Sazuna/UAT_keywords huggingface dataset:
Updated Reference Wavelengths for Si VII and Mg VII Lines in the 272-281 Å Range. New reference wavelengths for atomic transitions of Mg VII and Si VII in the 272-281 Å wavelength range are derived using measurements from the Extreme-ultraviolet Imaging Spectrometer (EIS) on board the Hinode spacecraft. Mg VII and Si VII are important ions for measuring plasma properties in the solar transition region at around 0.6 MK. The six Si VII wavelengths are 13-21 mÅ and 7-11 mÅ longer than the values in the NIST Atomic Spectra Database (ASD) and the compilations of B. Edlén, respectively. The four Mg VII wavelengths are shorter than the values in the ASD by 8-12 mÅ but show reasonable agreement with the Edlén values. The new wavelengths will lead to more accurate Doppler shift measurements from the EIS instrument and will be valuable for spectral disambiguation modeling for the upcoming Multi-Slit Solar Explorer mission.

Keywords: Solar atmosphere, Atomic data, Ultraviolet spectroscopy, Solar transition region
On the Contribution of Coronal Mass Ejections to the Heliospheric Magnetic Flux Budget on Different Time Scales. Coronal mass ejections (CMEs) contribute closed magnetic flux to the heliosphere while they are connected at both ends to the Sun and play a key role in adding magnetic flux to the heliosphere. Here, we discuss how the type of magnetic reconnection that opens CME field lines in the inner heliosphere, i.e., interchange (IC) and/or interplanetary (IP) reconnection, determines the length of time CMEs contribute to the heliospheric flux budget. This distinction has not been taken into account in past studies that estimate the CME flux opening timescale. We outline key criteria to aid in distinguishing IC reconnection from IP reconnection based on in situ spacecraft data and highlight these through two example events. Studying the manner in which CMEs reconnect and open in the inner heliosphere yields important insights not only into CMEs' role in the heliospheric flux budget but also the evolution of CME complexity, connectivity, and topology.

Keywords: Solar magnetic reconnection, Solar coronal mass ejections, Heliosphere
Improving Coronal Hole Detections and Open Flux Estimates. One systematic limitation of solar coronal hole (CH) detection at extreme ultraviolet (EUV) wavelengths is the obscuration of dark regions of the corona by brighter structures along the line of sight. Another problem arises when using CHs to compute the Sun's open magnetic flux, where surface measurements of the radial magnetic field, ${B}_{r}^{\odot }$ , are situated slightly below the effective height of coronal EUV emission. In this paper, we explore these two limitations utilizing a thermodynamic magnetohydrodynamic (MHD) model of the corona for Carrington rotation (CR) 2101, where we generate CH detections from EUV 193 Å images of the corona forward-modeled from the MHD solution, and where the modeled open field is known. We demonstrate a method to combine EUV images into a full Sun map that helps alleviate CH obscuration called the minimum intensity disk merge (MIDM). We also show the variation in measured open flux and CH area that is due to the effective height differences between EUV and ${B}_{r}^{\odot }$ measurements. We then apply the MIDM method to SDO/AIA 193 Å observations from CR 2101, and conduct an analogous analysis. In this case, the MIDM method uses time-varying images, the effects of which are discussed. We show that overall, the MIDM method and an appreciation of the effective height mismatch provide a useful new way to extract a broader view of CHs, especially near the poles. In turn, they enable improved estimates of the open magnetic flux, and help facilitate comparisons between models and observations.

Keywords: Astronomy software, Astronomy data analysis, Solar surface, Solar corona, Solar coronal holes
Orientations of Dark Matter Halos in FIRE-2 Milky Way-mass Galaxies. The shape and orientation of dark matter (DM) halos are sensitive to the microphysics of the DM particles, yet in many mass models, the symmetry axes of the Milky Way's DM halo are often assumed to be aligned with the symmetry axes of the stellar disk. This is well motivated for the inner DM halo, but not for the outer halo. We use zoomed-in cosmological baryonic simulations from the Latte suite of FIRE-2 Milky Way-mass galaxies to explore the evolution of the DM halo's orientation with radius and time, with or without a major merger with a Large Magellanic Cloud analog, and when varying the DM model. In three of the four cold DM halos we examine, the orientation of the halo minor axis diverges from the stellar disk vector by more than 20° beyond about 30 galactocentric kpc, reaching a maximum of 30°-90°, depending on the individual halo's formation history. In identical simulations using a model of self-interacting DM with σ = 1 cm2 g-1, the halo remains aligned with the stellar disk out to ~200-400 kpc. Interactions with massive satellites (M ≳ 4 × 1010 M ⊙ at pericenter; M ≳ 3.3 × 1010 M ⊙ at infall) affect the orientation of the halo significantly, aligning the halo's major axis with the satellite galaxy from the disk to the virial radius. The relative orientation of the halo and disk beyond 30 kpc is a potential diagnostic of self-interacting DM, if the effects of massive satellites can be accounted for.

Keywords: Milky Way dark matter halo, Galaxy dark matter halos, Disk galaxies, Computational methods, Dark matter, Galaxies
r-process Abundance Patterns in the Globular Cluster M92. Whereas light-element abundance variations are a hallmark of globular clusters, there is little evidence for variations in neutron-capture elements. A significant exception is M15, which shows a star-to-star dispersion in neutron-capture abundances of at least one order of magnitude. The literature contains evidence both for and against a neutron-capture dispersion in M92. We conducted an analysis of archival Keck/HIRES spectra of 35 stars in M92, 29 of which are giants, which we use exclusively for our conclusions. M92 conforms to the abundance variations typical of massive clusters. Like other globular clusters, its neutron-capture abundances were generated by the r-process. We confirm a star-to-star dispersion in r-process abundances. Unlike M15, the dispersion is limited to "first-generation" (low-Na, high-Mg) stars, and the dispersion is smaller for Sr, Y, and Zr than for Ba and the lanthanides. This is the first detection of a relation between light-element and neutron-capture abundances in a globular cluster. We propose that a source of the main r-process polluted the cluster shortly before or concurrently with the first generation of star formation. The heavier r-process abundances were inhomogeneously distributed while the first-generation stars were forming. The second-generation stars formed after several crossing times (~0.8 Myr); hence, the second generation shows no r-process dispersion. This scenario imposes a minimum temporal separation of 0.8 Myr between the first and second generations.

Keywords: Globular star clusters, Nucleosynthesis, Abundance ratios, R-process, Chemical abundances
A Search for X-Ray/UV Correlation in the Reflection-dominated Seyfert 1 Galaxy Markarian 1044. Correlated variability between coronal X-rays and disk optical/UV photons provides a very useful diagnostic of the interplay between the different regions around an active galactic nucleus (AGN) and how they interact. AGNs that reveal strong X-ray reflection in their spectra should normally exhibit optical/UV to X-ray correlation consistent with reprocessing-whereas the optical/UV emission lags behind the X-rays. While such correlated delay has been seen in some sources, it has been absent in others. Mrk 1044 is one such source that has been known to reveal strong X-ray reflection in its spectra. In our analysis of three long XMM-Newton and several Swift observations of the source, we found no strong evidence for correlation between its UV and X-ray lightcurves both on short and long timescales. Among other plausible causes for the nondetection, we posit that higher X-ray variability rather than UV and strong general relativistic effects close to the black hole may also be responsible. We also present results from the spectral analysis based on XMM-Newton and NuSTAR observations, which show the strong soft X-ray excess and iron Kα line in the 0.3-50 keV spectrum that can be described by relativistic reflection.

Keywords: X-ray active galactic nuclei, Seyfert galaxies, Active galactic nuclei, High energy astrophysics
Probing the Interplay between Jets, Winds, and Multi-phase Gas in 11 Radio-quiet PG Quasars: A uGMRT-VLA Study. We present polarization-sensitive images from the Karl G. Jansky Very Large Array (VLA) at 5 GHz of 11 radio-quiet PG quasars. Based on the radio morphology, spectral index, and polarization properties from the VLA study, coupled with the findings of our previous 685 MHz uGMRT data, we find the presence of low-power jets on subarcsecond and arcsecond scales in nine sources; some show signatures of bent jets. The origin of radio emission remains unclear in the remaining two sources. Of the 11 sources, linear polarization is detected in four of them with fractional polarization ranging between 2% and 21%. In PG 1229+204, the inferred B-field direction is parallel to the local kiloparsec-scale jet direction. The inferred B-fields are transverse to the weak southward extension in PG 0934+013. For PG 0050+124 and PG 0923+129, the relationship between the B-field structure and radio outflow direction remains unclear. Localized or small-scale jet-medium interactions can be inferred across the sample based on the VLA jet kinetic power arguments and polarization data. These may have the potential as a feedback mechanism. We find that the radio properties do not show strong correlations with the star formation, [O III] and CO quantities published in the literature. The lack of evidence of AGN feedback on the global galaxy properties could be due to the relative timescales of AGN activity and those over which any impact might be taking place.

Keywords: Radio continuum emission, Radio quiet quasars, Polarimetry
Latitudinal Propagation of Thermal Rossby Waves in Stellar Convection Zones. Using an analytic model, we derive the eigenfrequencies for thermal Rossby waves that are trapped radially and latitudinally in an isentropically stratified atmosphere. We ignore the star's curvature and work in an equatorial f-plane geometry. The propagation of inertial waves is found to be sensitive to the relative direction of the wavevector to the zonal direction. Prograde propagating thermal Rossby waves are naturally trapped in the radial direction for frequencies above a critical threshold, which depends on the angle of propagation. Below the threshold frequency, there exists a continuous spectrum of prograde and retrograde inertial waves that are untrapped in an isentropic atmosphere but can be trapped by gradients in the specific entropy density. Finally, we discuss the implications of these waves on recent observations of inertial oscillations in the Sun, as well as in numerical simulations.

Keywords: Stellar convective zones, Internal waves, Hydrodynamics, Helioseismology, Solar convective zone, Solar oscillations, Stellar oscillations, Stellar rotation, Asteroseismology, Polytropes
What Is the Nature of the HESS J1731-347 Compact Object?. Once further confirmed in future analyses, the radius and mass measurement of HESS J1731-347 with $M={0.77}_{-0.17}^{+0.20}\,{M}_{\odot }$ and $R={10.4}_{-0.78}^{+0.86}\,\mathrm{km}$ will be among the lightest and smallest compact objects ever detected. This raises many questions about its nature and opens up the window for different theories to explain such a measurement. In this article, we use the information from Doroshenko et al. on the mass, radius, and surface temperature together with the multimessenger observations of neutron stars to investigate the possibility that HESS J1731-347 is one of the lightest observed neutron star, a strange quark star, a hybrid star with an early deconfinement phase transition, or a dark matter-admixed neutron star. The nucleonic and quark matter are modeled within realistic equation of states (EOSs) with a self-consistent calculation of the pairing gaps in quark matter. By performing the joint analysis of the thermal evolution and mass-radius constraint, we find evidence that within a 1σ confidence level, HESS J1731-347 is consistent with the neutron star scenario with the soft EOS as well as with a strange and hybrid star with the early deconfinement phase transition with a strong quark pairing and neutron star admixed with dark matter.

Keywords: Neutron stars, Gravitational waves, Dark matter, Compact objects
Jupiter's Equatorial Quasi-quadrennial Oscillation Forced by Internal Thermal Forcing. Observations have shown that there exists downward propagation of alternating westward/eastward jets in Jupiter's equatorial stratosphere, with a quasi-period between 4 and 6 yr. This phenomenon is generally called the quasi-quadrennial oscillation (QQO). Here, we simulate the QQO by injecting isotropic small-scale thermal disturbances into a 3D general circulation model of Jupiter. It is found that the internal thermal disturbance is able to excite a wealth of waves that generate the equatorial QQO and multiple jet streams at the middle and high latitudes of both hemispheres. The dominant wave mode in generating the QQO-like oscillation is that with a zonal wavenumber of 10. The inhomogeneous evolution of potential vorticity favors the emergence of off-equatorial zonal jets. The off-equatorial jets migrate to the equator, strengthen the deep equatorial jets, and result in the prolonging of the QQO-like oscillations.

Keywords: Jupiter, Atmospheric circulation
New Insights in the Bubble Wall of NGC 3324: Intertwined Substructures and a Bipolar Morphology Uncovered by JWST. We report the discovery of intertwined/entangled substructures toward the bubble wall of NGC 3324 below a physical scale of 4500 au, which is the sharp edge/ionization front/elongated structure traced at the interface between the H II region and the molecular cloud. The sharp edge appears wavy in the Spitzer 3.6-8.0 μm images (resolution ~2″). Star formation signatures have mostly been traced on one side of the ionization front, which lies on the molecular cloud's boundary. The James Webb Space Telescope's (JWST) near- and mid-infrared images (resolution ~0.″07-0.″7) are employed to resolve the sharp edge, which has a curvature facing the exciting O-type stars. The elongated structures are associated with the 3.3 μm polycyclic aromatic hydrocarbon (PAH) emission, the 4.05 μm ionized emission, and the 4.693 μm H2 emission. However, the PAH-emitting structures are depicted between the other two. The H2 emission reveals numerous intertwined substructures that are not prominently traced in the 3.3 μm PAH emission. The separation between two substructures in the H2 emission is ~1.″1 or 2420 au. The intertwined substructures are traced in the spatial areas associated with the neutral to H2 transition zone, suggesting the origin of these structures by "thin-shell" instability. Furthermore, an arc-like feature traced in the Spitzer 3.6-8.0 μm images is investigated as a bipolar H II region (extent ~0.35 pc) at T  d  ~25-28 K using the JWST images. A massive-star candidate VPHAS-OB1 #03518 seems to be responsible for the bipolar H II region.

Keywords: Interstellar dust extinction, Pre-main sequence stars, Star formation, Interstellar clouds, Interstellar medium, H II regions
X-Ray Spectral Variations of Circinus X-1 Observed with NICER throughout an Entire Orbital Cycle. Circinus X-1 (Cir X-1) is a neutron star binary with an elliptical orbit of 16.6 days. The source is unique for its extreme youth, providing a key to understanding early binary evolution. However, its X-ray variability is too complex to reach a clear interpretation. We conducted the first high-cadence (every 4 hr, on average) observations covering one entire orbit using the NICER X-ray telescope. The X-ray flux behavior can be divided into stable, dip, and flaring phases. The X-ray spectra in all phases can be described by a common model consisting of a partially covered disk blackbody emission and the line features from a highly ionized photoionized plasma. The spectral change over the orbit is attributable to rapid changes of the partial covering medium in the line of sight and gradual changes of the disk blackbody emission. Emission lines of H- and He-like Mg, Si, S, and Fe are detected, most prominently in the dip phase. The Fe emission lines change to absorption in the course of the transition from the dip phase to the flaring phase. The estimated ionization degree indicates no significant changes, suggesting that the photoionized plasma is stable over the orbit. We propose a simple model in which the disk blackbody emission is partially blocked by a local medium in the line of sight that has spatial structures depending on the azimuth of the accretion disk. Emission lines upon the continuum emission are from the photoionized plasma located outside of the blocking material.

Keywords: X-ray binary stars, High energy astrophysics, Plasma astrophysics, Atomic spectroscopy, Ionization, Spectroscopy
ALMA Observations of Supernova Remnant N49 in the Large Magellanic Cloud. II. Non-LTE Analysis of Shock-heated Molecular Clouds. We present the first compelling evidence of shock-heated molecular clouds associated with the supernova remnant (SNR) N49 in the Large Magellanic Cloud (LMC). Using 12CO(J = 2-1, 3-2) and 13CO(J = 2-1) line emission data taken with the Atacama Large Millimeter/Submillimeter Array, we derived the H2 number density and kinetic temperature of eight 13CO-detected clouds using the large velocity gradient approximation at a resolution of 3.″5 (~0.8 pc at the LMC distance). The physical properties of the clouds are divided into two categories: three of them near the shock front show the highest temperatures of ~50 K with densities of ~500-700 cm-3, while other clouds slightly distant from the SNR have moderate temperatures of ~20 K with densities of ~800-1300 cm-3. The former clouds were heated by supernova shocks, but the latter were dominantly affected by the cosmic-ray heating. These findings are consistent with the efficient production of X-ray recombining plasma in N49 due to thermal conduction between the cold clouds and hot plasma. We also find that the gas pressure is roughly constant except for the three shock-engulfed clouds inside or on the SNR shell, suggesting that almost no clouds have evaporated within the short SNR age of ~4800 yr. This result is compatible with the shock-interaction model with dense and clumpy clouds inside a low-density wind bubble.

Keywords: Supernova remnants, X-ray sources, Molecular clouds, Interstellar medium
Solar Atmospheric Heating Due to Small-scale Events in an Emerging Flux Region. We investigate the thermal, kinematic, and magnetic structure of small-scale heating events in an emerging flux region (EFR). We use high-resolution multiline observations (including Ca II 8542 Å, Ca II K, and the Fe I 6301 Å line pair) of an EFR located close to the disk center from the CRISP and CHROMIS instruments at the Swedish 1 m Solar Telescope. We perform non-LTE inversions of multiple spectral lines to infer the temperature, velocity, and magnetic field structure of the heating events. Additionally, we use the data-driven Coronal Global Evolutionary Model to simulate the evolution of the 3D magnetic field configuration above the events and understand their dynamics. Furthermore, we analyze the differential emission measure to gain insights into the heating of the coronal plasma in the EFR. Our analysis reveals the presence of numerous small-scale heating events in the EFR, primarily located at polarity inversion lines of bipolar structures. These events not only heat the lower atmosphere but also significantly heat the corona. The data-driven simulations, along with the observed enhancement of currents and Poynting flux, suggest that magnetic reconnection in the lower atmosphere is likely responsible for the observed heating at these sites.

Keywords: Solar atmosphere, Spectropolarimetry, Solar chromospheric heating, Magnetic fields
NICER Observations of Thermonuclear Bursts from 4U 1728-34: Detection of Oscillations prior to the Onset of Two Bursts. We present temporal and time-resolved spectral analyses of all the thermonuclear X-ray bursts observed from the neutron star low-mass X-ray binary 4U 1728-34 with NICER from 2017 June to 2019 September. In total, we detected 11 X-ray bursts from the source and performed time-resolved spectroscopy. Unlike some of the earlier results for other bursting sources from NICER, our spectral results indicate that the use of a scaling factor for the persistent emission is not statistically necessary. This is primarily a result of the strong interstellar absorption in the line of sight toward 4U 1728-34, which causes the count rates to be significantly lower at low energies. We also searched for burst oscillations and detected modulations in six different bursts at around the previously known burst oscillation frequency of 363 Hz. Finally, we report the detection of oscillations prior to two bursts at 356 and 359 Hz, respectively. This is the first time in the literature where burst oscillations are detected before the rapid rise in X-ray flux, from any known burster. These oscillations disappear as soon as the burst starts to rise and occur at a somewhat lower frequency than the oscillations we detect during the bursts.

Keywords: Neutron stars, Low-mass x-ray binary stars, X-ray bursts
Observations of the Chromospheric Evershed Flow of Sunspot Penumbra with the Application of the Self-organizing Map Technique. The sunspot penumbra is usually observed in the photosphere and it is of particular interest for its magnetoconvection, which seems to transport the heat from the top of the convection zone into the solar atmosphere. It is well known that the penumbra magnetic field extends into the upper layers of the solar atmosphere forming the so-called superpenumbra. Thanks to the application of the Self-organizing Map technique to a spectral data set containing monochromatic images acquired along the Ca II 854.2 nm and Hα 656.28 nm lines, we were able to segment the penumbra and to measure the plasma velocity along the chromospheric portions of penumbral filaments. We found that the head, body, and tail of penumbral filaments show vertical flows compatible with the persistence of the Evershed flow. Instead, the inverse Evershed flow has been observed only in the outer portion of the superpenumbra. We found that two opposite Evershed regimes work next to each other, without overlapping, and both contribute to the downflow around sunspots. These results confirm the uncombed model of the sunspot penumbra and provide some hints that the downflow around sunspots may be ascribed to the magnetic field dragging the plasma down.

Keywords: Sunspots, Magnetohydrodynamics, Solar chromosphere, Solar photosphere