Sazuna/UAT_keywords huggingface dataset:
Neutrinos and Gamma Rays from Galaxy Clusters Constrained by the Upper Limits of IceCube. Clusters of galaxies possess the capability to accelerate cosmic rays (CRs) to very high energy up to ~1018 eV due to their large size and magnetic field strength, which favor CR confinement for cosmological times. During their confinement, they can produce neutrinos and γ-rays out of interactions with the background gas and photon fields. In recent work, Hussain et al. have conducted three-dimensional cosmological magnetohydrodynamical simulations of the turbulent intracluster medium combined with multidimensional Monte Carlo simulations of CR propagation for redshifts ranging from z ~ 5 to z = 0 to study the multimessenger emission from these sources. They found that when CRs with a spectral index in the range 1.5-2.5 and cutoff energy ${E}_{\max }={10}^{16}\mbox{--}{10}^{17}$ eV are injected into the system, they make significant contributions to the diffuse background emission of both neutrinos and γ-rays. In this work, we have revisited this model and undertaken further constraints on the parametric space. This was achieved by incorporating the recently established upper limits on neutrino emission from galaxy clusters, as obtained by the IceCube experiment. We find that for CRs injected with spectral indices in the range 2.0-2.5, cutoff energy ${E}_{\max }={10}^{16}\mbox{--}{10}^{17}$ eV, and power corresponding to (0.1-1)% of the cluster luminosity, our neutrino flux aligns with the upper limits estimated by IceCube. Additionally, the resulting contribution from clusters to the diffuse γ-ray background remains significant with values of the order of ~10-5 MeV cm-2 s-1 sr-1 at energies above 500 GeV.

Keywords: Neutrino astronomy
X-Rays from RS Ophiuchi's 2021 Eruption: Shocks In and Out of Ionization Equilibrium. The recurrent nova RS Ophiuchi (RS Oph) underwent its most recent eruption on 2021 August 8 and became the first nova to produce both detectable GeV and TeV emission. We used extensive X-ray monitoring with the Neutron Star Interior Composition Explorer Mission (NICER) to model the X-ray spectrum and probe the shock conditions throughout the 2021 eruption. The rapidly evolving NICER spectra consisted of both line and continuum emission that could not be accounted for using a single-temperature collisional equilibrium plasma model with an absorber that fully covered the source. We successfully modeled the NICER spectrum as a nonequilibrium ionization collisional plasma with partial covering absorption. The temperature of the nonequilibrium plasma shows a peak on day 5 with a kT of approximately 24 keV. The increase in temperature during the first five days could have been due to increasing contribution to the X-ray emission from material behind fast polar shocks or a decrease is the amount of energy being drained from the shocks into particle acceleration during that period. The absorption showed a change from fully covering the source to having a covering fraction of roughly 0.4, suggesting a geometrical evolution of the shock region within the complex global distribution of the circumstellar material. These findings show evidence of the ejecta interacting with some dense equatorial shell initially, and with less dense material in the bipolar regions at later times during the eruption.

Keywords: High energy astrophysics, Plasma astrophysics, Astronomy data analysis, Recurrent novae
First Results from the JWST Early Release Science Program Q3D: Powerful Quasar-driven Galactic Scale Outflow at z = 3. Quasar-driven galactic outflows are a major driver of the evolution of massive galaxies. We report observations of a powerful galactic-scale outflow in a z = 3 extremely red and intrinsically luminous (L bol ≃ 5 × 1047erg s-1) quasar SDSSJ1652 + 1728 with the Near-infrared Spectrograph on board JWST. We analyze the kinematics of rest-frame optical emission lines and identify the quasar-driven outflow extending out to ~10 kpc from the quasar with a velocity offset of (v  r  = ± 500 km s-1) and high velocity dispersion (FWHM = 700-2400 km s-1). Due to JWST's unprecedented surface brightness sensitivity in the near-infrared, we unambiguously show that the powerful high velocity outflow in an extremely red quasar encompasses a large swath of the host galaxy's interstellar medium. Using the kinematics and dynamics of optical emission lines, we estimate the mass outflow rate-in the warm ionized phase alone-to be at least 2300 ± 1400 M ☉ yr-1. We measure a momentum flux ratio between the outflow and the quasar accretion disk of ~1 on a kpc scale, indicating that the outflow was likely driven in a relatively high (&gt;1023cm-2) column density environment through radiation pressure on dust grains. We find a coupling efficiency between the bolometric luminosity of the quasar and the outflow of 0.1%, matching the theoretical prediction of the minimum coupling efficiency necessary for negative quasar feedback. The outflow has sufficient energetics to drive the observed turbulence seen in shocked regions of the quasar host galaxy, which are likely directly responsible for prolonging the time that it takes for gas to cool efficiently.

Keywords: AGN host galaxies, Galaxy evolution, Quasars
Astrochemical Diagnostics of the Isolated Massive Protostar G28.20-0.05. We study the astrochemical diagnostics of the isolated massive protostar G28.20-0.05. We analyze data from Atacama Large Millimeter/submillimeter Array 1.3 mm observations with a resolution of 0.″2 (~1000 au). We detect emission from a wealth of species, including oxygen-bearing (e.g., H2CO, CH3OH, CH3OCH3), sulfur-bearing (SO2, H2S), and nitrogen-bearing (e.g., HNCO, NH2CHO, C2H3CN, C2H5CN) molecules. We discuss their spatial distributions, physical conditions, correlation between different species, and possible chemical origins. In the central region near the protostar, we identify three hot molecular cores (HMCs). HMC1 is part of a millimeter continuum ring-like structure, is closest in projection to the protostar, has the highest temperature of ~300 K, and shows the most line-rich spectra. HMC2 is on the other side of the ring, has a temperature of ~250 K, and is of intermediate chemical complexity. HMC3 is further away, ~3000 au in projection, cooler (~70 K), and is the least line-rich. The three HMCs have similar mass surface densities (~10 g cm-2), number densities (n H ~ 109 cm-3), and masses of a few solar masses. The total gas mass in the cores and in the region out to 3000 au is ~25 M ⊙, which is comparable to that of the central protostar. Based on spatial distributions of peak line intensities as a function of excitation energy, we infer that the HMCs are externally heated by the protostar. We estimate column densities and abundances of the detected species and discuss the implications for hot core astrochemistry.

Keywords: Massive stars, Spectral line identification, Astrochemistry, Star formation, Interstellar medium, Complex organic molecules
Detecting Fast Radio Bursts with Spectral Structure Using the Continuous Forward Algorithm. Detecting fast radio bursts (FRBs) with frequency-dependent intensity remains a challenge, as existing search algorithms do not account for the spectral shape, potentially leading to nondetections. We propose a novel detection statistic, which we call the Kalman detector, that improves the sensitivity of FRB signal detection by incorporating spectral shape information. The detection statistic is based on an optimal matched filter, marginalizing over all possible intensity functions, weighted by a random walk probability distribution, considering some decorrelation bandwidth. Our analysis of previously detected FRBs demonstrates that the Kalman score provides a comparable yet independent source of information for bursts with significant spectral structure, and the sensitivity improvement is of the order 0%-200% with a median improvement of 20%. We also applied the Kalman detector to existing data from FRB 20201124A and detected two new repeat bursts that were previously missed. Furthermore, we suggest a practical implementation for real-time surveys by employing a low significance soft-trigger from initial flux integration-based detection algorithms. The Kalman detector has the potential to significantly enhance FRB detection capabilities and enable new insights into the spectral properties of these enigmatic astrophysical phenomena.

Keywords: Astrostatistics techniques, Astronomy data analysis, Interstellar scintillation, Radio astronomy, Radio transient sources
Magnetic Fields and Plasma Heating in the Sun's Atmosphere. We use the first publicly available data from the Daniel K. Inouye Solar Telescope to track magnetic connections from the solar photosphere into the corona. We scrutinize relationships between chromospheric magnetism and bright chromospheric, transition region, and coronal plasmas. In 2022 June, the Visible Spectro-Polarimeter (ViSP) instrument targeted unipolar network within a decaying active region. ViSP acquired rastered scans with longitudinal Zeeman sensitivities of 0.25 Mx cm-2 (Fe I, 630.2 nm) and 0.5 Mx cm-2 (Ca II, 854.2 nm). ViSP was operated in a "low" resolution mode (0.″214 slit width, spectral resolution ${ \mathcal R }\approx {\rm{70,000}}$ ) to produce polarization maps over a common area of 105″ × 50″. Data from the Solar Dynamics Observatory and Interface Region Imaging Spectrograph are combined to ask: Why is only a fraction of emerging flux filled with heated plasma? What is the elemental nature of the plasmas? No correlations were found between heated plasma and the properties of chromospheric magnetic fields derived from the weak field approximation, on scales below supergranules. Processes hidden from our observations control plasma heating. While improved magnetic measurements are needed, these data indicate that "the corona is a self-regulating forced system." Heating depends on the state of the corona, not simply on boundary conditions. Heating models based upon identifiable bipolar fields, including cool loops, tectonics, and observable magnetic reconnection, are refuted for these regions with unipolar chromospheric magnetic fields.

Keywords: Solar chromospheric heating, Magnetohydrodynamics, Solar coronal heating, Solar magnetic fields
Evidence of a Thick Heliopause Boundary Layer Resulting from Active Magnetic Reconnection with the Interstellar Medium. Voyager 1 and 2 data from the vicinity of the heliopause and very local interstellar medium are reexamined to better understand the confounding lack of rotation in the magnetic field (B-field) across the heliopause observed by both Voyagers, despite their very large spatial separations (&gt;100 au). Using three estimates for the orientation of the B-field in the pristine interstellar medium and four models of the heliosphere, we calculate draped interstellar B-field orientations along the model heliopauses and compare those estimates to the Voyager observations. At both Voyagers, expected draped B-fields are inconsistent with the observed B-field orientations after the boundary crossings. Furthermore, we show how the longer-term trends of the observed B-fields at both Voyagers after the crossings actually rotated away from both the expected draped B-field and the pristine interstellar B-field directions. We develop evidence, including an illustrative and analogous set of observations from Magnetospheric Multiscale spacecraft along Earth's magnetopause, in support of a hypothesis that both Voyagers transited a thick boundary layer of reconnected magnetic flux along the heliopause surface. We estimate that Voyager 1 has not yet fully transited this boundary layer, the radial thickness of which at the Voyager 1 crossing location may be &gt;18 au and likely much thicker. Meanwhile, at Voyager 2's crossing location, the boundary layer is likely much thinner, and for Voyager 2, we present evidence that Voyager 2 might already have transited the boundary layer and entered a region of fields and plasma that were never connected to the Sun-the very local interstellar medium.

Keywords: Heliopause, Astrospheres, Magnetohydrodynamics, Stellar-interstellar interactions, Solar magnetic reconnection, Heliosphere, Plasma astrophysics, Interstellar medium, Heliosheath
Spherical Harmonics for the 1D Radiative Transfer Equation. II. Thermal Emission. Approximate methods for radiative transfer equations that are fast, reliable, and accurate are essential for the understanding of atmospheres of exoplanets and brown dwarfs. The simplest and most popular choice is the "two-stream method," which is often used to produce simple yet effective models for radiative transfer in scattering and absorbing media. Toon et al. (hereafter, Toon89) outlined a two-stream method for computing reflected light and thermal spectra that was later implemented in the open-source radiative transfer model PICASO. In Part I of this series, we developed an analytical spherical harmonics method for solving the radiative transfer equation for reflected solar radiation that was implemented in PICASO to increase the accuracy of the code by offering a higher-order approximation. This work is an extension of this spherical harmonics derivation, to study thermal emission spectroscopy. We highlight the model differences in the approach for thermal emission and benchmark the four-term method (SH4) against Toon89 and a high-stream discrete-ordinates method, CDISORT. By comparing the spectra produced by each model, we demonstrate that the SH4 method provides a significant increase in accuracy, compared to Toon89, which can be attributed to the increased order of approximation and to the choice of phase function. We also explore the trade-off between computational time and model accuracy. We find that our four-term method is twice as slow as our two-term method, but is up to five times more accurate, when compared with CDISORT. Therefore, SH4 provides excellent improvement in model accuracy with minimal sacrifice in numerical expense.

Keywords: Exoplanets, Radiative transfer equation, Radiative transfer, Exoplanet atmospheres
Identification of Galaxy Protoclusters Based on the Spherical Top-hat Collapse Theory. We propose a new method for finding galaxy protoclusters that is motivated by structure formation theory and also directly applicable to observations. We adopt the conventional definition that a protocluster is a galaxy group whose virial mass M vir &lt; M cl at its epoch, where M cl = 1014 M ⊙, but would exceed that limit when it evolves to z = 0. We use the critical overdensity for complete collapse at z = 0 predicted by the spherical top-hat collapse model to find the radius and total mass of the regions that would collapse at z = 0. If the mass of a region centered at a massive galaxy exceeds M cl, the galaxy is at the center of a protocluster. We define the outer boundary of a protocluster as the zero-velocity surface at the turnaround radius so that the member galaxies are those sharing the same protocluster environment and showing some conformity in physical properties. We use the cosmological hydrodynamical simulation Horizon Run 5 (HR5) to calibrate this prescription and demonstrate its performance. We find that the protocluster identification method suggested in this study is quite successful. Its application to the high-redshift HR5 galaxies shows a tight correlation between the mass within the protocluster regions identified according to the spherical collapse model and the final mass to be found within the clusters at z = 0, meaning that the regions can be regarded as the bona fide protoclusters with high reliability. We also confirm that the redshift-space distortion does not significantly affect the performance of the protocluster identification scheme.

Keywords: Galaxy formation, High-redshift galaxy clusters, Galaxy dynamics, Galaxy kinematics, Galaxy evolution, Galaxies
Measuring the Milky Way Vertical Potential with the Phase Snail in a Model-independent Way. The vertical phase-space spiral (snail) is a direct sign of disequilibrium of the Milky Way's disk. Nevertheless, the wrapping of the phase snail contains information on the vertical potential. We propose a novel method to measure the vertical potential utilizing the intersections between the snail and z/V  z  axes, for which we know the maximum vertical heights (Z max) or velocities ( ${V}_{z,\max }$ ). Using a refined linear interpolation method, we directly obtain $({Z}_{\max },\tfrac{1}{2}{V}_{z,\max }^{2})$ for these snail intersections to constrain the vertical potential profile empirically. Our method is model-independent, since no assumptions about the snail shape or the vertical potential have been made. Although the snail binned by the guiding center radius (R  g ) is more prominent, it traces a vertical potential shallower than that of the snail binned by the same galactocentric radius (R). We apply an empirical method to correct this difference. We measure the snail intersections in several R  g  bins within 7.5 &lt; R  g  &lt; 11.0 kpc for Gaia DR3 and apply the interpolation method to deduce the potential values at several vertical heights. The potential at the snail intersections, as well as the following mass modeling, is consistent with the popular Milky Way potentials in the literature. For the R  g -binned phase snail in the solar neighborhood, the mass modeling indicates a local dark matter density of ρ dm = 0.0150 ± 0.0031 M ⊙ pc-3, consistent with previous works. Our method could be applied to larger radial ranges in future works to provide independent and stronger constraints on the Milky Way's potential.

Keywords: Stellar kinematics, Galaxy structure, Milky Way dynamics, Stellar dynamics, Milky Way disk
First Detection of an Overmassive Black Hole Galaxy UHZ1: Evidence for Heavy Black Hole Seed Formation from Direct Collapse. The recent Chandra-JWST discovery of a quasar in the z ≈ 10.1 galaxy UHZ1 reveals that accreting supermassive black holes were already in place 470 million years after the Big Bang. The Chandra X-ray source detected in UHZ1 is a Compton-thick quasar with a bolometric luminosity of L bol ~ 5 × 1045 erg s-1, which corresponds to an estimated black hole (BH) mass of ~4 × 107 M ⊙, assuming accretion at the Eddington rate. JWST NIRCAM and NIRSpec data yield a stellar mass estimate for UHZ1 comparable to its BH mass. These characteristics are in excellent agreement with prior theoretical predictions for a unique class of transient, high-redshift objects, overmassive black hole galaxies (OBGs) by Natarajan et al., that harbor a heavy initial black hole seed that likely formed from the direct collapse of the gas. Given the excellent agreement between the observed multiwavelength properties of UHZ1 and theoretical model template predictions, we suggest that UHZ1 is the first detected OBG candidate. Our assertion rests on multiple lines of concordant evidence between model predictions and the following observed properties of UHZ1: its X-ray detection and the estimated ratio of the X-ray flux to the IR flux, which is consistent with theoretical expectations for a heavy initial BH seed; its high measured redshift of z ≈ 10.1, as predicted for the transient OBG stage (9 &lt; z &lt; 12); the amplitude and shape of the detected JWST spectral energy distribution (SED) between 1 and 5 μm, which is in very good agreement with simulated template SEDs for OBGs; and the extended JWST morphology of UHZ1, which is suggestive of a recent merge and is also expected for the formation of transient OBGs. As the first OBG candidate, UHZ1 provides compelling evidence for the formation of heavy initial seeds from direct collapse in the early Universe.

Keywords: Supermassive black holes, Black holes, Astrophysical black holes, Quasars
High Hard X-Ray Polarization in Cygnus X-1 Confined to the Intermediate Hard State: Evidence for a Variable Jet Component. Cygnus X-1, the well-known accreting black hole system, exhibits several observational features hinting at an intricate interplay between the accretion disk, its atmosphere known as the corona, and the putative relativistic jet. It has been extensively studied using all available observational methods, including using the newly available technique of sensitive X-ray polarimetry. X-ray polarization characteristics are distinct for coronal and jet emissions. The low X-ray polarization measured below ~100 keV is understood as arising from the corona. In contrast, the high polarization measurements reported above ~400 keV required a separate jet-dominated spectral component, which spectroscopy does not demonstrate conclusively. Here we report precise polarization measurements in the 100-380 keV region made during three different subclasses of spectral states of the source using the CZTI instrument onboard AstroSat. A high polarization (23% ± 4%) is found mainly in the Intermediate Hard State of the source, and the energy-resolved measurements smoothly connect the coronal and the jet regimes. When high polarization is observed, the simultaneous spectral data hints at a separate power-law component above 100 keV. We examine the possible sources of this energy-dependent high polarization in Cygnus X-1.

Keywords: X-ray astronomy, Jets, Radio jets, X-ray detectors, High mass x-ray binary stars, Stellar mass black holes, X-ray telescopes, Spectroscopy, Polarimetry
New Mass and Radius Constraints on the LHS 1140 Planets: LHS 1140 b Is either a Temperate Mini-Neptune or a Water World. The two-planet transiting system LHS 1140 has been extensively observed since its discovery in 2017, notably with Spitzer, HST, TESS, and ESPRESSO, placing strong constraints on the parameters of the M4.5 host star and its small temperate exoplanets, LHS 1140 b and c. Here, we reanalyze the ESPRESSO observations of LHS 1140 with the novel line-by-line framework designed to fully exploit the radial velocity content of a stellar spectrum while being resilient to outlier measurements. The improved radial velocities, combined with updated stellar parameters, consolidate our knowledge of the mass of LHS 1140 b (5.60 ± 0.19 M ⊕) and LHS 1140 c (1.91 ± 0.06 M ⊕) with an unprecedented precision of 3%. Transits from Spitzer, HST, and TESS are jointly analyzed for the first time, allowing us to refine the planetary radii of b (1.730 ± 0.025 R ⊕) and c (1.272 ± 0.026 R ⊕). Stellar abundance measurements of refractory elements (Fe, Mg, and Si) obtained with NIRPS are used to constrain the internal structure of LHS 1140 b. This planet is unlikely to be a rocky super-Earth, as previously reported, but rather a mini-Neptune with a ~0.1% H/He envelope by mass or a water world with a water-mass fraction between 9% and 19%, depending on the atmospheric composition and relative abundance of Fe and Mg. While the mini-Neptune case would not be habitable, a water-abundant LHS 1140 b potentially has habitable surface conditions according to 3D global climate models, suggesting liquid water at the substellar point for atmospheres with relatively low CO2 concentration, from Earth-like to a few bars.

Keywords: M dwarf stars, Exoplanets, Super Earths, Planetary interior, Habitable planets