4.4 yr, and for PSR J1849-0001, we extend the baseline from 1.5 to 4.7 yr. We also present a long-term timing model of the energetic pulsar PSR J1813-1749, by fitting previous radio and X-ray spin frequencies from 2009-2019 and new ones measured here using 2018 NuSTAR and 2021 Chandra data.

Keywords: neutron stars; pulsars; rotation powered pulsars; x-ray sources; ephemerides
The ALMA View of Positive Black Hole Feedback in the Dwarf Galaxy Henize 2–10

Henize 2–10 is a dwarf starburst galaxy hosting a ∼106 M ⊙ black hole (BH) that is driving an ionized outflow and triggering star formation within the central ∼100 pc of the galaxy. Here, we present Atacama Large Millimeter/submillimeter Array continuum observations from 99 to 340 GHz, as well as spectral line observations of the molecules CO (1–0, 3–2), HCN (1–0, 3–2), and HCO+ (1–0, 3–2), with a focus on the BH and its vicinity. Incorporating centimeter-wave radio measurements from the literature, we show that the spectral energy distribution of the BH is dominated by synchrotron emission from 1.4 to 340 GHz, with a spectral index of α ≈ ‑ 0.5. We analyze the spectral line data and identify an elongated molecular gas structure around the BH with a velocity distinct from the surrounding regions. The physical extent of this molecular gas structure is ≈130 pc × 30 pc and the molecular gas mass is ∼106 M ⊙. Despite an abundance of molecular gas in this general region, the position of the BH is significantly offset from the peak intensity, which may explain why the BH is radiating at a very low Eddington ratio. Our analysis of the spatially resolved line ratio between CO J = 3–2 and J = 1–0 implies that the CO gas in the vicinity of the BH is highly excited, particularly at the interface between the BH outflow and the regions of triggered star formation. This suggests that the cold molecular gas is being shocked by the bipolar outflow from the BH, supporting the case for positive BH feedback.

Keywords: interstellar medium; dwarf galaxies; active galaxies
Bridging Optical and Far-infrared Emission-line Diagrams of Galaxies from Local to the Epoch of Reionization: Characteristic High [O III] 88 μm/SFR at z > 6

We present photoionization modeling of galaxy populations at z ∼ 0, 2, and >6 to bridge optical and far-infrared (FIR) emission-line diagrams. We collect galaxies with measurements of optical and/or FIR ([O III] 88 μm and [C II] 158 μm) emission-line fluxes and plot them on the [O III]λ5007/Hβ-[N II]λ6585/Hα (BPT) and L([O III]88)/SFR-L([C II]158)/SFR diagrams, where SFR is the star formation rate and L([O III]88) and L([C II]158) are the FIR line luminosities. We aim to explain the galaxy distributions on the two diagrams with photoionization models that employ three nebular parameters: the ionization parameter U, hydrogen density nH, and gaseous metallicity Zgas. Our models successfully reproduce the nebular parameters of local galaxies, and then predict the distributions of the z ∼ 0, 2, and >6 galaxies in the diagrams. The predicted distributions illustrate the redshift evolution on all the diagrams; e.g., [O III]/Hβ and [O III]88/[C II]158 ratios continuously decrease from z > 6 to 0. Specifically, the z > 6 galaxies exhibit ∼0.5 dex higher U than low-redshift galaxies at a given Zgas and show predicted flat distributions on the BPT diagram at log[O III]/Hβ = 0.5-0.8. We find that some of the z > 6 galaxies exhibit high L([O III]88)/SFR ratios. To explain these high ratios, our photoionization models require a low stellar-to-gaseous-metallicity ratio or bursty/increasing star formation history at z > 6. JWST will test the predictions and scenarios for the z > 6 galaxies proposed by our photoionization modeling.

Keywords: galaxy evolution; high-redshift galaxies; h ii regions; photodissociation regions; optical astronomy; far infrared astronomy
A New Method of Reconstructing Galactic 3D Structures Using Ultralong-wavelength Radio Observations

The free-free absorption of low-frequency radio waves by thermal electrons in the warm ionized medium of our Galaxy becomes very significant at ≲10 MHz (ultralong wavelength), and the absorption strength depends on the radio frequency. Upcoming space experiments such as the Discovering Sky at the Longest Wavelength and Farside Array for Radio Science Investigations of the Dark Ages and Exoplanets will produce high-resolution multifrequency sky maps at the ultralong wavelength, providing a new window to observe the universe. In this Paper we propose that from these ultralong-wavelength multifrequency maps, the 3D distribution of the Galactic electrons can be reconstructed. This novel and robust reconstruction of the Galactic electron distribution will be a key science case of those space missions. Ultralong-wavelength observations will be a powerful tool for studying the astrophysics relevant to the Galactic electron distribution, for example, the impacts of supernova explosions on electron distribution, and the interaction between interstellar atoms and ionizing photons escaped from the H II regions around massive stars.

Keywords: interstellar medium; interstellar plasma; interstellar absorption; milky way galaxy; radio interferometers
The Magnetic Field Environment of Active Region 12673 That Produced the Energetic Particle Events of September 2017

Forecasting solar energetic particles (SEPs), and identifying flares/coronal mass ejections (CMEs) from active regions (ARs) that will produce SEP events in advance is extremely challenging. We investigate the magnetic field environment of AR 12673, including the AR's magnetic configuration, the surrounding field configuration in the vicinity of the AR, the decay index profile, and the footpoints of the Earth-connected magnetic field, around the time of four eruptive events. Two of the eruptive events are SEP productive (2017 September 4 at 20:00 UT and September 6 at 11:56 UT), while two are not (September 4 at 18:05 UT and September 7 at 14:33 UT). We analyzed a range of EUV and white-light coronagraph observations along with potential field extrapolations and find that the CMEs associated with the SEP-productive events either trigger null point reconnection that redirects flare-accelerated particles from the flare site to the Earth-connected field and/or have a significant expansion (and shock formation) into the open Earth-connected field. The rate of change of the decay index with height indicates that the region could produce a fast CME (v > 1500 km s-1), which it did during events 2 and 3. The AR's magnetic field environment, including locations of open magnetic field and null points along with the magnetic field connectivity and propagation direction of the CMEs play an important role in the escape and arrival of SEPs at Earth. Other SEP-productive ARs should be investigated to determine whether their magnetic field environment and CME propagation direction are significant in the escape and arrival of SEPs at Earth.

Keywords: solar activity; solar energetic particles; solar magnetic fields; solar magnetic reconnection; solar flares; solar coronal mass ejections
JWST's TEMPLATES for Star Formation: The First Resolved Gas-phase Metallicity Maps of Dust-obscured Star-forming Galaxies at z ∼ 4

We present the first spatially resolved maps of gas-phase metallicity for two dust-obscured star-forming galaxies at z ~ 4, from the JWST TEMPLATES Early Release Science program, derived from NIRSpec integral field unit spectroscopy of the Hα and [N II] emission lines. Empirical optical line calibrations are used to determine that the sources are globally enriched to near-solar levels. While one source shows elevated [N II]/Hα ratios and broad Hα emission consistent with the presence of an active galactic nucleus in a ≳1 kpc region, we argue that both systems have already undergone significant metal enrichment as a result of their extremely high star formation rates. Utilizing Atacama Large Millimeter/submillimeter Array rest-frame 380 μm continuum and [CI](3P2-3P1) line maps we compare the spatial variation of the metallicity and gas-to-dust ratio in the two galaxies, finding the two properties to be anticorrelated on highly resolved spatial scales, consistent with various literature studies of z ~ 0 galaxies. The data are indicative of the enormous potential of JWST to probe the enrichment of the interstellar medium on ~kpc scales in extremely dust-obscured systems at z ~ 4 and beyond.

Keywords: galaxy evolution; high-redshift galaxies; galaxy formation; starburst galaxies; strong gravitational lensing
Plasma-beta Modulated Characteristics of Magnetohydrodynamic Waves around the Heliospheric Current Sheet

The magnetohydrodynamics (MHD) wave modes in the heliospheric current sheet (HCS) and the associated heliospheric plasma sheet (HPS) have not been comprehensively investigated in the literature. Based on a frequency-related identification approach, the properties of MHD waves are investigated during 154 HCS crossings observed by the Wind spacecraft from 1995 to 2013. Statistically, the incidence of MHD waves around HCS/HPS is found to be modulated by the plasma β within the HPS: (1) β > 5, both Alfvén and slow waves obviously decay within the HPS, with the occurrence rate (OR) decreasing from 60% and 20% in the upstream/downstream to 41% and 14% in the HPS vicinity, respectively; (2) 1 < β ≤ 5, the OR of Alfvén waves (AWs) remains nearly stable. However, more slow waves are generated after the HCS crossing, with OR increasing from 13% in the upstream/downstream to 22%; (3) β ≤ 1, the OR of Alfvén and slow waves remains at ∼58% and 20% during the entire crossing, in spite of some irregular fluctuations. The results for the HCS without a clear HPS are similar to the situations of a low β HPS. The parametric decay instability of AWs is proposed as being responsible for the more slow waves generated in the moderate β HPS, and some indirect observational clues are also given.

Keywords: solar wind; interplanetary magnetic fields; interplanetary physics; magnetohydrodynamics; alfven waves
Component of Energy Flow from Supercritical Accretion Disks Around Rotating Stellar Mass Black Holes

By performing two-dimensional axisymmetric general relativistic radiation magnetohydrodynamics simulations with spin parameter a* varying from -0.9 to 0.9, we investigate the dependence on the black hole spin of the energy flow from a supercritical accretion disk around a stellar mass black hole. It is found that optically and geometrically thick disks form near the equatorial plane, and a part of the disk matter is launched from the disk surface in all models. The gas ejection is mainly driven by the radiative force, but magnetic force cannot be neglected when ∣a*∣ is large. The energy outflow efficiency (total luminosity normalized by ${\dot{M}}_{\mathrm{in}}{c}^{2};$ ${\dot{M}}_{\mathrm{in}}$ and c are the mass-accretion rate at the event horizon and the light speed) is higher for rotating black holes than for nonrotating black holes. This is 0.7% for a* = -0.7, 0.3% for a* = 0, and 5% for a* = 0.7 for ${\dot{M}}_{\mathrm{in}}\sim 100{L}_{\mathrm{Edd}}/{c}^{2}$ (L Edd is the Eddington luminosity). Furthermore, although the energy is mainly released by radiation when a* ~ 0, the Poynting power increases with ∣a*∣ and exceeds the radiative luminosity for models with a* ≥ 0.5 and a* ≤ -0.7. The faster the black hole rotates, the higher the power ratio of the kinetic luminosity to the isotropic luminosity tends to be. This implies that objects with a high (low) power ratio may have rapidly (slowly) rotating black holes. Among ultraluminous X-ray sources, IC342 X-1, is a candidate with a rapidly rotating black hole.

Keywords: black hole physics; high energy astrophysics; kerr black holes; active galactic nuclei; x-ray binary stars; tidal disruption; accretion; radiative magnetohydrodynamics; general relativity; magnetohydrodynamical simulations; hydrodynamical simulations
The Metallicity Dependence of the High-mass X-Ray Binary Luminosity Function

In this work, we present detailed constraints on the metallicity dependence of the high-mass X-ray binary (HMXB) X-ray luminosity function (XLF). We analyze ≈5 Ms of Chandra data for 55 actively star-forming galaxies at D ≲ 30 Mpc, with gas-phase metallicities spanning $12+\mathrm{log}({\rm{O}}/{\rm{H}})$ ≈ 7-9.2. Within the galactic footprints, our sample contains a total of 1311 X-ray point sources, of which ≈49% are expected to be HMXBs, with the remaining sources likely to be low-mass X-ray binaries (LMXBs; ≈22%) and unrelated background sources (≈29%). We construct a model that successfully characterizes the average HMXB XLF over the full metallicity range. We demonstrate that the SFR-normalized HMXB XLF shows clear trends with metallicity, showing steadily increasing numbers of luminous and ultraluminous X-ray sources ( $\mathrm{log}L$ (erg s-1) = 38-40.5) with declining metallicity. However, we find that the low-luminosity ( $\mathrm{log}L$ (erg s-1) = 36-38) HMXB XLF appears to show a nearly constant SFR scaling and slope with metallicity. Our model provides a revised scaling relation of integrated LX/SFR versus $12+\mathrm{log}({\rm{O}}/{\rm{H}})$ , and a new characterization of its SFR-dependent stochastic scatter. The general trend of this relation is broadly consistent with past studies based on integrated galaxy emission; however, our model suggests that this relation is driven primarily by the high-luminosity end of the HMXB XLF. Our results have implications for binary population synthesis models, the nature of super-Eddington accreting objects (e.g., ultraluminous X-ray sources), recent efforts to identify active galactic nucleus candidates in dwarf galaxies, and the X-ray radiation fields in the early universe during the epoch of cosmic heating at z ≳ 10.

Keywords: high mass x-ray binary stars; metallicity; star formation; spiral galaxies; x-ray binary stars; x-ray astronomy; compact objects
Gravity-dominated Collisions: A Model for the Largest Remnant Masses with Treatment for "Hit and Run" and Density Stratification

We develop empirical relationships for the accretion and erosion of colliding gravity-dominated bodies of various compositions under conditions expected in late-stage solar system formation. These are fast, easily coded relationships based on a large database of smoothed particle hydrodynamics (SPH) simulations of collisions between bodies of different compositions, including those that are water rich. The accuracy of these relations is also comparable to the deviations of results between different SPH codes and initial thermal/rotational conditions. We illustrate the paucity of disruptive collisions between major bodies, as compared to collisions between less massive planetesimals in late-stage planet formation, and thus focus on more probable, low-velocity collisions, though our relations remain relevant to disruptive collisions as well. We also pay particular attention to the transition zone between merging collisions and those where the impactor does not merge with the target, but continues downrange, a "hit-and-run" collision. We find that hit-and-run collisions likely occur more often in density-stratified bodies and across a wider range of impact angles than suggested by the most commonly used analytic approximation. We also identify a possible transitional zone in gravity-dominated collisions where larger bodies may undergo more disruptive collisions when the impact velocity exceeds the sound speed, though understanding this transition warrants further study. Our results are contrary to the commonly assumed invariance of total mass (scale), density structure, and material composition on the largest remnants of giant impacts. We provide an algorithm for adopting our model into N-body planet formation simulations, so that the mass of growing planets and debris can be tracked.

Keywords: impact phenomena; planetary science; planet formation; hydrodynamics; hydrodynamical simulations; solar system terrestrial planets
New Roads to the Small-scale Universe: Measurements of the Clustering of Matter with the High-redshift UV Galaxy Luminosity Function

The epochs of cosmic dawn and reionization present promising avenues for understanding the role of dark matter (DM) in our cosmos. The first galaxies that populated the universe during these eras resided in DM halos that were much less massive than their counterparts today. Consequently, observations of such galaxies can provide us with a handle on the clustering of DM in an otherwise currently inaccessible regime. In this work, we use high-redshift UV galaxy luminosity function (UV LF) data from the Hubble Space Telescope to study the clustering properties of DM at small scales. In particular, we present new measurements of the matter power spectrum at wavenumbers 0.5 Mpc-1 < k < 10 Mpc-1 to roughly 30% precision, obtained after marginalizing over the unknown astrophysics. These new data points cover the uncharted redshift range 4 ≤ z ≤ 10 and encompass scales beyond those probed by cosmic microwave background and large-scale structure observations. This work establishes the UV LF as a powerful tool to probe the nature of DM in a different regime than other cosmological and astrophysical data sets.

Keywords: cosmology