Sazuna/UAT_keywords huggingface dataset:
Closing the Gap between Observed Low-mass Galaxy H I Kinematics and Cold Dark Matter Predictions. Testing the standard cosmological model (ΛCDM) at small scales is challenging. Galaxies that inhabit low-mass dark matter halos provide an ideal test bed for dark matter models by linking observational properties of galaxies at small scales (low mass, low velocity) to low-mass dark matter halos. However, the observed kinematics of these galaxies do not align with the kinematics of the dark matter halos predicted to host them, obscuring our understanding of the low-mass end of the galaxy–halo connection. We use deep H I observations of low-mass galaxies at high spectral resolution in combination with cosmological simulations of dwarf galaxies to better understand the connection between dwarf galaxy kinematics and low-mass halos. Specifically, we use H I line widths to directly compare to the maximum velocities in a dark matter halo and find that each deeper measurement approaches the expected one-to-one relationship between the observed kinematics and the predicted kinematics in ΛCDM. We also measure baryonic masses and place these on the baryonic Tully–Fisher relation (BTFR). Again, our deepest measurements approach the theoretical predictions for the low-mass end of this relation, a significant improvement on similar measurements based on line widths measured at 50% and 20% of the peak. Our data also hint at the rollover in the BTFR predicted by hydrodynamical simulations of ΛCDM for low-mass galaxies.

Keywords: Galaxy structure, Dwarf galaxies, Galaxy kinematics, Galaxy evolution, Circumgalactic medium, Dark matter
Dust and Cold Gas Properties of Starburst HyLIRG Quasars at z ∼ 2.5. Some high-z active galactic nuclei (AGNs) are found to reside in extreme star-forming galaxies, such as hyperluminous infrared galaxies (HyLIRGs), with AGN-removed L IR of &gt;1013 L ⊙. In this paper, we report NOEMA observations of six apparent starburst HyLIRGs associated with optical quasars at z ∼ 2–3 in the Stripe 82 field, to study their dust and molecular CO properties. Five out of the six candidates are detected with CO(4–3) or CO(5–4) emission, and four in the 2 mm dust continuum. Based on the linewidth– ${L}_{\mathrm{CO}(1-0)}^{{\prime} }$ diagnostics, we find that four galaxies are likely unlensed or weakly lensed sources. The molecular gas mass is in the range of $\mu {M}_{{{\rm{H}}}_{2}}\,\sim 0.8\mbox{-}9.7\times {10}^{10}\,{M}_{\odot }$ (with $\alpha =0.8\,{M}_{\odot }{\left({\rm{K}}\,\mathrm{km}\,{{\rm{s}}}^{-1}\,{\mathrm{pc}}^{2}\right)}^{-1}$ , where μ is the unknown possible gravitational magnification factor). We fit their spectral energy distributions, after including the observed 2 mm fluxes and upper limits, and estimate their apparent (uncorrected for possible lensing effects) star formation rates (μSFRs) to be ∼400–2500 M ⊙ yr‑1, with a depletion time of ∼20–110 Myr. We notice interesting offsets, of ∼10–40 kpc spatially or ∼1000–2000 km s‑1 spectroscopically, between the optical quasar and the millimeter continuum or CO emissions. The observed velocity shift is likely related to the blueshifted broad-emission-line region of quasars, though mergers or recoiling black holes are also possible causes, which can explain the spatial offsets and the high intrinsic star formation rates in the HyLIRG quasar systems.

Keywords: Starburst galaxies, Quasars, Millimeter-wave spectroscopy, Galaxy evolution, CO line emission, Interferometry
1991T-Like Type Ia Supernovae as an Extension of the Normal Population. Type Ia supernovae (SNe) remain poorly understood despite decades of investigation. Massive computationally intensive hydrodynamic simulations have been developed and run to model an ever-growing number of proposed progenitor channels. Further complicating the matter, a large number of subtypes of Type Ia SNe have been identified in recent decades. Due to the massive computational load required, inference of the internal structure of Type Ia SNe ejecta directly from observations using simulations has previously been computationally intractable. However, deep-learning emulators for radiation transport simulations have alleviated such barriers. We perform abundance tomography on 40 Type Ia SNe from optical spectra using the radiative transfer code TARDIS accelerated by the probabilistic DALEK deep-learning emulator. We apply a parametric model of potential outer ejecta structures to comparatively investigate abundance distributions and internal ionization fractions of intermediate-mass elements (IMEs) between normal and 1991T-like Type Ia SNe in the early phases. Our inference shows that the outer ejecta of 1991T-like Type Ia SNe is underabundant in the typical intermediate mass elements that heavily contribute to the spectral line formation seen in normal Type Ia SNe at early times. Additionally, we find that the IMEs present in 1991T-like Type Ia SNe are highly ionized compared to those in the normal Type Ia population. Finally, we conclude that the transition between normal and 1991T-like Type Ia SNe appears to be continuous observationally and that the observed differences come out of a combination of both abundance and ionization fractions in these SNe populations.

Keywords: Bayesian statistics, Type Ia supernovae, Spectroscopy, Neural networks
The Atacama Cosmology Telescope: Millimeter Observations of a Population of Asteroids or: ACTeroids. We present fluxes and light curves for a population of asteroids at millimeter wavelengths, detected by the Atacama Cosmology Telescope (ACT) over 18,000 deg2 of the sky using data from 2017 to 2021. We utilize high cadence maps, which can be used in searching for moving objects such as asteroids and trans-Neptunian Objects, as well as for studying transients. We detect 170 asteroids with a signal-to-noise of at least 5 in at least one of the ACT observing bands, which are centered near 90, 150, and 220 GHz. For each asteroid, we compare the ACT measured flux to predicted fluxes from the near-Earth asteroid thermal model fit to WISE data. We confirm previous results that detected a deficit of flux at millimeter wavelengths. Moreover, we report a spectral characteristic to this deficit, such that the flux is relatively lower at 150 and 220 GHz than at 90 GHz. Additionally, we find that the deficit in flux is greater for S-type asteroids than for C-type.

Keywords: Millimeter astronomy, Cosmic microwave background radiation, Asteroids
First Direct Imaging of a Kelvin─Helmholtz Instability by PSP/WISPR. We present a comprehensive analysis aimed at proving the hypothesis that a train of small-scale features observed by the Wide-field Imager (WISPR) onboard the Parker Solar Probe (PSP) are the signature of a Kelvin─Helmholtz instability (KHI). These features were seen near the flank of a Coronal Mass Ejection (CME) wake between 7.5 R ☉ and 9.5 R ☉, lasting for about 30 minutes. The CME was a slow event, associated with a streamer blowout. We analyzed the size of the eddies and found growth during their evolution while maintaining separation distances and alignment typical of Kelvin─Helmholtz vortexes. We then assessed the magnetic field conditions that would make the observation of such an instability plausible. Two methods were used to cross-check our findings. The measured thickness of the boundary layer supports KHI candidacy, and the estimated linear growth rate suggests nonlinear saturation within the expected timescale. We conclude that a KHI is a plausible explanation for the observed features, and therefore that such instabilities might exist in the low and middle solar corona (within ∼15 R ☉) and can be detected in white light observations. Their observation, however, might be rare due to stringent conditions like the observer's proximity, suitable viewing circumstances, magnetic field topology, and flow properties. This study highlights the unique capability of PSP/WISPR in observing such phenomena, especially as PSP perihelia reach closer distances to the Sun.

Keywords: Heliosphere, The Sun, Solar wind, Solar coronal mass ejections, Solar corona
Cracking the Relation between Mass and 1P Star Fraction of Globular Clusters. I. Present-day Cluster Masses as a First Tool. The phenomenon of multiple stellar populations is exacerbated in massive globular clusters, with the fraction of first-population (1P) stars a decreasing function of the cluster present-day mass. We decipher this relation in far greater detail than has been done so far. We assume (i) a fixed stellar mass threshold for the formation of second-population (2P) stars, (ii) a power-law scaling ${F}_{1{\rm{P}}}\propto {m}_{\mathrm{ecl}}^{-1}$ between the mass m ecl of newly formed clusters and their 1P star fraction F 1P, and (iii) a constant F 1P over time. The F 1P(m ecl) relation is then evolved up to an age of 12 Gyr for tidal field strengths representative of the entire Galactic halo. The 12 Gyr old model tracks cover the present-day distribution of Galactic globular clusters in the (mass, F 1P) space extremely well. The distribution is curtailed on its top right side by the scarcity of clusters at large Galactocentric distances and on its bottom left side by the initial scarcity of very high-mass clusters and dynamical friction. Given their distinct dissolution rates, "inner" and "outer" model clusters are offset from each other, as observed. The locus of Magellanic Clouds clusters in the (mass, F 1P) space is as expected for intermediate-age clusters evolving in a gentle tidal field. Given the assumed constancy of F 1P, we conclude that 2P stars do not necessarily form centrally concentrated. We infer a minimum mass of 4 · 105 M ⊙ for multiple-population clusters at secular evolution onset. This high-mass threshold severely limits the number of 2P stars lost from evolving clusters, thereby fitting the low 2P star fraction of the Galactic halo field.

Keywords: Globular star clusters, Stellar populations, Fornax dwarf spheroidal galaxy, Stellar dynamics, Chemical abundances, Chemical enrichment, Population II stars, Magellanic Clouds, Milky Way Galaxy
Different Dependence of Narrow Hα Line Luminosity on Optical Continuum Luminosity between Star-forming Galaxies and Type 2 Active Galactic Nuclei: Globally Negative AGN Feedback in Local Type 2 AGN?. In this manuscript, clues are provided to support globally negative active galactic nuclei (AGN) feedback on star formation in the host galaxies of the local low-redshift Sloan Digital Sky Survey (SDSS) Type 2 AGN, based on the different dependence of narrow Hα line luminosity L Hα  on optical continuum luminosity λ L cont between star-forming galaxies and Type 2 AGN. Through the measured L Hα  and λ L cont in SDSS star-forming galaxies, there is a strong linear correlation between λ L cont and L Hα , accepted as a standard correlation without the effects of AGN activity. Meanwhile, considering the apparent contribution of AGN activity to the narrow Hα line emissions in Type 2 AGN, the correlation between λ L cont and L Hα  in the SDSS Type 2 AGN leads to a statistically lower L Hα  in Type 2 AGN than in star-forming galaxies, with a significance level higher than 5σ, even after considering necessary effects (including effects of host galaxy properties), leading to the accepted conclusion on the globally negative AGN feedback in the local Type 2 AGN. Meanwhile, the properties of Dn(4000) and Hδ  A  can provide indirect clues to support the globally negative AGN feedback in local Type 2 AGN, due to older stellar ages in Type 2 AGN. Moreover, it is interesting to expect more than 50% narrow Hα emissions globally suppressed in the host galaxies of Type 2 AGN relative to the star-forming galaxies. The results not only support globally negative AGN feedback in local Type 2 AGN, but also show further clues on the quantification of suppressions of star formation by the globally negative AGN feedback.

Keywords: AGN host galaxies, Active galaxies, Active galactic nuclei, Emission line galaxies
Relative Yield of Thermal and Nonthermal Emission during Weak Flares Observed by STIX during 2021 September 20–25. The disparate nature of the thermal–nonthermal energy partition during flares, particularly during weak flares, is still an open issue. Following the Neupert effect, quantifying the relative yield of X-ray emission in different energy bands can enable the inferring of the underlying energy release mechanism. During 2021 September 20–25, the Solar Orbiter mission—being closer to the Sun (∼0.6 au) and having a moderate separation angle (&lt;40°) from the Sun–Earth line—offered a unique opportunity to analyze multiwavelength emission from ∼200 (mostly weak) flares, commonly observed by the Spectrometer Telescope for Imaging X-rays (STIX), STEREO-A, GOES, and the Solar Dynamics Observatory. Associating the quotient (q  f ) of hard X-ray fluence (12–20 keV) and soft X-ray flux (4–10 keV) with the peak soft X-ray flux enabled us to identify strongly nonthermal flares. A multiwavelength investigation of spectral and imaging-mode observations of the 20 strongly nonthermal weak flares reveals an inverse relationship of q  f  with the emission measure (and density), and a positive relationship with the flare plasma temperature. This indicates that the plasma in tenuous loops attains higher temperatures compared to that in the denser loops, in response to nonthermal energy deposition. This is in agreement with the plasma parameters of the coronal loops, as derived by applying the one-dimensional Palermo–Harvard hydrodynamical code to coronal loop plasma with different initial coronal loop base pressures when subjected to similar heating inputs. Our investigation, therefore, indicates that the plasma parameters of the flaring loop in the initial phase have a decisive role in the thermal–nonthermal energy partitioning.

Keywords: Solar atmosphere, Solar flares, Solar extreme ultraviolet emission, Solar coronal loops, The Sun, Solar flare spectra, Solar x-ray flares
Constraining the Onset Density for the QCD Phase Transition with the Neutrino Signal from Core-collapse Supernovae. The occurrence of a first-order hadron–quark matter phase transition at high baryon densities is investigated in astrophysical simulations of core-collapse supernovae, to decipher yet incompletely understood properties of the dense matter equation of state (EOS) using neutrinos from such cosmic events. It is found that the emission of a nonstandard second neutrino burst, dominated by electron antineutrinos, is not only a measurable signal for the appearance of deconfined quark matter but also reveals information about the state of matter at extreme conditions encountered at the supernova (SN) interior. To this end, a large set of spherically symmetric SN models is investigated, studying the dependence on the EOS and the stellar progenitor. General relativistic neutrino-radiation hydrodynamics is employed featuring three-flavor Boltzmann neutrino transport and a microscopic hadron-quark hybrid matter EOS class. Therefore, the DD2 relativistic mean-field hadronic model is employed, and several variations of it, and the string-flip model for the description of deconfined quark matter. The resulting hybrid model covers a representative range of onset densities for the phase transition and latent heats. This facilitates the direct connection between intrinsic signatures of the neutrino signal and properties of the EOS. In particular, a set of linear relations has been found empirically. These potentially provide a constraint for the onset density of a possible QCD phase transition from the future neutrino observation of the next galactic core-collapse SN, if a millisecond electron anti-neutrino burst is present around or less than 1 s.

Keywords: Supernova neutrinos, High energy astrophysics, Hydrodynamics, Compact objects, Supernova dynamics
Conditions for Relativistic Magnetic Reconnection under the Presence of Shear Flow and Guide Field. The scaling of the relativistic reconnection outflow speed is studied in the presence of both shear flows parallel to the reconnecting magnetic fields and guide fields pointing out of the reconnection plane. In nonrelativistic reconnection, super-Alfvénic shear flows have been found to suppress reconnection. We extend the analytical model of this phenomenon to the relativistic regime and find similar behavior, which is confirmed by particle-in-cell simulations. Unlike the nonrelativistic limit, the addition of a guide field lowers the in-plane Alfvén velocity, contributing to slower outflow jets and the more efficient suppression of reconnection in strongly magnetized plasmas.

Keywords: Plasma astrophysics, Plasma physics
A Modeling Investigation for Solar Flare X-Ray Stereoscopy with Solar Orbiter/STIX and Earth-orbiting Missions. The Spectrometer/Telescope for Imaging X-rays (STIX) on board Solar Orbiter (SolO) provides a unique opportunity to systematically perform stereoscopic X-ray observations of solar flares with current and upcoming X-ray missions at Earth. These observations will produce the first reliable measurements of hard X-ray (HXR) directivity in decades, providing a new diagnostic of the flare-accelerated electron angular distribution and helping to constrain the processes that accelerate electrons in flares. However, such observations must be compared to modeling, taking into account electron and X-ray transport effects and realistic plasma conditions, all of which can change the properties of the measured HXR directivity. Here, we show how HXR directivity, defined as the ratio of X-ray spectra at different spacecraft viewing angles, varies with different electron and flare properties (e.g., electron angular distribution, highest-energy electrons, and magnetic configuration), and how modeling can be used to extract these typically unknown properties from the data. Finally, we present a preliminary HXR directivity analysis of two flares, observed by the Fermi Gamma-ray Burst Monitor and SolO/STIX, demonstrating the feasibility and challenges associated with such observations, and how HXR directivity can be extracted by comparison with the modeling presented here.

Keywords: Solar atmosphere, Solar flares, Solar energetic particles, The Sun, Solar x-ray flares, Active solar corona, Active solar chromosphere
JWST and ALMA Multiple-line Study in and around a Galaxy at z = 8.496: Optical to Far-Infrared Line Ratios and the Onset of an Outflow Promoting Ionizing Photon Escape. We present Atacama Large Millimeter/submillimeter Array (ALMA) deep spectroscopy for a lensed galaxy at z spec = 8.496 with $\mathrm{log}({M}_{\mathrm{star}}/{M}_{\odot })\sim 7.8$ whose optical nebular lines and stellar continuum are detected by JWST/NIRSpec and NIRCam Early Release Observations in the field of SMACS J0723.3–7327. Our ALMA spectrum shows [O III] 88 μm and [C II] 158 μm line detections at 4.0σ and 4.5σ, respectively. The redshift and position of the [O III] line coincide with those of the JWST source, while the [C II] line is blueshifted by 90 km s‑1 with a spatial offset of 0.″5 (≈0.5 kpc in the source plane) from the centroid of the JWST source. The NIRCam F444W image, including [O III] λ5007 and Hβ line emission, spatially extends beyond the stellar components by a factor of &gt;8. This indicates that the z = 8.5 galaxy has already experienced strong outflows as traced by extended [O III] λ5007 and offset [C II] emission, which would promote ionizing photon escape and facilitate reionization. With careful slit-loss corrections and the removal of emission spatially outside the galaxy, we evaluate the [O III] 88 μm/λ5007 line ratio, and derive the electron density n e by photoionization modeling to be ${220}_{-130}^{+230}$ cm‑3, which is comparable with those of z ∼ 2–3 galaxies. We estimate an [O III] 88 μm/[C II] 158 μm line ratio in the galaxy of &gt;4, as high as those of known z ∼ 6–9 galaxies. This high [O III] 88 μm/[C II] 158 μm line ratio is generally explained by the high n e as well as the low metallicity ( ${Z}_{\mathrm{gas}}/{Z}_{\odot }={0.04}_{-0.02}^{+0.02}$ ), high ionization parameter ( $\mathrm{log}U\gt -2.27$ ), and low carbon-to-oxygen abundance ratio (log(C/O) = [‑0.52: ‑0.24]) obtained from the JWST/NIRSpec data; further [C II] follow-up observations will constrain the covering fraction of photodissociation regions.

Keywords: Early universe, Galaxy formation, Galaxy evolution, Interstellar medium, Circumgalactic medium, Reionization
A Unified Model for Bipolar Outflows from Young Stars: Kinematic and Mixing Structures in HH 30. The young stellar source HH 30 is a textbook example of an ionic optical jet originating from a disk in an edge-on system shown by the Hubble Space Telescope. It has a remnant envelope in 12CO observed by the Atacama Large Millimeter/submillimeter Array. The optical jet is characterized by its narrow appearance, large line width at the base, and high temperature inferred from line diagnostics. Three featured structures can be identified, most evident in the transverse position–velocity diagrams: an extremely-high-velocity wide-angle wind component with large spectral widths in the optical, a very-low-velocity ambient surrounding medium seen in 12CO, and a low-velocity region traced by 12CO nested both in velocity and location between the primary wind and ambient environment. A layered cavity with multiple shells forms nested morphological and kinematic structures around the optical jet. The atomic gas originating from the innermost region of the disk attains a sufficient temperature and ionization to emit brightly in forbidden lines as an optical jet. The wide-angle portion expands, forming a low-density cavity. The filamentary 12CO encompassing the wind cavity is mixed and advected inward through the action of the magnetic interplay of the wide-angle wind with the molecular ambient medium. The magnetic interplay results in the layered shells penetrating deeply into the vast cavity of tenuous atomic wind material. The HH 30 system is an ideal manifestation of the unified wind model of Shang et al. (2020, 2023), with clearly distinguishable atomic and molecular species mixed through the atomic lightly ionized magnetized wind and the surrounding cold molecular ambient material.

Keywords: Interstellar line emission, Stellar wind bubbles, Herbig-Haro objects, Stellar jets, Hubble Space Telescope, Young stellar objects, Stellar winds, Star formation, Emission nebulae, CO line emission, Protostars, Collapsing clouds
CMB-S4: Iterative Internal Delensing and r Constraints. The tightest constraints on the tensor-to-scalar ratio r can only be obtained after removing a substantial fraction of the lensing B-mode sample variance. The planned Cosmic Microwave Background (CMB)-S4 experiment (cmb-s4.org) will remove the lensing B-mode signal internally by reconstructing the gravitational lenses from high-resolution observations. We document here a first lensing reconstruction pipeline able to achieve this optimally for arbitrary sky coverage. We make it part of a map-based framework to test CMB-S4 delensing performance and its constraining power on r, including inhomogeneous noise and two non-Gaussian Galactic polarized foreground models. The framework performs component separation of the high-resolution maps, followed by the construction of lensing B-mode templates, which are then included in a parametric small-aperture map cross-spectra-based likelihood for r. We find that the lensing reconstruction and framework achieve the expected performance, compatible with the target σ(r) ≃ 5 · 10‑4 in the absence of a tensor signal, after an effective removal of 92%–93% of the lensing B-mode variance, depending on the simulation set. The code for the lensing reconstruction can also be used for cross-correlation studies with large-scale structures, lensing spectrum reconstruction, cluster lensing, or other CMB lensing-related purposes. As part of our tests, we also demonstrate the joint optimal reconstruction of the lensing potential with the lensing curl potential mode at second order in the density fluctuations.

Keywords: Cosmic inflation, Gravitational waves, Cosmic background radiation, Cosmological parameters