Sazuna/UAT_keywords huggingface dataset:
Formation and Dynamics in an Observed Preeruptive Filament. The formation of filaments/prominences is still a debated topic. Many different processes have been proposed: levitation, injection of cool plasma, merging filaments, and cooling plasma in hot loops. We take the opportunity to make a multiwavelength analysis of the formation of an active-region filament, combining several UV and EUV observations including the new Ne VII 465 Å filtergrams provided by the Solar Upper Transition Region Imager on board the Space Advanced Technology satellite. The filament is mainly observed at the limb for 3 hr. It is progressively formed through a series of stages, including emergence and cooling of hot loops, reconnection between small filaments, material transfer in a large filament channel, and reconnection between filaments and emerged hot loops. From the observations at 465 Å, we find that the new-formed filaments show bright structures as in 304 Å, while the long-lived stable filaments display dark morphology as in 211 Å. This suggests that the plasma around 0.5 MK would be an essential component of new-formed filaments and the material temperature in filaments would be variable during their evolution. The filament formed by the recombination of two filaments and an emerged hot loop finally erupts. After reconnection, the final filament shows a highly twisted structure of both bright and dark strands, which is surrounded by several weak and dispersive looplike structures. This eruptive filament has a complex multichannel topology and covers a wide range of temperatures.

Keywords: Solar active regions, Solar magnetic reconnection, Solar extreme ultraviolet emission, Solar active region filaments
Spectroscopy from Photometry: A Population of Extreme Emission Line Galaxies at 1.7 ≲ z ≲ 6.7 Selected with JWST Medium Band Filters. We use JWST/NIRCam medium band photometry in a single pointing of the Canadian NIRISS Unbiased Cluster Survey to identify 118 extreme emission-line galaxies (EELGs) over 1.7 ≲ z ≲ 6.7, selected using a set of color cuts that target galaxies with extreme [O III] + Hβ and Hα emission. We show that our medium band color selections are able to select galaxies based on emission-line EW, which is advantageous to more commonly used selections since it does not require strong continuum emission, and can select galaxies with faint or red continuum fluxes. The median EWs of our sample is EW(Hα) = 893 Å and EW ([O III] + Hβ) = 1255 Å and includes some objects with EW ([O III] + Hβ) ~ 3000 Å. These systems are mostly compact with low stellar mass (median $\mathrm{log}({M}_{\star }/{M}_{\odot })=8.03$ ), low metallicity (median Z = 0.14 Z ⊙), little dust (median A  V  = 0.18 mag), and high SSFR (median SSFR = 1.18 × 10-8 yr-1). Additionally, galaxies in our sample show increasing EW(Hα) and EW([O III] + Hβ) with redshift, an anticorrelation of EW(Hα) with stellar mass, and no correlation between EW([O III] + Hβ) and stellar mass. Finally, we present NIRSpec spectroscopy of 15 of the EELGs in our sample. These spectra confirm the redshifts and EWs of the EELGs calculated from the medium bands, which demonstrates the accuracy and efficiency of our color selections. Overall, we show that there are significant advantages to using medium band photometry to identify and study EELGs at a wide range of redshifts.

Keywords: Starburst galaxies, James Webb Space Telescope, High-redshift galaxies, Emission line galaxies
The Importance of the Upper Atmosphere to CO/O<SUB>2</SUB> Runaway on Habitable Planets Orbiting Low-mass Stars. Efforts to spectrally characterize the atmospheric compositions of temperate terrestrial exoplanets orbiting M dwarf stars with JWST are now underway. Key molecular targets of such searches include O2 and CO, which are potential indicators of life. Recently, it was proposed that CO2 photolysis generates abundant (≳0.1 bar) abiotic O2 and CO in the atmospheres of habitable M dwarf planets with CO2-rich atmospheres, constituting a strong false positive for O2 as a biosignature and further complicating efforts to use CO as a diagnostic of surface biology. Importantly, this implied that TRAPPIST-1e and TRAPPIST-1f, now under observation with JWST, would abiotically accumulate abundant O2 and CO, if habitable. Here, we use a multi-model approach to reexamine photochemical O2 and CO accumulation on planets orbiting M dwarf stars. We show that photochemical O2 remains a trace gas on habitable CO2-rich M dwarf planets, with earlier predictions of abundant O2 and CO due to an atmospheric model top that was too low to accurately resolve the unusually high CO2 photolysis peak on such worlds. Our work strengthens the case for O2 as a biosignature gas, and affirms the importance of CO as a diagnostic of photochemical O2 production. However, observationally relevant false-positive potential remains, especially for O2's photochemical product O3, and further work is required to confidently understand O2 and O3 as biosignature gases on M dwarf planets.

Keywords: Extrasolar rocky planets, Exoplanet atmospheric composition , M dwarf stars, Theoretical models, Biosignatures, Habitable planets
Discovery of X-Ray Polarization from the Black Hole Transient Swift J1727.8-1613. We report the first detection of the X-ray polarization of the bright transient Swift J1727.8-1613 with the Imaging X-ray Polarimetry Explorer. The observation was performed at the beginning of the 2023 discovery outburst, when the source resided in the bright hard state. We find a time- and energy-averaged polarization degree of 4.1% ± 0.2% and a polarization angle of 2.°2 ± 1.°3 (errors at 68% confidence level; this translates to ~20σ significance of the polarization detection). This finding suggests that the hot corona emitting the bulk of the detected X-rays is elongated, rather than spherical. The X-ray polarization angle is consistent with that found in submillimeter wavelengths. Since the submillimeter polarization was found to be aligned with the jet direction in other X-ray binaries, this indicates that the corona is elongated orthogonal to the jet.

Keywords: Accretion, X-ray astronomy, Low-mass x-ray binary stars, Polarimetry, Astrophysical black holes
PSR J2150+3427: A Possible Double Neutron Star System. PSR J2150+3427 is a 0.654 s pulsar discovered by the Commensal Radio Astronomy FAST Survey. From the follow-up observations, we find that the pulsar is in a highly eccentric orbit (e = 0.601) with an orbital period of 10.592 days and a projected semimajor axis of 25.488 lt-s. Using 2.7 yr of timing data, we also measured the rate of periastron advance  ω̇  = 0.0115(4) deg yr‑1. An estimate for the total mass of the system using the  ω̇  gives M tot = 2.59(13)M ⊙, which is consistent with most of the known double neutron star (DNS) systems and one neutron star (NS)–white dwarf (WD) system named B2303+46. Combining  ω̇  with the mass function of the system gives the masses of M  p  &lt; 1.67 and M  c  &gt; 0.98 M ⊙ for the pulsar and the companion star, respectively. This constraint, along with the spin period and orbital parameters, suggests that it is possibly a DNS system, and we cannot entirely rule out the possibility of an NS–WD system. Future timing observations will vastly improve the uncertainty in  ω̇ , and are likely to allow the detection of additional relativistic effects, which can be used to modify the values of M  p  and M  c . With a spin-down luminosity of  Ė  = 5.07(6) × 1029 erg s‑1, PSR J2150+3427 is a very low-luminosity pulsar, with only the binary pulsar J2208+4610 having a smaller  Ė .

Keywords: Radio pulsars, Neutron stars, Binary pulsars, Pulsars
A Wide Metallicity Range for Gyr-old Stars in the Nuclear Star Cluster. We report metallicities for three ~Gyr-old stars in the Milky Way nuclear star cluster (NSC) using high-resolution near-infrared spectroscopy. We derive effective temperatures from a calibration with Sc line strength, which yields results in good agreement with other methods, and metallicities from spectral fits to Fe I lines. Our derived metallicities range from -1.2 &lt; [Fe/H] &lt; + 0.5, a span of 1.7 dex. In addition we use isochrone projection to obtain masses of 1.6-4.3 M ⊙, and ages assuming single-star evolution. The oldest of these stars is 1.5 Gyr while the youngest and most metal-rich is only 100 Myr. The wide range in metallicity poses interesting questions concerning the chemical evolution and enrichment of the NSC and adds to the evidence for the presence of a young, metal-rich population in the NSC. We suggest that the candidate intermediate-age, metal-poor ([Fe/H] = -1.2) star may be best explained as a blue straggler from an underlying old population.

Keywords: Stellar abundances, Galactic center, Early-type stars
Constraints on the Persistent Radio Source Associated with FRB 20190520B Using the European VLBI Network. We present very long baseline interferometry (VLBI) observations of a continuum radio source potentially associated with the fast radio burst source FRB 20190520B. Using the European VLBI network, we find the source to be compact on VLBI scales with an angular size of &lt;2.3 mas (3σ). This corresponds to a transverse physical size of &lt;9 pc (at the z = 0.241 redshift of the host galaxy), confirming it to be as fast radio burst (FRB) persistent radio source (PRS) like that associated with the first-known repeater FRB 20121102A. The PRS has a flux density of 201 ± 34 μJy at 1.7 GHz and a spectral radio luminosity of L 1.7 GHz = (3.0 ± 0.5) × 1029 erg s-1 Hz-1 (also similar to the FRB 20121102A PRS). Compared to previous lower-resolution observations, we find that no flux is resolved out on milliarcsecond scales. We have refined the PRS position, improving its precision by an order of magnitude compared to previous results. We also report the detection of the FRB 20190520B burst at 1.4 GHz and find the burst position to be consistent with the PRS position, at ≲20 mas. This strongly supports their direct physical association and the hypothesis that a single central engine powers both the bursts and the PRS. We discuss the model of a magnetar in a wind nebula and present an allowed parameter space for its age and the radius of the putative nebula powering the observed PRS emission. Alternatively, we find that an accretion-powered hypernebula model also fits our observational constraints.

Keywords: Very long baseline interferometry, Dwarf galaxies, Astrometry, Radio continuum emission, Radio transient sources
The Aligned Orbit of the Eccentric Proto Hot Jupiter TOI-3362b. High-eccentricity tidal migration predicts the existence of highly eccentric proto hot Jupiters on the "tidal circularization track," meaning that they might eventually become hot Jupiters, but that their migratory journey remains incomplete. Having experienced moderate amounts of tidal evolution of their orbital elements, proto hot Jupiter systems can be powerful test beds for the underlying mechanisms of eccentricity growth. Notably, they may be used for discriminating between variants of high-eccentricity migration, each predicting a distinct evolution of misalignment between the star and the planet's orbit. We constrain the spin-orbit misalignment of the proto hot Jupiter TOI-3362b with high-precision radial-velocity observations using ESPRESSO at Very Large Telescope. The observations reveal a sky-projected obliquity $\lambda ={1.2}_{-2.7}^{+2.8}$ ° and constrain the orbital eccentricity to e = 0.720 ± 0.016, making it one of the most eccentric gas giants for which the obliquity has been measured. Although the large eccentricity and the striking orbit alignment of the planet are puzzling, we suggest that ongoing coplanar high-eccentricity migration driven by a distant companion is a possible explanation for the system's architecture. This distant companion would need to reside beyond 5 au at 95% confidence to be compatible with the available radial-velocity observations. *Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under program ID 110.23Y8.004.

Keywords: Exoplanet dynamics, Exoplanet migration, Hot Jupiters, Exoplanets, Planetary alignment
Tidal Dissipation Regimes among the Short-period Exoplanets. The efficiency of tidal dissipation provides a zeroth-order link to a planet's physical properties. For super-Earth and sub-Neptune planets in the range R ⊕ ≲ R  p  ≲ 4R ⊕, particularly efficient dissipation (i.e., low tidal quality factors) may signify terrestrial-like planets capable of maintaining rigid crustal features. Here, we explore global constraints on planetary tidal quality factors using a population of planets in multiple-planet systems whose orbital and physical properties indicate susceptibility to capture into secular spin-orbit resonances. Planets participating in secular spin-orbit resonance can maintain large axial tilts and significantly enhanced heating from obliquity tides. When obliquity tides are sufficiently strong, planets in low-order mean-motion resonances can experience resonant repulsion (period ratio increase). The observed distribution of period ratios among transiting planet pairs may thus depend nontrivially on the underlying planetary structures. We model the action of resonant repulsion and demonstrate that the observed distribution of period ratios near the 2:1 and 3:2 commensurabilities implies Q values spanning from Q ≈ 101-107 and peaking at Q ≈ 106. This range includes the expected range in which super-Earth and sub-Neptune planets dissipate (Q ≈ 103-104). This work serves as a proof of concept for a method of assessing the presence of two dissipation regimes, and we estimate the number of additional multitransiting planetary systems needed to place any bimodality in the distribution on a strong statistical footing.

Keywords: Exoplanet structure, Exoplanet tides, Exoplanet dynamics
Rapid Evolution of the White Dwarf Pulsar AR Scorpii. Analysis of AR Sco optical light curves spanning 9 yr shows a secular change in the relative amplitudes of the beat pulse pairs generated by the two magnetic poles of its rotating white dwarf. Recent photometry now shows that the primary and secondary beat pulses have similar amplitudes, while in 2015 the primary pulse was approximately twice that of the secondary peak. The equalization in the beat pulse amplitudes is also seen in the linearly polarized flux. This rapid evolution is consistent with precession of the white dwarf spin axis. The observations imply that the pulse amplitudes cycle over a period of ≳40 yr but that the upper limit is currently poorly constrained. If precession is the mechanism driving the evolution, then over the next 10 yr the ratio of the beat pulse amplitudes will reach a maximum followed by a return to asymmetric beat pulses.

Keywords: Rotation powered pulsars, White dwarf stars, DQ Herculis stars, Cataclysmic variable stars, Magnetic poles
Black Hole Mergers Driven by a Captured Low-mass Companion. Increased eccentricity of a black hole binary leads to reduced merger times. With n-body simulations and analytic approximations including the effects of general relativity (GR), we show that even a low-mass companion orbiting a black hole binary can cause significant eccentricity oscillations of the binary as a result of the Kozai-Lidov mechanism. A companion with a mass as low as about 1% of the binary mass can drive the binary eccentricity up to ≳0.8, while a mass of a few percent can drive eccentricities greater than 0.98. For low-mass companions, this mechanism requires the companion to be on an orbit that is closer to retrograde than to prograde to the binary orbit, and this may occur through capture of the third body. The effects of GR limit the radial range for the companion for which this mechanism works for the closest binaries. The merger timescale may be reduced by several orders of magnitude for a captured companion mass of only a few percent of the binary mass.

Keywords: Stellar dynamics, Black holes
Constraining the Properties of Black Hole Seeds from the Farthest Quasars. Over 60 yr after the discovery of the first quasar, more than 275 such sources are identified in the epoch of reionization at z &gt; 6. JWST is now exploring higher redshifts (z ≳ 8) and lower-mass (≲107 M ⊙) ranges. The discovery of progressively farther quasars is instrumental to constraining the properties of the first population of black holes (BHs), or BH seeds, formed at z ~ 20-30. For the first time, we use Bayesian analysis of the most comprehensive catalog of quasars at z &gt; 6 to constrain the distribution of BH seeds. We show that the mass distribution of BH seeds can be effectively described by combining a power law and a lognormal function tailored to the mass ranges associated with light and heavy seeds, assuming Eddington-limited growth and early seeding time. Our analysis reveals a power-law slope of $-{0.70}_{-0.46}^{+0.46}$ and a lognormal mean of ${4.44}_{-0.30}^{+0.30}$ . The inferred values of the Eddington ratio, the duty cycle, and the mean radiative efficiency are ${0.82}_{-0.10}^{+0.10}$ , ${0.66}_{-0.23}^{+0.23}$ , and ${0.06}_{-0.02}^{+0.02}$ , respectively. Models that solely incorporate a power law or a lognormal distribution within the specific mass range corresponding to light and heavy seeds are statistically strongly disfavored, unlike models not restricted to this specific range. Our results suggest that including both components is necessary to comprehensively account for the masses of high-redshift quasars, and that both light and heavy seeds formed in the early Universe and grew to form the population of quasars we observe.

Keywords: Early universe, Bayesian statistics, Quasars, Active galaxies, Galaxy evolution
The Magnesium Isotope Composition of Samples Returned from Asteroid Ryugu. The nucleosynthetic isotope composition of planetary materials provides a record of the heterogeneous distribution of stardust within the early solar system. In 2020 December, the Japan Aerospace Exploration Agency Hayabusa2 spacecraft returned to Earth the first samples of a primitive asteroid, namely, the Cb-type asteroid Ryugu. This provides a unique opportunity to explore the kinship between primitive asteroids and carbonaceous chondrites. We report high-precision μ 26Mg* and μ 25Mg values of Ryugu samples together with those of CI, CM, CV, and ungrouped carbonaceous chondrites. The stable Mg isotope composition of Ryugu aliquots defines μ 25Mg values ranging from -160 ± 20 ppm to -272 ± 30 ppm, which extends to lighter compositions relative to Ivuna-type (CI) and other carbonaceous chondrite groups. We interpret the μ 25Mg variability as reflecting heterogeneous sampling of a carbonate phase hosting isotopically light Mg (μ 25Mg ~ -1400 ppm) formed by low temperature equilibrium processes. After correcting for this effect, Ryugu samples return homogeneous μ 26Mg* values corresponding to a weighted mean of 7.1 ± 0.8 ppm. Thus, Ryugu defines a μ 26Mg* excess relative to the CI and CR chondrite reservoirs corresponding to 3.8 ± 1.1 and 11.9 ± 0.8 ppm, respectively. These variations cannot be accounted for by in situ decay of 26Al given their respective 27Al/24Mg ratios. Instead, it requires that Ryugu and the CI and CR parent bodies formed from material with a different initial 26Al/27Al ratio or that they are sourced from material with distinct Mg isotope compositions. Thus, our new Mg isotope data challenge the notion that Ryugu and CI chondrites share a common nucleosynthetic heritage.

Keywords: Meteorite composition, Asteroids, Nucleosynthesis, Carbonaceous chondrites, Solar system evolution
J0107a: A Barred Spiral Dusty Star-forming Galaxy at z = 2.467. Dusty star-forming galaxies (DSFGs) are among the most massive and active star-forming galaxies during the cosmic noon. Theoretical studies have proposed various formation mechanisms of DSFGs, including major merger-driven starbursts and secular star-forming disks. Here, we report J0107a, a bright (~8 mJy at observed-frame 888 μm) DSFG at z = 2.467 that appears to be a gas-rich massive disk and might be an extreme case of the secular disk scenario. J0107a has a stellar mass M ⋆ ~ 5 × 1011 M ⊙, molecular gas mass M mol ≳ 1011 M ⊙, and a star formation rate of ~500M ⊙ yr-1. J0107a does not have a gas-rich companion. The rest-frame 1.28 μm JWST NIRCam image of J0107a shows a grand-design spiral with a prominent stellar bar extending ~15 kpc. The Atacama Large Millimeter/submillimeter Array Band 7 continuum map reveals that the dust emission originates from both the central starburst and the stellar bar. 3D disk modeling of the CO(4-3) emission line indicates a dynamically cold disk with rotation-to-dispersion ratio ${V}_{\max }/\sigma \sim 8$ . The results suggest a bright DSFG may have a nonmerger origin, and its vigorous star formation may be triggered by the bar and/or rapid gas inflow.

Keywords: Galaxy formation, CO line emission, Barred spiral galaxies, Ultraluminous infrared galaxies, High-redshift galaxies
RNO 54: A Previously Unappreciated FU Ori Star. We present evidence in support of the hypothesis that the young stellar object RNO 54 is a mature-stage FU Ori type source. The star was first cataloged as a "red nebulous object" in the 1980s but appears to have undergone its outburst prior to the 1890s. Present-day optical and near-infrared spectra are consistent with those of other FU Ori-type stars, both in the details of spectral line presence and shape, and in the overall change in spectral type from an FGK-type in the optical, to the M-type presented in the near-infrared. In addition, the spectral energy distribution of RNO 54 is well-fit by a pure-accretion disk model with parameters: $\dot{M}={10}^{-3.45\pm 0.06}$ M ☉ yr-1, M * = 0.23 ± 0.06 M ☉, and R inner = 3.68 ± 0.76 R ☉, though we believe R inner is likely close to its upper range of 4.5R ☉ in order to produce a ${T}_{\max }=7000$ K that is consistent with the optical to near-infrared spectra. The resulting L acc is ~265 L ☉. To find these values, we adopted a source distance d = 1400 pc and extinction A  V  = 3.9 mag, along with disk inclination i = 50 deg based on the consideration of confidence intervals from our initial disk model, and in agreement with observational constraints. The new appreciation of a well-known source as an FU Ori-type object suggests that other such examples may be lurking in extant samples.

Keywords: Young stellar objects, Eruptive variable stars, FU Orionis stars
Influence of Intermittency on the Energy Transfer Rate of Solar Wind Turbulence. The intermittency in the solar wind turbulence manifests itself in the anisotropic scaling due to the anisotropic spectral index and the intermittent level based on the extended P model. However, the influence of intermittency on the energy transfer rate remains unclear. Here we apply the partial variance of increments method to identify the intermittency for the magnetic field measurements in the fast solar wind from the Ulysses spacecraft. We distinguish the sampling direction using the angle θ RB between the local magnetic field and radial direction to study the anisotropy. We perform the multiorder structure function analyses and adopt the log-Poisson cascade model to describe the role of intermittency in the cascade process. We find that the anisotropy of the scaling becomes isotropic with a complete removal of intermittency. We compare explicitly the anisotropy of the energy transfer rate before and after removing the intermittency for the same interval for the first time. We find a distinct anisotropy with a cascade enhancement in the direction perpendicular to the local magnetic field. The removal of the intermittency greatly weakens the anisotropy by mainly reducing the perpendicular energy transfer rate. Our findings suggest that the intermittency effectively enhances the energy transfer rate, in particular in the perpendicular direction in the solar wind turbulence.

Keywords: Interplanetary turbulence, Magnetohydrodynamics, Interplanetary magnetic fields, Fast solar wind