adsabs/SciX_UAT_keywords huggingface dataset:
Near the Edge of the Atira Orbital Realm: Short-term Dynamical Evolution of 2020 HA10 and 2020 OV1

Atiras or Interior Earth Objects (IEOs) have their orbits contained entirely within the orbit of Earth. The first IEO, 1998 DK36, was found in 1998; out of the 23 known Atiras, 15 have been discovered during the last decade. Here, we provide a preliminary assessment of the current dynamical status and short-term orbital evolution of 2020 HA10 and 2020 OV1, two recently discovered Atiras. Our calculations indicate that 2020 HA10 periodically switches between the Aten and Atira orbital realms, and although it is almost certainly a present-day Atira, it spends most of the time following Aten-type orbits. In contrast, 2020 OV1 is well entrenched within the Atira orbital realm, but it might have arrived there relatively recently.

Keywords: asteroids; solar system
Allesfitter: Flexible Star and Exoplanet Inference from Photometry and Radial Velocity

We present allesfitter, a public and open-source Python software for flexible and robust inference of stars and exoplanets given photometric and radial velocity data. Allesfitter offers a rich selection of orbital and transit/eclipse models, accommodating multiple exoplanets, multistar systems, transit-timing variations, phase curves, stellar variability, starspots, stellar flares, and various systematic noise models, including Gaussian processes. It features both parameter estimation and Bayesian model selection, allowing either a Markov Chain Monte Carlo or Nested Sampling fit to be easily run. For novice users, a graphical user interface allows all input and perform analyses to be specified; for Python users, all modules can be readily imported into any existing script. Allesfitter also produces publication-ready tables, LaTeX commands, and figures. The software is publicly available (https://github.com/MNGuenther/allesfitter), pip-installable (pip install allesfitter), and well documented (www.allesfitter.com). Finally, we demonstrate the software's capabilities in several examples and provide updates to the literature where possible for Pi Mensae, TOI-216, WASP-18, KOI-1003, and GJ 1243.

Keywords: exoplanets; binary stars; stellar flares; bayesian statistics; astronomy software; starspots; astronomy data modeling
Can Supernovae Quench Star Formation in High-z Galaxies?

JWST is providing a unique opportunity to directly study the feedback processes regulating star formation (SF) in early galaxies. The two z > 5 quiescent systems (JADES-GS-z7-01-QU and MACS0417-z5BBG) detected so far show a recent starburst after which SF is suppressed. To clarify whether such quenching is due to supernova (SN) feedback, we have developed a minimal physical model. We derive a condition on the minimum star formation rate, ${\mathrm{SFR}}_{\min }$ , lasting for a time interval Δt b , required to quench SF in a galaxy at redshift z, with gas metallicity Z, and hosted by a halo of mass M h . We find that lower (z, Z, M h ) systems are more easily quenched. We then apply the condition to JADES-GS-z7-01-QU (z = 7.3, M ⋆ = 108.6 M ⊙) and MACS0417-z5BBG (z = 5.2, M ⋆ = 107.6 M ⊙) and find that SN feedback largely fails to reproduce the observed quenched SF history. Alternatively, we suggest that SF is rapidly suppressed by radiation-driven dusty outflows sustained by the high specific star formation rates (43 and 25 Gyr‑1, respectively) of the two galaxies. Our model provides a simple tool to interpret the SF histories of post-starburst galaxies and unravel quenching mechanisms from incoming JWST data.

Keywords: high-redshift galaxies; galaxy evolution; galaxy quenching; cosmology
Looking for Traces of Nonminimally Coupled Dark Matter in the X-COP Galaxy Clusters Sample

We look for possible evidence of a nonminimal coupling (NMC) between dark matter (DM) and gravity using data from the X-COP compilation of galaxy clusters. We consider a theoretically motivated NMC that may dynamically arise from the collective behavior of the coarse-grained DM field (e.g., via Bose-Einstein condensation) with averaging/coherence length L NMC. In the Newtonian limit, the NMC modifies the Poisson equation by a term ${L}_{\mathrm{NMC}}^{2}{{\rm{\nabla }}}^{2}\rho $ proportional to the Laplacian of the DM density itself. We show that this term, when acting as a perturbation over the standard Navarro-Frenk-White (NFW) profile of cold DM particles, can yield DM halo density profiles capable of correctly fitting galaxy clusters' pressure profiles with an accuracy comparable to and, in some cases, even better than the standard cold DM NFW profile. We also show that the observed relation between the NMC length scale and the virial mass found in Gandolfi et al. for late-type galaxies is consistent with the relation we find in the current work, suggesting that the previously determined power-law scaling law holds up to galaxy cluster mass scales.

Keywords: cold dark matter; galaxy clusters; dark matter; non-standard theories of gravity; cosmology
Deuterated Polycyclic Aromatic Hydrocarbons in the Interstellar Medium: The Aliphatic C-D Band Strengths

Deuterium (D) was exclusively generated in the Big Bang, and the standard Big Bang nucleosynthesis (BBN) model predicts a primordial abundance of D/H ≈ 26 parts per million (ppm). As the Galaxy evolves, D/H gradually decreases because of astration. The Galactic chemical evolution (GCE) model predicts a present-day abundance of D/H ≳ 20 ppm. However, observations of the local interstellar medium have revealed that the gas-phase interstellar D/H varies considerably from one region to another and has a median abundance of D/H ≈ 13 ppm, substantially lower than predicted from the BBN and GCE models. It has been suggested that the missing D atoms of D/H ≈ 7 ppm could have been locked up in deuterated polycyclic aromatic hydrocarbon (PAH) molecules. However, we have previously demonstrated that PAHs with aromatic C-D units are insufficient to account for the missing D. Here we explore if PAHs with aliphatic C-D units could be a reservoir of D. We perform quantum chemical computations of the vibrational spectra of superdeuterated PAHs (in which one D and one H share one C atom) and PAHs to which a D-substituted methyl group is attached, and derive the band strengths of the aliphatic C-D stretch (A 4.65). By applying the computationally derived A 4.65 to the observed aliphatic C-D emission at ~4.6-4.8 μm, we find that PAHs with aliphatic C-D units could have tied up a substantial amount of D/H and marginally account for the missing D. The possible routes for generating PAHs with aliphatic C-D units are also discussed.

Keywords: polycyclic aromatic hydrocarbons; interstellar line emission; line intensities; astrochemistry; interstellar molecules
Modeling Solar Oscillation Power Spectra. III. Spatiotemporal Spectra of Solar Granulation Velocity Field as Seen in HMI Velocity Measurements

We suggest a physically motivated model of the uncorrelated background, which can be used to improve the accuracy of helioseismic frequency measurements when the background contributes significantly to the formation of spectral lines of acoustic resonances. The basic assumption of our model is that the correlation length of the convective motions is small compared with the horizontal wavelength R ⊙/ℓ of the observations, where ℓ is the degree of the spherical harmonic Y ℓ m (θ, φ). When applied to solar power spectra at frequencies below acoustic resonances, the model reveals a distinct sensitivity to solar rotation: advection of the convective velocity pattern brings spatial correlations in the apparent stochastic velocity field (temporal correlations in the corotating frame induce spatial correlations in the inertial frame). The induced spatiotemporal correlations manifest themselves as an antisymmetric component in the dependence of the convective noise power on azimuthal order m, which allows us to address the solar differential rotation. With 360 days of data obtained by the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory, we measure three components of the rotation rate as a function of latitude using only ℓ = 300. This result indicates that the model suggests a new way of measuring solar subsurface rotation. This approach can complement traditional measurements based on correlation tracking.

Keywords: solar physics
NGC 1605 is not a Binary Cluster

The open star cluster NGC 1605 has recently been reported to in fact consist of two clusters (one intermediate-aged and one old) that merged via a flyby capture. Here we show that Gaia data do not support this scenario. We also report the serendipitous discovery of a new open cluster, Can Batlló 1, with a similar age and distance.

Keywords: open star clusters; astrometry; milky way evolution; astrostatistics; clustering
Detection of Coherent Pulsation Modes in the Strongly Magnetic Of?p Star NGC 1624-2 using TESS Observation

High-cadence Transiting Exoplanet Survey Satellite (TESS) observations are promising for studies of short-term pulsational variability in magnetic O stars, which usually have long rotation periods of the order of months or years. The Of?p star NGC 1624-2 is of special interest as it possesses the strongest magnetic field measured among O stars, together with a giant magnetosphere. We detect three significant low-frequency peaks in TESS 2 minute cadence data, probably corresponding to coherent g mode pulsations. At present, this is the only magnetic O star for which pulsational variability is detected.

Keywords: stellar pulsations; variable stars; magnetic stars; space observatories
Infrared Galaxies Detected by the Atacama Cosmology Telescope

We report on 167 infrared (IR) galaxies selected by AKARI and IRAS and detected in the Atacama Cosmology Telescope (ACT) Data Release 5 (DR5) sky maps at the 98, 150, and 220 GHz frequency bands. Of these detections, 134 (80%) of the millimeter counterparts are first-time identifications with ACT. We expand the previous ACT extragalactic source catalogs, by including new 98 GHz detections and measurements from ACT DR5. We also report flux density measurements at the 98, 150, and 220 GHz frequency bands. We compute α 98-150, α 98-220, and α 150-220 millimeter-wave spectral indices and far-IR to millimeter-wave spectral indices between 90 μm and 98, 150, and 220 GHz. We specify the galaxy type, based on α 150-220. We combine publicly available multiwavelength data-including ultraviolet, optical, near-IR, mid-IR, far-IR, and the millimeter measurements obtained in this work-and perform spectral energy distribution (SED) fitting with CIGALE. With the radio emission decomposition advantage of CIGALE V2022.0, we identify the origins of the millimeter emissions for 69 galaxies in our sample. Our analysis also shows that millimeter data alone indicates the need for a radio synchrotron component in the SEDs that are produced by active galactic nuclei (AGNs) and/or star formation. We present SEDs and measured physical properties of these galaxies, such as the dust luminosity, AGN luminosity, the total IR luminosity, and the ratio of the IR and radio luminosity. We quantify the relationships between the total IR luminosity and the millimeter-band luminosities, which can be used in the absence of SED analysis.

Keywords: infrared galaxies; millimeter astronomy; spectral energy distribution; spectral index; active galactic nuclei
Multiwavelength Polarimetry of the Filamentary Cloud IC 5146. II. Magnetic Field Structures

The IC 5146 cloud is a nearby star-forming region in Cygnus, consisting of molecular gas filaments in a variety of evolutionary stages. We used optical and near-infrared polarization data toward the IC 5146 cloud, reported in the first paper of this series, to reveal the magnetic fields in this cloud. Using the newly released Gaia data, we found that the IC 5146 cloud may contain two separate clouds: a first cloud, including the densest main filament at a distance of ∼600 pc, and a second cloud, associated with the Cocoon Nebula at a distance of ∼800 pc. The spatially averaged H-band polarization map revealed a well-ordered magnetic field morphology, with the polarization segments perpendicular to the main filament but parallel to the nearby subfilaments, consistent with models assuming that the magnetic field is regulating cloud evolution. We estimated the magnetic field strength using the Davis-Chandrasekhar-Fermi method and found that the magnetic field strength scales with volume density with a power-law index of ∼0.5 in the density range from {N}{{{H}}2}∼ 10 to 3000 cm-3, which indicates an anisotropic cloud contraction with a preferred direction along the magnetic field. In addition, the mass-to-flux ratio of the cloud gradually changes from subcritical to supercritical from the cloud envelope to the deep regions. These features are consistent with strong magnetic field star formation models and suggest that the magnetic field is important in regulating the evolution of the IC 5146 cloud.

Keywords: interstellar magnetic fields; molecular clouds; collapsing clouds; interstellar filaments; starlight polarization
PAH Spectroscopy from 1 to 5 μm

The PAH model predicts many weak emission features in the 1-5 μm region that can resolve significant questions that it has faced since its inception in the mid-80s. These features contain fundamental information about the PAH population that is inaccessible via the much stronger PAH bands in the 5-20 μm region. Apart from the 3.3 μm band and plateau, PAH spectroscopy across most of the 1-5 μm region has been unexplored due to its low intrinsic intensity. ISO and Akari covered some of this wavelength range, but lacked the combined sensitivity and resolution to measure the predicted bands with sufficient fidelity. The spectroscopic capabilities of the NIRSpec instrument on board JWST will make it possible to measure and fully characterize many of the PAH features expected in this region. These include the fundamental, overtone and combination C-D and C ≅ N stretching bands of deuterated PAHs, cyano-PAHs (PAH-C≅N), and the overtones and combinations of the strong PAH bands that dominate the 5-20 μm region. These bands will reveal the amount of D tied up in PAHs, the PAH D/H ratio, the D distribution between PAH aliphatic and aromatic subcomponents, and delineate key stages in PAH formation and evolution on an object-by-object basis and within extended objects. If cyano-PAHs are present, these bands will also reveal the amount of cyano groups tied up in PAHs, determine the N/C ratio within that PAH subset, and distinguish between the bands near 4.5 μm that arise from CD versus C ≅ N.

Keywords: polycyclic aromatic hydrocarbons; infrared astronomy; molecular spectroscopy; astrochemistry
The Panchromatic Hubble Andromeda Treasury: Triangulum Extended Region (PHATTER). V. The Structure of M33 in Resolved Stellar Populations

We present a detailed analysis of the structure of the Local Group flocculent spiral galaxy M33, as measured using the Panchromatic Hubble Andromeda Treasury Triangulum Extended Region (PHATTER) survey. Leveraging the multiwavelength coverage of PHATTER, we find that the oldest populations are dominated by a smooth exponential disk with two distinct spiral arms and a classical central bar-completely distinct from what is seen in broadband optical imaging, and the first-ever confirmation of a bar in M33. We estimate a bar extent of ~1 kpc. The two spiral arms are asymmetric in orientation and strength, and likely represent the innermost impact of the recent tidal interaction responsible for M33's warp at larger scales. The flocculent multiarmed morphology for which M33 is known is only visible in the young upper main-sequence population, which closely tracks the morphology of the interstellar medium. We investigate the stability of M33's disk, finding Q ~ 1 over the majority of the disk. We fit multiple components to the old stellar density distribution and find that, when considering recent stellar kinematics, M33's bulk structure favors the inclusion of an accreted halo component, modeled as a broken power law. The best-fit halo has an outer power-law index of -3 and accurately describes observational evidence of M33's stellar halo from both resolved stellar spectroscopy in the disk and its stellar populations at large radius. Integrating this profile yields a total halo stellar mass of ~5 × 108 M ⊙, for a stellar halo mass fraction of 16%, most of which resides in the innermost 2.5 kpc.

Keywords: galaxy structure; local group; triangulum galaxy; stellar populations; barred spiral galaxies; hst photometry
MOSEL and IllustrisTNG: Massive Extended Galaxies at z = 2 Quench Later Than Normal-size Galaxies

Using the TNG100 (100 Mpc)3 simulation of the IllustrisTNG project, we demonstrate a strong connection between the onset of star formation quenching and the stellar size of galaxies. We do so by tracking the evolutionary history of extended and normal-size galaxies selected at z = 2 with $\mathrm{log}({M}_{* }/{\text{}}{M}_{\odot })$ $=\,10.2\mbox{--}11$ and stellar-half-mass-radii above and within 1σ of the stellar size-stellar mass relation, respectively. We match the stellar mass and star formation rate distributions of the two populations. By z = 1, only 36% of the extended massive galaxies have quenched, in contrast to a quenched fraction of 69% for the normal-size massive galaxies. We find that normal-size massive galaxies build up their central stellar mass without a significant increase in their stellar size between $z=2\mbox{--}4$ , whereas the stellar size of the extended massive galaxies almost doubles in the same time. In IllustrisTNG, lower black hole masses and weaker kinetic-mode feedback appears to be responsible for the delayed quenching of star formation in the extended massive galaxies. We show that relatively gas-poor mergers may be responsible for the lower central stellar density and weaker supermassive black hole feedback in the extended massive galaxies.

Keywords: galaxies; galaxy evolution; hydrodynamical simulations; galaxy formation
Ultradiffuse Galaxies in the Coma Cluster: Probing Their Origin and AGN Occupation Fraction

Ultradiffuse galaxies (UDGs) exhibit low surface brightness, but their optical extent is comparable to that of Milky Way-type galaxies. In this work, we utilize Chandra X-ray observations of 404 UDGs in the Coma cluster and address two crucial goals. First, we constrain the formation scenario of UDGs by probing the X-ray emission originating from diffuse gas and from the population of unresolved low-mass X-ray binaries (LMXBs) residing in globular clusters (GCs). It is expected that both the luminosity of the hot gas and the number of GCs, and hence the luminosity from GC-LMXBs, are proportional to the total mass of the dark matter halo. We do not detect statistically significant emission from the hot gas or from GC-LMXBs. The upper limits on the X-ray luminosities suggest that the bulk of the UDGs reside in low-mass dark matter halos, implying that they are genuine dwarf galaxies. This conclusion agrees with our previous results obtained for isolated UDGs, arguing that UDGs are a homogeneous population of galaxies. Second, we constrain the AGN occupation fraction of UDGs, i.e., the fraction of UDGs that are occupied by an active galactic nucleus, for the first time. To this end, we cross-correlate the position of detected X-ray sources in the Coma cluster with the position of UDGs. We identify two UDGs that have a luminous X-ray source at 3"0 and 3"2 from their center, which could be off-center AGNs. However, Monte Carlo simulations suggest that one of these sources could be the result of spatial coincidence with a background AGN. Therefore, we place an upper limit of ≲0.5% on the AGN occupation fraction of UDGs.

Keywords: x-ray photometry; coma cluster; dwarf galaxies; galaxy evolution; low surface brightness galaxies
Exploring the Solar Wind from Its Source on the Corona into the Inner Heliosphere during the First Solar Orbiter-Parker Solar Probe Quadrature

This Letter addresses the first Solar Orbiter (SO)-Parker Solar Probe (PSP) quadrature, occurring on 2021 January 18 to investigate the evolution of solar wind from the extended corona to the inner heliosphere. Assuming ballistic propagation, the same plasma volume observed remotely in the corona at altitudes between 3.5 and 6.3 solar radii above the solar limb with the Metis coronagraph on SO can be tracked to PSP, orbiting at 0.1 au, thus allowing the local properties of the solar wind to be linked to the coronal source region from where it originated. Thanks to the close approach of PSP to the Sun and the simultaneous Metis observation of the solar corona, the flow-aligned magnetic field and the bulk kinetic energy flux density can be empirically inferred along the coronal current sheet with an unprecedented accuracy, allowing in particular estimation of the Alfvén radius at 8.7 solar radii during the time of this event. This is thus the very first study of the same solar wind plasma as it expands from the sub-Alfvénic solar corona to just above the Alfvén surface.

Keywords: magnetohydrodynamics; space plasmas; interplanetary turbulence; solar corona; heliosphere; solar wind
New Resonance Scattering Model in AtomDB: Application to Line Suppression in Galaxy Clusters and Elliptical Galaxies

In this paper, we present the simple, one-step, self-consistent, and fast resonance scattering model rsapec based on the AtomDB database. This model can be used as an alternative to the commonly used APEC model for fitting X-ray spectra with optically thick lines. The current model is intended, in general, for verifying the presence of the effect and for spectral modeling of galaxy clusters and elliptical galaxies under applicable assumptions. We test rsapec to derive the line suppression in the elliptical galaxy NGC 4636 and the Perseus cluster of galaxies and obtain resonance suppressions of ~1.24 and ~1.30, respectively.

Keywords: high resolution spectroscopy; galaxy clusters; elliptical galaxies; publicly available software
Cool, Luminous, and Highly Variable Stars in the Magellanic Clouds from ASAS-SN: Implications for Thorne-Żytkow Objects and Super-asymptotic Giant Branch Stars

Stars with unusual properties can provide a wealth of information about rare stages of stellar evolution and exotic physics. However, determining the true nature of peculiar stars is often difficult. In this work, we conduct a systematic search for cool and luminous stars in the Magellanic Clouds with extreme variability, motivated by the properties of the unusual Small Magellanic Cloud star and Thorne-Żytkow Object (TŻO) candidate HV 2112. Using light curves from ASAS-SN, we identify 38 stars with surface temperatures T < 4800 K, luminosities $\mathrm{log}$ (L/L⊙) > 4.3, variability periods >400 days, and variability amplitudes ΔV > 2.5 mag. Eleven of these stars possess the distinctive double-peaked light-curve morphology of HV 2112. We use the pulsation properties and derived occurrence rates for these 12 objects to constrain their nature. From comparisons to stellar populations and models, we find that one star may be a red supergiant with large-amplitude pulsations. For the other 11 stars, we derive current masses of ∼5-10 M⊙, below the theoretical minimum mass of ∼15 M⊙ for TŻOs to be stable, casting doubt on this interpretation. Instead, we find that the temperatures, luminosities, mass-loss rates (MLRs), and periods of these stars are consistent with predictions for super-asymptotic giant branch (s-AGB) stars that have begun carbon burning but have not reached the superwind phase. We infer lifetimes in this phase of ∼(1-7) × 104 yr, also consistent with an s-AGB interpretation. If confirmed, these objects would represent the first identified population of s-AGB stars, illuminating the transition between low- and high-mass stellar evolution.

Keywords: massive stars; asymptotic giant branch stars; variable stars; chemically peculiar stars; light curves; photometry