Sazuna/UAT_keywords huggingface dataset:
Dust Hot Spots at 10 au Scales around the Class 0 Binary IRAS 16293-2422 A: A Departure from the Passive Irradiation Model. Characterizing the physical conditions at disk scales in class 0 sources is crucial for constraining the protostellar accretion process and the initial conditions for planet formation. We use ALMA 1.3 and 3 mm observations to investigate the physical conditions of the dust around the class 0 binary IRAS 16293-2422 A down to ~10 au scales. The circumbinary material's spectral index, α, has a median of 3.1 and a dispersion of ~0.2, providing no firm evidence of millimeter-sized grains therein. Continuum substructures with brightness temperature peaks of T b ~ 60-80 K at 1.3 mm are observed near the disks at both wavelengths. These peaks do not overlap with strong variations of α, indicating that they trace high-temperature spots instead of regions with significant optical depth variations. The lower limits to the inferred dust temperature in the hot spots are 122, 87, and 49 K. Depending on the assumed dust opacity index, these values can be several times higher. They overlap with high gas temperatures and enhanced complex organic molecular emission. This newly resolved dust temperature distribution is in better agreement with the expectations from mechanical instead of the most commonly assumed radiative heating. In particular, we find that the temperatures agree with shock heating predictions. This evidence and recent studies highlighting accretion heating in class 0 disks suggest that mechanical heating (shocks, dissipation powered by accretion, etc.) is important during the early stages and should be considered when modeling and measuring properties of deeply embedded protostars and disks.

Keywords: Interstellar molecules, Binary stars, Shocks, Astrochemistry, Dust continuum emission, Protoplanetary disks, Star formation, Protostars
A Localized Kinematic Structure Detected in Atomic Carbon Emission Spatially Coincident with a Proposed Protoplanet in the HD 163296 Disk. Over the past 5 yr, studies of the kinematics in protoplanetary disks have led to the discovery of new protoplanet candidates and several structures linked to possible planet-disk interactions. We detect a localized kinematic bipolar structure in the HD 163296 disk present inside the deepest dust gap at 48 au from atomic carbon line emission. HD 163296's stellar jet and molecular winds have been described in detail in the literature; however, the kinematic anomaly in C I emission is not associated with either of them. Further, the velocity of the kinematic structure points indicates a component fast enough to differentiate it from the Keplerian profile of the disk, and its atomic nature hints at a localized UV source strong enough to dissociate CO and launch a C I outflow or a strong polar flow from the upper layers of the disk. By discarding the stellar jet and previously observed molecular winds, we explore different sources for this kinematic feature in C I emission that could be associated with a protoplanet inflow/outflow or disk winds.

Keywords: Planetary-disk interactions, Protoplanetary disks, Planet formation
Neutrino Cadence of TXS 0506+056 Consistent with Supermassive Binary Origin. On 2022 September 18, an alert by the IceCube Collaboration indicated that a ~170 TeV neutrino arrived in directional coincidence with the blazar TXS 0506+056. This event adds to two previous pieces of evidence that TXS 0506+056 is a neutrino emitter, i.e., a neutrino alert from its direction on 2017 September 22, and a 3σ signature of a dozen neutrinos in 2014/2015. De Bruijn el al. showed that two previous neutrino emission episodes from this blazar could be due to a supermassive binary black hole (SMBBH) central engine where jet precession close to the final coalescence of the binary results in periodic emission. This model predicted a new emission episode consistent with the 2022 September 18 neutrino observation by IceCube. Here, we show that the neutrino cadence of TXS 0506+056 is consistent with an SMBBH origin. We find that the emission episodes are consistent with an SMBBH with mass ratios q ≲ 0.3 for a total black hole mass of M tot ≳ 3 · 108 M ⊙. For the first time, we calculate the characteristic strain of the gravitational wave emission of the binary, and show that the merger could be detectable by LISA for black hole masses &lt;5 · 108 M ⊙ if the mass ratios are in the range 0.1 ≲ q ≲ 0.3. We predict that there can be a neutrino flare existing in the still-to-be-analyzed IceCube data peaking some time between 2019 August and 2021 January if a precessing jet is responsible for all three detected emission episodes. The next flare is expected to peak in the period 2023 January to 2026 August. Further observation will make it possible to constrain the mass ratio as a function of the total mass of the black hole more precisely and would open the window toward the preparation of the detection of SMBBH mergers.

Keywords: Supermassive black holes, High-energy cosmic radiation, Gamma-ray sources, Blazars, Neutrino astronomy, Active galaxies, Secondary cosmic rays, Gravitational waves
Polytropic Behavior in the Structures of Interplanetary Coronal Mass Ejections. The polytropic process characterizes the thermodynamics of space plasma particle populations. The polytropic index, γ, is particularly important as it describes the thermodynamic behavior of the system by quantifying the changes in temperature as the system is compressed or expanded. Using Wind spacecraft plasma and magnetic field data during 1995 February-2015 December, we investigate the thermodynamic evolution in 336 interplanetary coronal mass ejection (ICME) events. For each event, we derive the index γ in the sheath and magnetic ejecta structures, along with the pre- and post-event regions. We then examine the distributions of all γ indices in these four regions and derive the entropic gradient of each, which is indicative of the ambient heating. We find that in the ICME sheath region, where wave turbulence is expected to be highest, the thermodynamics takes longest to recover into the original quasi-adiabatic process, while it recovers faster in the quieter ejecta region. This pattern creates a thermodynamic cycle, featuring a near adiabatic value γ ~ γ  a  (=5/3) upstream of the ICMEs, γ  a  - γ ~ 0.26 in the sheaths, γ  a  - γ ~ 0.13 in the ICME ejecta, and recovers again to γ ~ γ  a  after the passage of the ICME. These results expose the turbulent heating rates in the ICME plasma: the lower the polytropic index from its adiabatic value and closer to its isothermal value, the larger the entropic gradient, and thus, the rate of turbulent heating that heats the ICME plasma.

Keywords: Space plasmas, Polytropes, Solar coronal mass ejections
PHANGS-JWST First Results: Spurring on Star Formation: JWST Reveals Localized Star Formation in a Spiral Arm Spur of NGC 628. We combine JWST observations with Atacama Large Millimeter/submillimeter Array CO and Very Large Telescope MUSE Hα data to examine off-spiral arm star formation in the face-on, grand-design spiral galaxy NGC 628. We focus on the northern spiral arm, around a galactocentric radius of 3-4 kpc, and study two spurs. These form an interesting contrast, as one is CO-rich and one CO-poor, and they have a maximum azimuthal offset in MIRI 21 μm and MUSE Hα of around 40° (CO-rich) and 55° (CO-poor) from the spiral arm. The star formation rate is higher in the regions of the spurs near spiral arms, but the star formation efficiency appears relatively constant. Given the spiral pattern speed and rotation curve of this galaxy and assuming material exiting the arms undergoes purely circular motion, these offsets would be reached in 100-150 Myr, significantly longer than the 21 μm and Hα star formation timescales (both &lt; 10 Myr). The invariance of the star formation efficiency in the spurs versus the spiral arms indicates massive star formation is not only triggered in spiral arms, and cannot simply occur in the arms and then drift away from the wave pattern. These early JWST results show that in situ star formation likely occurs in the spurs, and that the observed young stars are not simply the "leftovers" of stellar birth in the spiral arms. The excellent physical resolution and sensitivity that JWST can attain in nearby galaxies will well resolve individual star-forming regions and help us to better understand the earliest phases of star formation.

Keywords: Star formation, Interstellar medium, Spiral galaxies, Galaxies
Interstellar Meteors Are Outliers in Material Strength. The first interstellar meteor larger than dust was detected by US government sensors in 2014, identified as an interstellar object candidate in 2019, and confirmed by the Department of Defense in 2022. Here, we describe an additional interstellar object candidate in the CNEOS fireball catalog and compare the implied material strength of the two objects, referred to here as IM1 and IM2, respectively. IM1 and IM2 are ranked first and third in terms of material strength out of all 273 fireballs in the CNEOS catalog. Fitting a log-normal distribution to material strengths of objects in the CNEOS catalog, IM1 and IM2 are outliers at the levels of 3.5σ and 2.6σ, respectively. The random sampling and Gaussian probabilities, respectively, of picking two objects with such high material strength from the CNEOS catalog are ~10-4 and ~10-6. If IM2 is confirmed, this implies that interstellar meteors come from a population with material strength characteristically higher than meteors originating from within the solar system. Additionally, we find that if the two objects are representative of a background population on random trajectories, their combined detections imply that ~40% of all refractory elements are locked in meter-scale interstellar objects. Such a high abundance seemingly defies a planetary system origin.

Keywords: Interstellar objects
The Imprint of Intermittent Interchange Reconnection on the Solar Wind. The solar wind is known to be highly structured in space and time. Observations from Parker Solar Probe have revealed an abundance of so-called magnetic switchbacks within the near-Sun solar wind. In this Letter, we use a high-resolution, adaptive-mesh, magnetohydrodynamics simulation to explore the disturbances launched into the solar wind by intermittent/bursty interchange reconnection and how they may be related to magnetic switchbacks. We find that repeated ejection of plasmoid flux ropes into the solar wind produces a curtain of propagating and interacting torsional Alfvénic waves. We demonstrate that this curtain forms when plasmoid flux ropes dynamically realign with the radial field as they are ejected from the current layer and that this is a robust effect of the 3D geometry of the interchange reconnection region. Simulated flythroughs of this curtain in the low corona reveal an Alfvénic patch that closely resembles observations of switchback patches, but with relatively small magnetic field deflections. Therefore, we suggest that switchbacks could be the solar wind imprint of intermittent interchange reconnection in the corona, provided an in situ process subsequently amplifies the disturbances to generate the large deflections or reversals of radial field that are typically observed. That is to say, our results indicate that a combination of low-coronal and inner-heliospheric mechanisms may be required to explain switchback observations.

Keywords: Solar magnetic reconnection, Solar wind, Solar physics, Solar corona, Solar magnetic fields, Solar coronal holes
Model-based Cross-correlation Search for Gravitational Waves from the Low-mass X-Ray Binary Scorpius X-1 in LIGO O3 Data. We present the results of a model-based search for continuous gravitational waves from the low-mass X-ray binary Scorpius X-1 using LIGO detector data from the third observing run of Advanced LIGO and Advanced Virgo. This is a semicoherent search that uses details of the signal model to coherently combine data separated by less than a specified coherence time, which can be adjusted to balance sensitivity with computing cost. The search covered a range of gravitational-wave frequencies from 25 to 1600 Hz, as well as ranges in orbital speed, frequency, and phase determined from observational constraints. No significant detection candidates were found, and upper limits were set as a function of frequency. The most stringent limits, between 100 and 200 Hz, correspond to an amplitude h 0 of about 10-25 when marginalized isotropically over the unknown inclination angle of the neutron star's rotation axis, or less than 4 × 10-26 assuming the optimal orientation. The sensitivity of this search is now probing amplitudes predicted by models of torque balance equilibrium. For the usual conservative model assuming accretion at the surface of the neutron star, our isotropically marginalized upper limits are close to the predicted amplitude from about 70 to 100 Hz; the limits assuming that the neutron star spin is aligned with the most likely orbital angular momentum are below the conservative torque balance predictions from 40 to 200 Hz. Assuming a broader range of accretion models, our direct limits on gravitational-wave amplitude delve into the relevant parameter space over a wide range of frequencies, to 500 Hz or more.

Keywords: Gravitational wave astronomy, Neutron stars, Low-mass x-ray binary stars, Gravitational waves
The Possible Tidal Demise of Kepler's First Planetary System. We present evidence of tidally-driven inspiral in the Kepler-1658 (KOI-4) system, which consists of a giant planet (1.1R J, 5.9M J) orbiting an evolved host star (2.9R ☉, 1.5M ☉). Using transit timing measurements from Kepler, Palomar/WIRC, and TESS, we show that the orbital period of Kepler-1658b appears to be decreasing at a rate $\dot{P}={131}_{-22}^{+20}$ ms yr-1, corresponding to an infall timescale $P/\dot{P}\approx 2.5\,\mathrm{Myr}$ . We consider other explanations for the data including line-of-sight acceleration and orbital precession, but find them to be implausible. The observed period derivative implies a tidal quality factor ${Q}_{\star }^{{\prime} }={2.50}_{-0.62}^{+0.85}\times {10}^{4}$ , in good agreement with theoretical predictions for inertial wave dissipation in subgiant stars. Additionally, while it probably cannot explain the entire inspiral rate, a small amount of planetary dissipation could naturally explain the deep optical eclipse observed for the planet via enhanced thermal emission. As the first evolved system with detected inspiral, Kepler-1658 is a new benchmark for understanding tidal physics at the end of the planetary life cycle.

Keywords: Exoplanet dynamics, Transits, Hot Jupiters, Exoplanet astronomy, Exoplanet evolution, Timing variation methods, Exoplanet tides
Late-time H/He-poor Circumstellar Interaction in the Type Ic Supernova SN 2021ocs: An Exposed Oxygen-Magnesium Layer and Extreme Stripping of the Progenitor. Supernova (SN) 2021ocs was discovered in the galaxy NGC 7828 (z = 0.01911) within the interacting system Arp 144 and subsequently classified as a normal Type Ic SN around peak brightness. Very Large Telescope/FORS2 observations in the nebular phase at 148 days reveal that the spectrum is dominated by oxygen and magnesium emission lines of different transitions and ionization states: O I, [O I], [O II], [O III], Mg I, and Mg II. Such a spectrum has no counterpart in the literature, though it bears a few features similar to those of some interacting Type Ibn and Icn SNe. Additionally, SN 2021ocs showed a blue color, (g - r) ≲ -0.5 mag, after the peak and up to late phases, atypical for a Type Ic SN. Together with the nebular spectrum, this suggests that SN 2021ocs underwent late-time interaction with an H/He-poor circumstellar medium (CSM) resulting from the pre-SN progenitor mass loss during its final ~1000 days. The strong O and Mg lines and the absence of strong C and He lines suggest that the progenitor star's O-Mg layer is exposed, which places SN 2021ocs as the most extreme case of a massive progenitor star's envelope stripping in interacting SNe, followed by Type Icn (stripped C-O layer) and Ibn (stripped He-rich layer) SNe. This is the first time such a case is reported in the literature. The SN 2021ocs emphasizes the importance of late-time spectroscopy of SNe, even for those classified as normal events, to reveal the inner ejecta and progenitor star's CSM and mass loss. *Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO program 108.2282.001.

Keywords: Ejecta, Core-collapse supernovae, Late stellar evolution, Massive stars, Circumstellar matter, Wolf-Rayet stars, Supernovae
White Dwarf-Red Giant Star Binaries as Type Ia Supernova Progenitors: With and without Magnetic Confinement. Various white-dwarf (WD) binary scenarios have been proposed trying to understand the nature and the diversity of type Ia supernovae (SNe Ia). In this work, we study the evolution of carbon-oxygen WD-red giant (RG) binaries (including the role of magnetic confinement) as possible SN Ia progenitors (the so-called symbiotic progenitor channel). Using the MESA stellar evolution code, we calculate the time dependence of the structure of the RG star, the wind mass loss, the Roche lobe-overflow mass-transfer rate, the polar mass-accretion rate (in the case of magnetic confinement), and the orbital and angular-momentum evolution. We consider cases where the WD is nonmagnetic and cases where the magnetic field is strong enough to force accretion onto the two small polar caps of the WD. Confined accretion onto a small area allows for more efficient hydrogen burning, potentially suppressing nova outbursts. This makes it easier for the WD to grow in mass toward the Chandrasekhar-mass limit and explode as a SN Ia. With magnetic confinement, the initial parameter space of the symbiotic channel for SNe Ia is shifted toward shorter orbital periods and lower donor masses compared to the case without magnetic confinement. Searches for low-mass He WDs or relatively low-mass giants with partially stripped envelopes that survived the supernova explosion and are found in SN remnants will provide crucial insights for our understanding of the contribution of this symbiotic channel.

Keywords: Close binary stars, White dwarf stars, Type Ia supernovae, Red giant stars, Magnetic fields
Evidence of a Nonorthogonal X-line in Guide-field Magnetic Reconnection. We present observations that suggest the X-line of guide-field magnetic reconnection is not necessarily orthogonal to the plane in which magnetic reconnection is occurring. The plane of magnetic reconnection is often referred to as the L-N plane, where L is the direction of the reversing and reconnecting magnetic field and N is normal to the current sheet. The X-line is often assumed to be orthogonal to the L-N plane (defined as the M-direction) in the majority of theoretical studies and numerical simulations. The four-satellite Magnetospheric Multiscale (MMS) mission, however, observes a guide-field magnetic reconnection event in Earth's magnetotail in which the X-line may be oblique to the L-N plane. This finding is somewhat opportune as two of the MMS satellites at the same N location report nearly identical observations with no significant time delays in the electron diffusion region (EDR) even though they have substantial separation in L. A minimum directional derivative analysis suggests that the X-line is between 40° and 60° from M, adding support that the X-line is oblique. Furthermore, the measured ion velocity is inconsistent with the apparent motion of the MMS spacecraft in the L-direction through the EDR, which can be resolved if one assumes a shear in the L-N plane and motion in the M-direction. A nonorthogonal X-line, if somewhat common, would call for revisiting theory and simulations of guide-field magnetic reconnection, reexamination of how the reconnection electric field is supported in the EDR, and reconsidering the large-scale geometry of the X-line.

Keywords: Space plasmas, Plasma physics, Planetary magnetospheres, Plasma astrophysics
Can 1D Radiative-equilibrium Models of Faculae Be Used for Calculating Contamination of Transmission Spectra?. The reliable characterization of planetary atmospheres with transmission spectroscopy requires realistic modeling of stellar magnetic features, since features that are attributable to an exoplanet atmosphere could instead stem from the host star's magnetic activity. Current retrieval algorithms for analyzing transmission spectra rely on intensity contrasts of magnetic features from 1D radiative-convective models. However, magnetic features, especially faculae, are not fully captured by such simplified models. Here we investigate how well such 1D models can reproduce 3D facular contrasts, taking a G2V star as an example. We employ the well-established radiative magnetohydrodynamic code MURaM to obtain three-dimensional simulations of the magnetoconvection and photosphere harboring a local small-scale dynamo. Simulations without additional vertical magnetic fields are taken to describe the quiet solar regions, while simulations with initially 100 G, 200 G, and 300 G vertical magnetic fields are used to represent facular regions of different magnetic flux density. Subsequently, the spectra emergent from the MURaM cubes are calculated with the MPS-ATLAS radiative transfer code. We find that the wavelength dependence of facular contrast from 1D radiative-convective models cannot reproduce facular contrasts obtained from 3D modeling. This has far-reaching consequences for exoplanet characterization using transmission spectroscopy, where accurate knowledge of the host star is essential for unbiased inferences of the planetary atmospheric properties.

Keywords: Exoplanet atmospheric composition , Radiative magnetohydrodynamics, Solar faculae, Solar physics, Solar active regions, Exoplanet atmospheres
GOALS-JWST: Tracing AGN Feedback on the Star-forming Interstellar Medium in NGC 7469. We present James Webb Space Telescope (JWST) Mid-Infrared Instrument (MIRI) integral-field spectroscopy of the nearby merging, luminous infrared galaxy, NGC 7469. This galaxy hosts a Seyfert type-1.5 nucleus, a highly ionized outflow, and a bright, circumnuclear star-forming ring, making it an ideal target to study active galactic nucleus (AGN) feedback in the local universe. We take advantage of the high spatial/spectral resolution of JWST/MIRI to isolate the star-forming regions surrounding the central active nucleus and study the properties of the dust and warm molecular gas on ~100 pc scales. The starburst ring exhibits prominent polycyclic aromatic hydrocarbon (PAH) emission, with grain sizes and ionization states varying by only ~30%, and a total star formation rate of 10-30 M ⊙ yr-1 derived from fine structure and recombination emission lines. Using pure rotational lines of H2 we detect 1.2 × 107 M ⊙ of warm molecular gas at a temperature higher than 200 K in the ring. All PAH bands get significantly weaker toward the central source, where larger and possibly more ionized grains dominate the emission, likely the result of the ionizing radiation and/or the fast wind emerging from the AGN. The small grains and warm molecular gas in the bright regions of the ring however display properties consistent with normal star-forming regions. These observations highlight the power of JWST to probe the inner regions of dusty, rapidly evolving galaxies for signatures of feedback and inform models that seek to explain the coevolution of supermassive black holes and their hosts.

Keywords: Starburst galaxies, Polycyclic aromatic hydrocarbons, Seyfert galaxies, Active galactic nuclei, Luminous infrared galaxies