Sazuna/UAT_keywords huggingface dataset:
GOALS-JWST: NIRCam and MIRI Imaging of the Circumnuclear Starburst Ring in NGC 7469. We present James Webb Space Telescope (JWST) imaging of NGC 7469 with the Near-Infrared Camera and the Mid-InfraRed Instrument. NGC 7469 is a nearby, z = 0.01627, luminous infrared galaxy that hosts both a Seyfert Type-1.5 nucleus and a circumnuclear starburst ring with a radius of ~0.5 kpc. The new near-infrared (NIR) JWST imaging reveals 66 star-forming regions, 37 of which were not detected by Hubble Space Telescope (HST) observations. Twenty-eight of the 37 sources have very red NIR colors that indicate obscurations up to A v ~ 7 and a contribution of at least 25% from hot dust emission to the 4.4 μm band. Their NIR colors are also consistent with young (&lt;5 Myr) stellar populations and more than half of them are coincident with the mid-infrared (MIR) emission peaks. These younger, dusty star-forming regions account for ~6% and ~17% of the total 1.5 and 4.4 μm luminosity of the starburst ring, respectively. Thanks to JWST, we find a significant number of young dusty sources that were previously unseen due to dust extinction. The newly identified 28 young sources are a significant increase compared to the number of HST-detected young sources (4-5). This makes the total percentage of the young population rise from ~15% to 48%. These results illustrate the effectiveness of JWST in identifying and characterizing previously hidden star formation in the densest star-forming environments around active galactic nuclei (AGN).

Keywords: Infrared astronomy, Star forming regions, Infrared sources, Luminous infrared galaxies
GOALS-JWST: Mid-infrared Spectroscopy of the Nucleus of NGC 7469. We present mid-infrared spectroscopic observations of the nucleus of the nearby Seyfert galaxy NGC 7469 taken with the MIRI instrument on the James Webb Space Telescope (JWST) as part of Directors Discretionary Time Early Release Science program 1328. The high-resolution nuclear spectrum contains 19 emission lines covering a wide range of ionization. The high-ionization lines show broad, blueshifted emission reaching velocities up to 1700 km s-1 and FWHM ranging from ~500 to 1100 km s-1. The width of the broad emission and the broad-to-narrow line flux ratios correlate with ionization potential. The results suggest a decelerating, stratified, AGN-driven outflow emerging from the nucleus. The estimated mass outflow rate is 1-2 orders of magnitude larger than the current black hole accretion rate needed to power the AGN. Eight pure rotational H2 emission lines are detected with intrinsic widths ranging from FWHM ~125 to 330 km s-1. We estimate a total mass of warm H2 gas of ~1.2 × 107 M ⊙ in the central 100 pc. The PAH features are extremely weak in the nuclear spectrum, but a 6.2 μm PAH feature with an equivalent width of ~0.07 μm and a flux of 2.7 × 10-17 W m-2 is detected. The spectrum is steeply rising in the mid-infrared, with a silicate strength of ~0.02, significantly smaller than seen in most PG QSOs but comparable to other Seyfert 1s. These early MIRI mid-infrared IFU data highlight the power of JWST to probe the multiphase interstellar media surrounding actively accreting supermassive black holes.

Keywords: Starburst galaxies, Active galaxies, Infrared galaxies
A Need to Revise Stellar Opacities from Asteroseismology of δ Scuti Stars. We construct seismic models of the four double-mode radial δ Scuti stars adopting opacities from three databases: OPAL, OP, and OPLIB. The aim is to find the models that fit the observed frequencies of the two radial modes and have the effective temperature and luminosity consistent with the observed values. Using the Bayesian analysis based on Monte Carlo simulations, we obtain that only the OPAL seismic models are caught within the observed error box in the H-R diagram. Seismic models computed with the OP and OPLIB data are much cooler and less luminous. By including the relative amplitude of the bolometric flux variations (the so-called parameter f) into these simulations, we constrain the efficiency of convection in the envelopes, described by the mixing-length parameter α MLT. We get α MLT ≈ 0.5 for BP Pegasi, AE Ursa Majoris, and RV Arietis (Population I stars) and α MLT ≈ 1.0 for SX Phoenicis (Population II star). For all the stars, overshooting from the convective core seems inefficient. A similar effect of opacity should occur also for classical Cepheids or RR Lyr stars that are used as standard candles to measure the universe.

Keywords: Delta Scuti variable stars, Stellar pulsations, Atomic data, Asteroseismology, Stellar evolution
Constraints on the Hosts of UHECR Accelerators. Interactions of ultra-high-energy cosmic rays (UHECRs) in the surroundings of their accelerators can naturally explain the observed spectrum and composition of UHECRs, including the abundance of protons below the ankle. Here we show that astrophysical properties of the UHECR source environment such as the temperature, size, and magnetic field can be constrained by UHECR and neutrino data. Applying this to candidate sources with a simple structure shows that starburst galaxies are consistent with these constraints, but galaxy clusters are in tension with them. For multicomponent systems like active galactic nuclei and gamma-ray bursts, the results are indicative, but a customized analysis is needed for definitive conclusions.

Keywords: Cosmic ray sources, Ultra-high-energy cosmic radiation
Timing Analysis of the 2022 Outburst of the Accreting Millisecond X-Ray Pulsar SAX J1808.4-3658: Hints of an Orbital Shrinking. We present a pulse timing analysis of NICER observations of the accreting millisecond X-ray pulsar SAX J1808.4-3658 during the outburst that started on 2022 August 19. Similar to previous outbursts, after decaying from a peak luminosity of ≃1 × 1036 erg s-1 in about a week, the pulsar entered a ~1 month long reflaring stage. Comparison of the average pulsar spin frequency during the outburst with those previously measured confirmed the long-term spin derivative of ${\dot{\nu }}_{\mathrm{SD}}=-(1.15\,\pm \,0.06)\times \,{10}^{-15}$ Hz s-1, compatible with the spin-down torque of a ≈1026 G cm3 rotating magnetic dipole. For the first time in the last twenty years, the orbital phase evolution shows evidence for a decrease of the orbital period. The long-term behavior of the orbit is dominated by an ~11 s modulation of the orbital phase epoch consistent with a ~21 yr period. We discuss the observed evolution in terms of a coupling between the orbit and variations in the mass quadrupole of the companion star.

Keywords: Stellar accretion disks, Neutron stars, Millisecond pulsars
MHD Simulation of a Solar Eruption from Active Region 11429 Driven by a Photospheric Velocity Field. Data-driven simulation is becoming an important approach for realistically characterizing the configuration and evolution of solar active regions, revealing the onset mechanism of solar eruption events, and hopefully achieving the goal of accurate space weather forecasting, which is beyond the scope of any existing theoretical modeling. Here we performed a full 3D MHD simulation using the data-driven approach and followed the whole evolution process from the quasi-static phase to eruption successfully for solar active region (AR) NOAA 11429. The MHD system was driven at the bottom boundary by a photospheric velocity field, which is derived by the DAVE4VM method from the observed vector magnetograms. The simulation shows that a magnetic flux rope was generated by a persistent photospheric flow before the flare onset and then triggered to erupt by torus instability. Our simulation demonstrates a high degree of consistency with observations in the preeruption magnetic structure, the timescale of the quasi-static stage, the pattern of flare ribbons, as well as the time evolution of the magnetic energy injection and total unsigned magnetic flux. We further found that an eruption can also be initiated in the simulation driven by only the horizontal components of the photospheric flow, but a comparison of the different simulations indicates that the vertical flow at the bottom boundary is necessary for reproducing more realistically these observed features, emphasizing the importance of flux emergence during the development of this AR.

Keywords: Solar active region magnetic fields, Magnetohydrodynamics, Solar flares, Solar coronal mass ejections, Magnetohydrodynamical simulations
Morpheus Reveals Distant Disk Galaxy Morphologies with JWST: The First AI/ML Analysis of JWST Images. The dramatic first images with JWST demonstrated its power to provide unprecedented spatial detail for galaxies in the high-redshift universe. Here, we leverage the resolution and depth of the JWST Cosmic Evolution Early Release Science Survey data in the Extended Groth Strip to perform pixel-level morphological classifications of galaxies in JWST F150W imaging using the Morpheus deep-learning framework for astronomical image analysis. By cross-referencing with existing photometric redshift catalogs from the Hubble Space Telescope (HST) CANDELS survey, we show that JWST images indicate the emergence of disk morphologies before z ~ 2 and with candidates appearing as early as z ~ 5. By modeling the light profile of each object and accounting for the JWST point-spread function, we find the high-redshift disk candidates have exponential surface brightness profiles with an average Sérsic index &lt;n&gt; = 1.04 and &gt;90% displaying "disky" profiles (n &lt; 2). Comparing with prior Morpheus classifications in CANDELS we find that a plurality of JWST disk galaxy candidates were previously classified as compact based on the shallower HST imagery, indicating that the improved optical quality and depth of the JWST helps to reveal disk morphologies that were hiding in the noise. We discuss the implications of these early disk candidates on theories for cosmological disk galaxy formation.

Keywords: Disk galaxies, Neural networks, Galaxy classification systems, James Webb Space Telescope, Galaxies
Estimating Molecular Gas Content in Galaxies from Polycyclic Aromatic Hydrocarbon Emission. Emission from polycyclic aromatic hydrocarbons (PAHs), a commonly used indicator of star formation activity in galaxies, also has the potential to serve as an effective empirical tracer of molecular gas. We use a sample of 19 nearby galaxies with spatially resolved mid-infrared Spitzer spectroscopy, multiwavelength optical and mid-infrared imaging, and millimeter interferometric CO(1-0) maps to investigate the feasibility of using PAH emission as an empirical proxy to estimate molecular gas mass. PAH emission correlates strongly with CO emission on subkiloparsec scales over the diverse environments probed by our sample of star-forming galaxies and low-luminosity active galactic nuclei. The tight observed correlation, likely a consequence of photoelectronic heating of the diffuse interstellar gas by the PAHs, permits us to derive an empirical calibration to estimate molecular gas mass from the luminosity of PAH emission that has a total scatter of only ~0.2-0.25 dex. Mid-infrared bands sensitive to PAH emission (e.g., the Spitzer/IRAC4 and WISE/W3 filters) can also be used as a highly effective substitute for this purpose.

Keywords: Interstellar molecules, Interstellar dust, Molecular gas, Polycyclic aromatic hydrocarbons, Interstellar emissions, Star formation, Interstellar medium
RELICS: Small-scale Star Formation in Lensed Galaxies at z = 6-10. Detailed observations of star-forming galaxies at high redshift are critical to understanding the formation and evolution of the earliest galaxies. Gravitational lensing provides an important boost, allowing observations at physical scales unreachable in unlensed galaxies. We present three lensed galaxies from the RELICS survey at z phot = 6-10, including the most highly magnified galaxy at z phot ~ 6 (WHL 0137-zD1, dubbed the Sunrise Arc), the brightest known lensed galaxy at z phot ~ 6 (MACS 0308-zD1), and the only spatially resolved galaxy currently known at z phot ~ 10 (SPT 0615-JD). The Sunrise Arc contains seven star-forming clumps with delensed radii as small as 3 pc, the smallest spatial scales yet observed in a z &gt; 6 galaxy, while SPT 0615-JD contains features measuring a few tens of parsecs. MACS 0308-zD1 contains an r ~ 30 pc clump with a star formation rate (SFR) of ~3 M ⊙ yr-1, giving it an SFR surface density of ΣSFR ~ 103 M ⊙ yr-1 kpc-2. These galaxies provide a unique window into small-scale star formation during the epoch of reionization. They will be excellent targets for future observations with JWST, including one approved program targeting the Sunrise Arc.

Keywords: Young massive clusters, Gravitational lensing, Galaxy evolution
Discussions on the Nature of GLEAM-X J162759.5-523504.3. The nature of the long-period radio transient GLEAM-X J162759.5-523504.3 (hereafter GLEAM-X J1627) is discussed. We try to understand both its radio emission and pulsation in the neutron star scenario as an alternative to the white dwarf model. We think that (1) from the radio emission point of view, GLEAM-X J1627 can be a radio-loud magnetar; (2) from the rotational evolution point of view, GLEAM-X J1627 is unlikely to be an isolated magnetar; (3) the 1091 s period is unlikely to be the precession period; (4) GLEAM-X J1627 may be a radio-loud magnetar spun down by a fallback disk; (5) the pulsar death line is modified due to the presence of a fallback disk or a twisted magnetic field. In both cases, a higher maximum acceleration potential can be obtained. This may explain why GLEAM-X J1627 is still radioactive with such a long pulsation period; and (6) general constraints on the neutron star magnetic field and initial disk mass are given analytically. Possible ways to discriminate between different modelings are also discussed.

Keywords: Magnetars, Radio pulsars, Pulsars
A Framework for Obtaining Accurate Posteriors of Strong Gravitational Lensing Parameters with Flexible Priors and Implicit Likelihoods Using Density Estimation. We report the application of implicit likelihood inference to the prediction of the macroparameters of strong lensing systems with neural networks. This allows us to perform deep-learning analysis of lensing systems within a well-defined Bayesian statistical framework to explicitly impose desired priors on lensing variables, obtain accurate posteriors, and guarantee convergence to the optimal posterior in the limit of perfect performance. We train neural networks to perform a regression task to produce point estimates of lensing parameters. We then interpret these estimates as compressed statistics in our inference setup and model their likelihood function using mixture density networks. We compare our results with those of approximate Bayesian neural networks, discuss their significance, and point to future directions. Based on a test set of 100,000 strong lensing simulations, our amortized model produces accurate posteriors for any arbitrary confidence interval, with a maximum percentage deviation of 1.4% at the 21.8% confidence level, without the need for any added calibration procedure. In total, inferring 100,000 different posteriors takes a day on a single GPU, showing that the method scales well to the thousands of lenses expected to be discovered by upcoming sky surveys.

Keywords: Neural networks, Posterior distribution, Strong gravitational lensing, Convolutional neural networks, Gaussian mixture model, Bayes' Theorem, Computational methods, Gravitational lensing, Confidence interval, Markov chain Monte Carlo, GPU computing, Prior distribution
The Hα and [O III] λ5007 Luminosity Functions of 1.2 &lt; z &lt; 1.9 Emission-line Galaxies from Hubble Space Telescope (HST) Grism Spectroscopy. Euclid and the Roman Space Telescope (Roman) will soon use grism spectroscopy to detect millions of galaxies via their Hα and [O III] λ5007 emission. To better constrain the expected galaxy counts from these instruments, we use a vetted sample of 4239 emission-line galaxies from the 3D Hubble Space Telescope survey to measure the Hα and [O III] λ5007 luminosity functions between 1.16 &lt; z &lt; 1.90; this sample is ~4 times larger than previous studies at this redshift. We find very good agreement with previous measurements for Hα, but for [O III], we predict a higher number of intermediate-luminosity galaxies than from previous works. We find that, for both lines, the characteristic luminosity, ${{ \mathcal L }}_{* }$ , increases monotonically with redshift, and use the Hα luminosity function to calculate the epoch's cosmic star formation rate density. We find that Hα-visible galaxies account for ~81% of the epoch's total star formation rate, and this value changes very little over the 1.16 &lt; z &lt; 1.56 redshift range. Finally, we derive the surface density of galaxies as a function of limiting flux and find that previous predictions for galaxy counts for the Euclid Wide Survey are unchanged, but there may be more [O III] galaxies in the Roman High Latitude Survey than previously estimated.

Keywords: Luminosity function, High-redshift galaxies, Spectral energy distribution, Galaxy evolution
Formation History of HD 106906 and the Vertical Warping of Debris Disks by an External Inclined Companion. HD 106906 is a planetary system that hosts a wide-orbit companion, as well as an eccentric and flat debris disk, which hold important constraints on its formation and subsequent evolution. The recent observations of the companion constrain its orbit to be eccentric and inclined relative to the plane of the debris disk. Here, we show that, in the presence of the inclined companion, the debris disk quickly (≲5 Myr) becomes warped and puffy. This suggests that the current configuration of the system is relatively recent. We explore the possibility that a recent close encounter with a free-floating planet could produce a companion with orbital parameters that agree with observations of HD 106906 b. We find that this scenario is able to recreate the structure of the debris disk while producing a companion in agreement with observation.

Keywords: Orbits, Debris disks, Planetary dynamics, Exoplanets
Statistical Study of the Star Formation Efficiency in Bars: Is Star Formation Suppressed in Gas-rich Bars?. The dependence of the star formation efficiency (SFE) on galactic structures-especially whether the SFE in the bar region is lower than those in other regions-has recently been debated. We report the SFEs of 18 nearby gas-rich massive star-forming barred galaxies with large apparent bar major axes (≧75″). We statistically measure the SFE by distinguishing the center, the bar end, and the bar regions for the first time. The molecular gas surface density is derived from archival CO(1-0) and/or CO(2-1) data by assuming a constant CO-to-H2 conversion factor (α CO), and the star formation rate surface density is derived from a linear combination of far-UV and mid-IR intensities. The angular resolution is 15″, which corresponds to 0.3-1.8 kpc. We find that the ratio of the SFE in the bar to that in the disk was systematically lower than unity (typically 0.6-0.8), which means that the star formation in the bar is systematically suppressed. Our results are inconsistent with similar recent statistical studies, which have reported that the SFE tends to be independent of galactic structures. This inconsistency can be attributed to the differences in the definitions of the bar region, the spatial resolutions, the α CO, and the sample galaxies. Furthermore, we find a negative correlation between the SFE and the velocity width of the CO spectrum, which is consistent with the idea that the large dynamical effects-such as strong shocks, large shears, and fast cloud-cloud collisions caused by the noncircular motion of the bar-result in a low SFE.

Keywords: Molecular gas, Star formation, Interstellar medium, CO line emission, Barred spiral galaxies, Galaxies
Effects of Planetesimal Scattering: Explaining the Observed Offsets from Period Ratios 3:2 and 2:1. The observed deficit and excess of adjacent planet pairs with period ratios narrow and wide of 3:2 and 2:1, the nominal values for the corresponding mean-motion resonances (MMRs), have intrigued many. Previously, using a suite of simulations, Chatterjee &amp; Ford showed that the excess above the 2:1 MMR can be naturally explained if planet pairs, initially trapped in the 2:1 MMR, dynamically interact with nearby planetesimals in a disk. We build on this work by (a) updating the census of discovered planet pairs, (b) extending the study to initially nonresonant as well as resonant planet pairs, (c) using initial planet and orbital properties directly guided by those observed, and (d) extending the initial period ratios to include both 2:1 and 3:2. We find that (1) interactions with planetesimals typically increase the period ratios of both initially resonant and nonresonant planet pairs; (2) starting from an initially flat period ratio distribution for systems across 3:2 and 2:1, these interactions can naturally create the deficits observed narrow of these period ratios; (3) a contribution from initially resonant planet pairs is needed to explain the observed levels of excess wide of 3:2; and (4) a mixture model where about 25% (1%) of planet pairs were initially trapped into 3:2 (2:1) MMRs is favored to explain both the observed deficit and excess of systems across these period ratios. However, up to a few percent of planet pairs are expected to remain in MMR today.

Keywords: Exoplanet dynamics, Exoplanet migration, Orbital resonances, Exoplanets
Generative Models of Multichannel Data from a Single Example-Application to Dust Emission. The quest for primordial B-modes in the cosmic microwave background has emphasized the need for refined models of the Galactic dust foreground. Here we aim at building a realistic statistical model of the multifrequency dust emission from a single example. We introduce a generic methodology relying on microcanonical gradient descent models conditioned by an extended family of wavelet phase harmonic (WPH) statistics. To tackle the multichannel aspect of the data, we define cross-WPH statistics, quantifying non-Gaussian correlations between maps. Our data-driven methodology could apply to various contexts, and we have updated the software PyWPH, on which this work relies, accordingly. Applying this to dust emission maps built from a magnetohydrodynamics simulation, we construct and assess two generative models: (1) a (I, E, B) multi-observable input, and (2) a ${\{{I}_{\nu }\}}_{\nu }$ multifrequency input. The samples exhibit consistent features compared to the original maps. A statistical analysis of model 1 shows that the power spectra, distributions of pixels, and Minkowski functionals are captured to a good extent. We analyze model 2 by fitting the spectral energy distribution (SED) of both the synthetic and original maps with a modified blackbody (MBB) law. The maps are equally well fitted, and a comparison of the MBB parameters shows that our model succeeds in capturing the spatial variations of the SED from the data. Besides the perspectives of this work for dust emission modeling, the introduction of cross-WPH statistics opens a new avenue to characterize non-Gaussian interactions across different maps, which we believe will be fruitful for astrophysics.

Keywords: Interstellar dust, Cosmic microwave background radiation, Astrostatistics