Sazuna/UAT_keywords huggingface dataset:
High-resolution SOFIA/EXES Spectroscopy of Water Absorption Lines in the Massive Young Binary W3 IRS 5. We present in this paper mid-infrared (5-8 μm) spectroscopy toward the massive young binary W3 IRS 5, using the Echelon Cross Echelle Spectrograph (EXES) spectrometer in high-resolution mode (R ~ 50,000) from the NASA Stratospheric Observatory for Infrared Astronomy (SOFIA). Many (~180) ν 2 = 1-0 and (~90) ν 2 = 2-1 absorption rovibrational transitions are identified. Two hot components over 500 K and one warm component of 190 K are identified through Gaussian fittings and rotation diagram analysis. Each component is linked to a CO component identified in the IRTF/iSHELL observations (R = 88,100) through their kinematic and temperature characteristics. Revealed by the large scatter in the rotation diagram, opacity effects are important, and we adopt two curve-of-growth analyses, resulting in column densities of ~1019 cm-2. In one analysis, the model assumes a foreground slab. The other assumes a circumstellar disk with an outward-decreasing temperature in the vertical direction. The disk model is favored because fewer geometry constraints are needed, although this model faces challenges as the internal heating source is unknown. We discuss the chemical abundances along the line of sight based on the CO-to-H2O connection. In the hot gas, all oxygen not locked in CO resides in water. In the cold gas, we observe a substantial shortfall of oxygen and suggest that the potential carrier could be organics in solid ice.

Keywords: Interstellar molecules, Star formation, Infrared spectroscopy, Infrared sources
Properties of Star Formation of the Large Magellanic Cloud As Probed by Young Stellar Objects. We perform a systematic study of the evolutionary stages and stellar masses of young stellar objects (YSOs) in the Large Magellanic Cloud (LMC) to investigate the properties of star formation in the galaxy. There are 4825 sources in our YSO sample, which are constructed by combining the previous studies identifying YSOs in the LMC. Spectral energy distributions of the YSOs from optical to infrared wavelengths were fitted with a model consisting of stellar, polycyclic aromatic hydrocarbon, and dust emissions. We utilize the stellar-to-dust luminosity ratios thus derived to study the evolutionary stages of the sources; younger YSOs are expected to show lower stellar-to-dust luminosity ratios. We find that most of the YSOs are associated with the interstellar gas across the galaxy, which are younger with more gas, suggesting that more recent star formation is associated with larger amounts of the interstellar medium (ISM). N157 shows a hint of higher stellar-to-dust luminosity ratios between active star-forming regions in the LMC, suggesting that recent star formation in N157 is possibly in later evolutionary stages. We also find that the stellar mass function tends to be bottom-heavy in supergiant shells (SGSs), indicating that gas compression by SGSs may be ineffective in compressing the ISM enough to trigger massive star formation. There is no significant difference in the stellar mass function between YSOs likely associated with the interface between colliding SGSs and those with a single SGS, suggesting that gas compression by collisions between SGSs may also be ineffective for massive star formation.

Keywords: Young stellar objects, Star formation, Large Magellanic Cloud
Tianwen-1 and MAVEN Observations of the Response of Mars to an Interplanetary Coronal Mass Ejection. Interplanetary coronal mass ejections (ICMEs) are solar transients that have significant effects on the upper atmosphere and ionosphere of Mars. The simultaneous spacecraft observations from Tianwen-1/MOMAG in solar wind and multiple instruments on board the Mars Atmosphere and Volatile Evolution (MAVEN) in the Martian upper atmosphere are used to study the response of Mars to an ICME. The ICME was observed at Mars by Tianwen-1 and MAVEN at 00:00 UT on 2021 December 10, which was earlier observed by BepiColombo upstream of Mars at 22:32 UT on 2021 December 6. During 2021 December 6-15, MAVEN measured the nightside ionosphere and Tianwen-1 measured the dayside ionosphere while both were inside the Martian bow shock. The rapid drop in densities of ionospheric ions and electrons, which is typically identified as the end of the ionosphere at altitudes between 300-800 km, is known as the ionopause. The altitude of the Martian ionopause location was lowered by the high dynamic pressure of the solar wind during the ICME passage. The depletion of the plasma density in the topside Martian ionosphere on the nightside reveals the presence of substantial ion and electron escape to space through the interaction between the ICME and Mars. The column abundance of plasma dramatically decreased, with 34% e-, 61% ${{\rm{O}}}_{2}^{+}$ , and 73% O+ reduced. This study highlights the significant impact of the space weather associated with the intense magnetic field and high dynamic pressure of the ICME on Mars's atmosphere, which is particularly important for future human exploration missions to Mars.

Keywords: Solar system terrestrial planets, Solar coronal mass ejections
Climatological Gravity Waves in the Middle and Upper Atmosphere of Mars Based on ACS/TGO Observations. Gravity waves (GWs) are important for the vertical coupling of the Martian atmosphere. The middle atmosphere is the key region where GWs propagate to the upper thermosphere and generate momentum and energy exchange, but the knowledge of middle-atmosphere GWs is incomplete, due to the lack of observations with the kilometer-scale resolution. We have analyzed the climatology of GW activity in the middle and upper atmosphere of Mars using 20-180 km temperature profiles measured by the Atmospheric Chemistry Suite instrument on board the Trace Gas Orbiter. The results show that the amplitudes of GWs extracted in this study are generally less than 15% and that the centers of the strongest GW activity vary significantly with the seasons. Second, the strongest GW activity in the mesosphere indicates the strong dissipation effects of the mesopause, and the mid-atmospheric GWs show a seasonal pattern that is stronger in the winter hemisphere. During the global dust event of MY34, the enhancement of GWs in the middle atmosphere is most pronounced at low and middle latitudes where the dust storms are active. It is possible that changes in the temperature structure of the middle atmosphere adjust the atmospheric circulation and thus improve the propagation of GWs. Furthermore, GW activity is stronger on the dayside than on the nightside, and there is no significant correlation between amplitudes and background temperature. This suggests a limited role of convective instability in limiting the growth of GWs in the middle atmosphere, with nonlinear damping competing with that of molecular diffusion at different harmonics.

Keywords: Internal waves, Mars, Mesosphere
Interstellar Conditions Deduced from Interstellar Neutral Helium Observed by IBEX and Global Heliosphere Modeling. In situ observations of interstellar neutral (ISN) helium atoms by the IBEX-Lo instrument on board the Interstellar Boundary Explorer (IBEX) mission are used to determine the velocity and temperature of the pristine very local interstellar medium (VLISM). Most ISN helium atoms penetrating the heliosphere, known as the primary population, originate in the pristine VLISM. As the primary atoms travel through the outer heliosheath, they charge exchange with He+ ions in slowed and compressed plasma, creating the secondary population. With more than 2.4 million ISN helium atoms being sampled by IBEX during ISN seasons 2009-2020, we compare the observations with the predictions of a parameterized model of ISN helium transport in the heliosphere. We account for the filtration of ISN helium atoms at the heliospheric boundaries by charge-exchange and elastic collisions. We examine the sensitivity of the ISN helium fluxes to the interstellar conditions described by the pristine VLISM velocity, temperature, magnetic field, and composition. We show that comprehensive modeling of the filtration processes is critical for interpreting ISN helium observations, as the change in the derived VLISM conditions exceeds the statistical uncertainties when accounting for these effects. The pristine VLISM parameters found by this analysis are the flow speed (26.6 km s-1), inflow direction in ecliptic coordinates (255.°7, 5.°04), temperature (7350 K), and B - V plane inclination to the ecliptic plane (53.°7). The derived pristine VLISM He+ density is 9.7 × 10-3 cm-3. Additionally, we show a strong correlation between the interstellar plasma density and magnetic field strength deduced from these observations.

Keywords: Astrosphere interstellar medium interactions, Interstellar atomic gas, Charge transfer, Heliosphere, Collision physics, Heliosheath, Interstellar medium wind
Event Rate of Fast Radio Bursts from Binary Neutron Star Mergers. It is proposed that a one-off fast radio burst (FRB) with periodic structure may be produced during the inspiral phase of a binary neutron star (BNS) merger. In this paper, we study the event rate of such kind of FRB. We first investigate the properties of two one-off FRBs with periodic structure (i.e., FRB 20191221A and FRB 20210213A) in this scenario, by assuming a fast magnetosonic wave is responsible for their radio emission. For the luminosities and periods of these bursts, it is found that for the NSs in the premerger BNS, magnetic field strengths of B ≳ 1012 G are required. This is relatively high compared with those of most of the BNSs observed in our Galaxy, of which their magnetic fields are around 109 G. Since the observed BNSs in our Galaxy are binaries that have not suffered a merger, a credible event rate of BNS-merger-originated FRBs should be estimated by considering the evolution of both the BNS systems and their magnetic fields. Based on population synthesis and adopting decaying magnetic fields of the NSs, we estimate the event rate of BNS mergers relative to their final magnetic fields. We find that rapidly merging BNSs tend to merge with high magnetization, and the event rate of BNS-merger-originated FRBs, i.e., BNS mergers with both NSs' magnetic fields being higher than 1012 G, is ~8 × 104 yr-1 (19% of all BNS mergers) for redshifts z &lt; 1.

Keywords: Close binary stars, Neutron stars, Magnetic fields, Radio transient sources
The Accretion Mode in Sub-Eddington Supermassive Black Holes: Getting into the Central Parsecs of Andromeda. The inner kiloparsec regions surrounding sub-Eddington (luminosity less than 10-3 in Eddington units, L Edd) supermassive black holes (BHs) often show a characteristic network of dust filaments that terminate in a nuclear spiral in the central parsecs. Here we study the role and fate of these filaments in one of the least accreting BHs known, M31 (10-7 L Edd) using hydrodynamical simulations. The evolution of a streamer of gas particles moving under the barred potential of M31 is followed from kiloparsec distance to the central parsecs. After an exploratory study of initial conditions, a compelling fit to the observed dust/ionized gas morphologies and line-of-sight velocities in the inner hundreds of parsecs is produced. After several million years of streamer evolution, during which friction, thermal dissipation, and self-collisions have taken place, the gas settles into a disk tens of parsecs wide. This is fed by numerous filaments that arise from an outer circumnuclear ring and spiral toward the center. The final configuration is tightly constrained by a critical input mass in the streamer of several 103 M ☉ (at an injection rate of 10-4 ${M}_{\odot }\,{{\rm{yr}}}^{-1}$ ); values above or below this lead to filament fragmentation or dispersion respectively, which are not observed. The creation of a hot gas atmosphere in the region of ~106 K is key to the development of a nuclear spiral during the simulation. The final inflow rate at 1 pc from the center is ~1.7 × 10-7 M ☉ yr-1, consistent with the quiescent state of the M31 BH.

Keywords: Supermassive black holes, Hydrodynamical simulations, Interstellar filaments, Interstellar medium, Andromeda Galaxy, Astronomical simulations
MESSENGER Observations of Multiple Magnetic Energy Releases during Mercury's Substorm. Substorms are energy storage and dissipation processes that occur in planetary magnetospheres accompanied by numerous phenomena, such as magnetic dipolarizations, plasma sheet thinning and thickening, magnetic flux ropes, and plasmoid ejections. Recent MESSENGER observations have revealed substorm activity in Mercury's near magnetotail, with average durations of 2-3 minutes for both the growth and expansion phases. Herein, we report MESSENGER spacecraft observations of sporadic and short-term energy dissipation processes during the substorm expansion phase in Mercury's magnetotail. Three magnetic dipolarizations lasting for ~4 minutes were detected during the expansion phase and manifested as step-like enhancements in the northward component of the magnetic field. The magnetic field strength decreased during each dipolarization, indicating an intermittent release of magnetic energy. They arise owing to multiple magnetic pileup effects caused by planetward bursty bulk flows ejected from distant magnetotail reconnections. Additionally, in close proximity to each dipolarization, we observed the occurrence of pulse-like fluctuations in the B  y component. These new MESSENGER observations suggest that during the expansion phase of Mercury's substorm, the energy dissipation can be caused by multiple local transient processes, although the duration is much shorter than that of Earth.

Keywords: Space plasmas, Solar magnetic reconnection, Plasma physics, Mercury (planet), Planetary magnetospheres, Magnetic fields
Study of Jupiter's Interior with Quadratic Monte Carlo Simulations. We construct models for Jupiter's interior that match the gravity data obtained by the Juno and Galileo spacecraft. To generate ensembles of models, we introduce a novel quadratic Monte Carlo technique, which is more efficient in confining fitness landscapes than the affine invariant method that relies on linear stretch moves. We compare how long it takes the ensembles of walkers in both methods to travel to the most relevant parameter region. Once there, we compare the autocorrelation time and error bars of the two methods. For a ring potential and the 2d Rosenbrock function, we find that our quadratic Monte Carlo technique is significantly more efficient. Furthermore, we modified the walk moves by adding a scaling factor. We provide the source code and examples so that this method can be applied elsewhere. Here we employ our method to generate five-layer models for Jupiter's interior that include winds and a prominent dilute core, which allows us to match the planet's even and odd gravity harmonics. We compare predictions from the different model ensembles and analyze how much an increase in the temperature at 1 bar and ad hoc change to the equation of state affect the inferred amount of heavy elements in the atmosphere and in the planet overall.

Keywords: Markov chain Monte Carlo, Jupiter
O, Ne, Mg, and Fe Abundances in Hot X-Ray-emitting Halos of Galaxy Clusters, Groups, and Giant Early-type Galaxies with XMM-Newton RGS Spectroscopy. Chemical elements in the hot medium permeating early-type galaxies, groups, and clusters make such objects an excellent laboratory for studying metal enrichment and cycling processes on the largest scales of the universe. Here, we report the analysis by the XMM-Newton Reflection Grating Spectrometer of 14 early-type galaxies, including the well-known brightest cluster galaxies of Perseus, for instance. The spatial distribution of the O/Fe, Ne/Fe, and Mg/Fe ratios is generally flat in the central 60″ regions of each object, irrespective of whether or not a central Fe abundance drop has been reported. Common profiles between noble gas and normal metal suggest that the dust depletion process does not work predominantly in these systems. Therefore, observed abundance drops are possibly attributed to other origins, such as systematics in the atomic codes. Giant systems with a high ratio of gas mass to luminosity tend to hold a hot gas (~2 keV) yielding the solar N/Fe, O/Fe, Ne/Fe, Mg/Fe, and Ni/Fe ratios. Contrarily, light systems in a sub-keV temperature regime, including isolated or group-centered galaxies, generally exhibit supersolar N/Fe, Ni/Fe, Ne/O, and Mg/O ratios. We find that the latest supernova nucleosynthesis models fail to reproduce such a supersolar abundance pattern. Possible systematic uncertainties contributing to these high abundance ratios of cool objects are also discussed in tandem with the crucial role of future X-ray missions.

Keywords: Galaxy clusters, Chemical abundances, Astrochemistry, Chemical enrichment, Galaxy groups, Interstellar medium, Intergalactic medium, Intracluster medium, Early-type galaxies
The Magnetic Fields of Starburst Galaxies. I. Identification and Characterization of the Thermal Polarization in the Galactic Disk and Outflow. Far-infrared polarized emission by means of magnetically aligned dust grains is an excellent tracer of the magnetic fields (B-fields) in the cold phase of the galactic outflows of starburst galaxies. We present a comprehensive study of the B-fields in three nearby (3.5-17.2 Mpc) starbursts (M82, NGC 253, and NGC 2146) at 5 pc-1.5 kpc resolutions using publicly available 53-890 μm imaging polarimetric observations with Stratospheric Observatory for Infrared Astronomy/HAWC+, James Clerk Maxwell Telescope/POL-2, and ALMA. We find that the polarized spectral energy distributions (SEDs) of the full galaxies are dominated by the polarized SEDs of the outflows with dust temperatures of ${T}_{{\rm{d}},\mathrm{outflow}}^{\mathrm{PI}}\sim 45$ K and an emissive index of ${\beta }_{\mathrm{outflow}}^{\mathrm{PI}}\sim 2.3$ . The disks are characterized by low ${T}_{{\rm{d}},\mathrm{disk}}^{\mathrm{PI}}=[24,31]$ K and ${\beta }_{\mathrm{disk}}^{\mathrm{PI}}\sim 1$ . We show that disk- and outflow-dominated galaxies can be better distinguished by using polarized SEDs instead of total SEDs. We compute the 53-850 μm polarization spectrum of the disk and outflow, and find that dust models of the diffuse ISM can reproduce the fairly constant polarization spectrum of the disk, &lt; P disk&gt; = 1.2% ± 0.5%. The dust models of heterogenous clouds and two-temperature components are required to explain the polarization spectrum of the outflow (2%-4% at 53 μm, ~1% at 850 μm, and a minimum within 89-154 μm). We conclude that the polarized dust grains in the outflow arise from a dust population with higher dust temperature and emissivities than those from the total flux. The B-fields of the outflows have maximum extensions within 89-214 μm reaching heights of ~4 kpc, and have flatter polarized fluxes than total fluxes. The extension of the B-field permeating the circumgalactic medium increases as the star formation rate increases.

Keywords: Interstellar dust, Starburst galaxies, Far infrared astronomy, Interstellar magnetic fields, Galaxy winds, Polarimetry, Extragalactic magnetic fields
Obtaining the Strength of the Magnetic Field from E- and B-Modes of Dust Polarization. We perform numerical simulations of supersonic magnetohydrodynamic (MHD) turbulence and calculate Fourier power spectra of E- and B-modes arising from dust polarization. We pay close attention to the ratio of E-mode to B-mode spectra (a.k.a. E/B power asymmetry) on small spatial scales. We find that the ratio depends on the strength of the mean magnetic field: the stronger the mean magnetic field, the smaller the ratio. More precisely speaking, the ratio scales with the Alfvén Mach number M  A , the rms velocity divided by the Alfvén speed of the mean magnetic field, when it lies in the range 1 ≲ M  A  ≲ 30. This result implies that we can use the E/B power asymmetry to constrain the strength of the mean magnetic field in supersonic and super-Alfvénic MHD turbulence.

Keywords: Interstellar dust, Interstellar magnetic fields, Polarimetry, Interplanetary turbulence
The Effects of Self-interacting Bosonic Dark Matter on Neutron Star Properties. We propose a model of asymmetric bosonic dark matter (DM) with self-repulsion. By adopting the two-fluid formalism, we study different DM distribution regimes, either, fully condensed inside the core of a star, or, otherwise, distributed in a dilute halo around a neutron star (NS). We show that for a given total gravitational mass, DM condensed in a core leads to a smaller radius and tidal deformability compared to a pure baryonic star. This effect may be interpreted as an effective softening of the equation of state. On the other hand, the presence of a DM halo increases the tidal deformability and total gravitational mass. As a result, an accumulated DM inside compact stars could mimic an apparent softening/stiffening of strongly interacting matter EoS and constraints we impose on it at high densities. We limit the model parameter space by confronting the cross section of the DM self-interaction to the constraint extracted from the analysis of the Bullet Cluster. Furthermore, from the analysis of the effect of DM particles, interaction strength, and relative DM fractions inside NSs we obtained a rigorous constraint on model parameters. To identify its impact on NSs we consider the DM fraction may reach up to 5%, which could be considered too high in several scenarios. Finally, we discuss several pieces of smoking gun evidence of the presence of DM that is free from the abovementioned degeneracy between the effect of DM and properties of strongly interacting matter. These signals could be probed with future and ongoing astrophysical and gravitational wave surveys.

Keywords: Neutron stars, Gravitational waves, Dark matter
Turbulent Diffusion of the Particles within Pulsar Wind Nebulae. A turbulent diffusion model is presented to account for the energy and spatial diffusion of the particles within pulsar wind nebulae (PWNe), with the assumption that the energy injected from the pulsar into the nebula is split between the turbulence waves and electrons/positrons. In the model, the mutual interactions between the turbulence waves and particles are taken into account, representing the damping effect of the turbulence waves and the stochastic acceleration and spatial diffusion of the particles, respectively. The evolutions of the turbulence waves and particles are described with the coupled kinetic equations, in which the Kolmogorov- and Kraichnan-type turbulence are, respectively, considered. The model is applied to the Crab Nebula and shows that the spectral energy distribution of the PWN can be naturally explained. Our modeling results indicate that, for the Crab Nebula, the stochastic acceleration and spatial diffusion processes play a role in modifying the electron spectrum at the low energies of E e ≲ 1 TeV. The damping process seems more effective for modulating the turbulent spectrum in the Kraichnan-type turbulence, resulting in the nonlinear variations of the current energy and spatial diffusion coefficients with energy generated in the wave-particle systems. In the Kolmogorov-type turbulence, the diffusion coefficients are more consistent with the quasi-linear distributions, due to the energy cascade dominating over the damping effect.

Keywords: Supernova remnants, Pulsar wind nebulae, Pulsars