Sazuna/UAT_keywords huggingface dataset:
Secular Spin-Orbit Resonances of Black Hole Binaries in AGN Disks. The spin-orbit misalignment of stellar-mass black hole (sBH) binaries provides important constraints on the formation channels of merging sBHs. Here, we study the role of secular spin-orbit resonance in the evolution of an sBH binary component around a supermassive BH (SMBH) in an AGN disk. We consider the sBH's spin precession due to the J 2 moment introduced by a circum-sBH disk within the warping/breaking radius of the disk. We find that the sBH's spin-orbit misalignment (obliquity) can be excited via spin-orbit resonance between the sBH binary's orbital nodal precession and the sBH spin precession driven by a massive circum-sBH disk. Using an α-disk model with Bondi-Hoyle-Lyttleton accretion, the resonances typically occur for sBH binaries with semimajor axis of 1 au and at a distance of ~1000 au around a 107  M ☉ SMBH. The spin-orbit resonances can lead to high sBH obliquities and a broad distribution of sBH binary spin-spin misalignments. However, we note that the Bondi-Hoyle-Lyttleton accretion is much higher than that of Eddington accretion, which typically results in spin precession being too low to trigger spin-orbit resonances. Thus, secular spin-orbit resonances can be quite rare for sBHs in AGN disks.

Keywords: Orbits, Black hole spin-flip, Gravitational wave sources, Dynamical evolution
Improved Tomographic Binning of 3 × 2 pt Lens Samples: Neural Network Classifiers and Optimal Bin Assignments. Large imaging surveys, such as the Legacy Survey of Space and Time, rely on photometric redshifts and tomographic binning for 3 × 2 pt analyses that combine galaxy clustering and weak lensing. In this paper, we propose a method for optimizing the tomographic binning choice for the lens sample of galaxies. We divide the CosmoDC2 and Buzzard simulated galaxy catalogs into a training set and an application set, where the training set is nonrepresentative in a realistic way, and then estimate photometric redshifts for the application sets. The galaxies are sorted into redshift bins covering equal intervals of redshift or comoving distance, or with an equal number of galaxies in each bin, and we consider a generalized extension of these approaches. We find that bins of equal comoving distance produce the highest dark energy figure of merit of the initial binning choices, but that the choice of bin edges can be further optimized. We then train a neural network classifier to identify galaxies that are either highly likely to have accurate photometric redshift estimates or highly likely to be sorted into the correct redshift bin. The neural network classifier is used to remove poor redshift estimates from the sample, and the results are compared to the case when none of the sample is removed. We find that the neural network classifiers are able to improve the figure of merit by ~13% and are able to recover ~25% of the loss in the figure of merit that occurs when a nonrepresentative training sample is used.

Keywords: Large-scale structure of the universe, Observational cosmology, Dark energy
Measuring the Orbit Drift of Near-Earth Asteroids by the Yarkovsky Effect. The Yarkovsky effect causes the semimajor axis drift of near-Earth asteroids. The drift can be detected by a precise orbit determination process. Using the proposed algorithm, 2233 out of 27,078 near-Earth asteroids are chosen as the initial candidates. Out of these initial candidates, 769 have a measurable Yarkovsky effect with a signal-to-noise ratio (S/N) larger than 1, and 166 have a measurable Yarkovsky effect with an S/N larger than 3. The ratio between retrograde and prograde near-Earth asteroids is plotted with respect to their size. An average ratio of 2 is found for asteroids with an absolute magnitude between 14 and 21. The measurement work is carried out based on orbit determination software developed by the authors that considers a high-precision dynamical model.

Keywords: Near-Earth objects, Astrometry, Orbit determination
Anterograde Collisional Analysis of Solar Wind Ions. Owing to its low density and high temperature, the solar wind frequently exhibits strong departures from local thermodynamic equilibrium, which include distinct temperatures for its constituent ions. Prior studies have found that the ratio of the temperatures of the two most abundant ions-protons (ionized hydrogen) and α-particles (ionized helium)-is strongly correlated with the Coulomb collisional age. These previous studies, though, have been largely limited to using observations from single missions. In contrast, this present study utilizes contemporaneous, in situ observations from two different spacecraft at two different distances from the Sun: the Parker Solar Probe (PSP; r = 0.1-0.3 au) and Wind (r = 1.0 au). Collisional analysis, which incorporates the equations of collisional relaxation and large-scale expansion, was applied to each PSP datum to predict the state of the plasma farther from the Sun at r = 1.0 au. The distribution of these predicted α-proton relative temperatures agrees well with that of values observed by Wind. These results strongly suggest that, outside of the corona, relative ion temperatures are principally affected by Coulomb collisions and that the preferential heating of α-particles is largely limited to the corona.

Keywords: Collision physics, Solar wind, Plasma physics
Shaken or Stirred: The Diffuse Interstellar Medium with Exceptionally High SiO Abundance. Interstellar shocks, a key element of stellar feedback processes, shape the structure of the interstellar medium (ISM) and are essential for the chemistry, thermodynamics, and kinematics of interstellar gas. Powerful, high-velocity shocks are driven by stellar winds, young supernova explosions, more evolved supernova remnants, cloud-cloud collisions, and protostellar outflows, whereas the existence and origin of much-lower-velocity shocks (≲10 km s-1) are not understood. Direct observational evidence for interstellar shocks in diffuse and translucent ISM environments has been especially lacking. We present the most sensitive survey to date of SiO-often considered an unambiguous tracer of interstellar shocks-in absorption, obtained with the Northern Extended Millimeter Array interferometer. We detect SiO in five of eight directions probing diffuse and translucent environments without ongoing star formation. Our results demonstrate that SiO formation in the diffuse ISM (i.e., in the absence of significant star formation and stellar feedback) is more widespread and effective than previously reported. The observed SiO line widths are all ≲4 km s-1, excluding high-velocity shocks as a formation mechanism. Yet, the SiO abundances we detect are mostly 1-2 orders of magnitude higher than those typically assumed in quiescent environments and are often accompanied by other molecular transitions whose column densities cannot be explained with UV-dominated chemical models. Our results challenge the traditional view of SiO production via stellar feedback sources and emphasize the need for observational constraints on the distribution of Si in the gas phase and grain mantles, which are crucial for understanding the physics of grain processing and the diffuse interstellar chemistry.

Keywords: Interstellar line absorption, Shocks, Diffuse molecular clouds
Future Constraints on Dark Matter with Gravitationally Lensed Fast Radio Bursts Detected by BURSTT. Understanding dark matter is one of the most urgent questions in modern physics. A very interesting candidate is primordial black holes (PBHs). For the mass ranges &lt;10-16  M ⊙ and &gt;100 M ⊙, PBHs have been ruled out. However, they are still poorly constrained in the mass range 10-16-100 M ⊙. Fast radio bursts (FRBs) are millisecond flashes of radio light of unknown origin, mostly from outside the Milky Way. Due to their short timescales, gravitationally lensed FRBs, which are yet to be detected, have been proposed as a useful probe for constraining the presence of PBHs in the mass window of &lt;100 M ⊙. Up to now, the most successful project in finding FRBs has been CHIME. Due to its large field of view, CHIME has detected at least 600 FRBs since 2018. However, none of them is confirmed to be gravitationally lensed. Taiwan plans to build a new telescope, the Bustling Universe Radio Survey Telescope in Taiwan (BURSTT), dedicated to detecting FRBs. Its survey area will be 25 times greater than CHIME. BURSTT can localize all of these FRBs through very long baseline interferometry. We estimate the probability to find gravitationally lensed FRBs, based on the scaled redshift distribution from the latest CHIME catalog and the lensing probability function from Munõz et al. BURSTT-2048 can detect ~24 lensed FRBs out of ~1700 FRBs per annum. With BURSTT's ability to detect nanosecond FRBs, we can constrain PBHs to form a part of dark matter down to 10-4 M ⊙.

Keywords: Cosmology, Radio bursts, Extragalactic astronomy, Radio astronomy, Dark matter, Primordial black holes, Radio transient sources
Energetic Electron Pitch-angle Distributions in the Martian Space Environment: Pancake. We perform a statistical investigation of the occurrence rates of energetic electron (100-500 eV) pancake pitch-angle distributions (PADs) in the Martian space environment by utilizing 6 yr of MAVEN data. In the Martian ionosphere, we find the following: (1) at the same altitude in the terminator and night regions, the occurrences rates in the center of the southern magnetic anomaly regions are very low, but at the edges of strong magnetic fields, they increase significantly; (2) the occurrence rates of energetic electron perpendicular anisotropies on the Martian dayside increase with altitude; and (3) some closed magnetic lines in the 10°S-55°S, 30°W-125°W region at 400-800 km altitude gradually become open during the rotation of Mars from duskside to dawnside, while more closed magnetic lines are produced in the 40°S-65°S, 35°E-90°E region. In the Martian induced magnetosphere, we find the following: (1) the high-energy electron perpendicular anisotropy in the magnetosheath is the most significant; (2) the occurrence rates in the southern (Z MSO ≤-1 R M) magnetosheath are higher than those in the northern (Z MSO ≥ 1 R M) magnetosheath; (3) in the region of ∣Z MSO∣ &lt; 0.5 R M, these high-energy electron pancake PADs are mainly concentrated in the magnetosheath region with Y MSO ∈ [-1.4RM, 2R M]; (4) the occurrence rates in the dawnside (Y MSO ≤-1 R M) magnetosheath are higher than those in the duskside (Y MSO ≥ 1 R M) magnetosheath; and (5) in the region of ∣Y MSO∣ &lt; 0.5 R M, the occurrence rates throughout the magnetosheath are very high.

Keywords: Space plasmas, Mars, Planetary magnetospheres, Magnetic fields, Planetary dynamics
Reaction Kinetics of CN + Toluene and Its Implication on the Production of Aromatic Nitriles in the Taurus Molecular Cloud and Titan's Atmosphere. Reactions between cyano radicals and aromatic hydrocarbons are believed to be important pathways for the formation of aromatic nitriles in the interstellar medium (ISM) including those identified in the Taurus molecular cloud (TMC-1). Aromatic nitriles might participate in the formation of polycyclic aromatic nitrogen-containing hydrocarbons (PANHs) in Titan's atmosphere. Here, ab initio kinetic simulations reveal a high efficiency of ~10-10 cm3 s-1 and the competition of the different products of the CN + toluene reaction at 30-1800 K and 10-7-100 atm. In the star-forming region of the TMC-1 environment, the product yields of benzonitrile and tolunitriles for CN reacting with toluene are approximately 17% and 83%, respectively. Detections of the main products, tolunitriles, can serve as proxies for the undetected toluene in the ISM due to their much larger dipole moments. Competition between bimolecular and unimolecular products is extremely intense in the warmer and denser PANH-forming region of Titan's stratosphere. Computational results show that the fractions of tolunitriles, adducts, and benzonitrile are 19%-68%, 15%-64%, and 17%, respectively, at 150-200 K and 0.0001-0.001 atm (Titan's stratosphere). Then, benzonitrile and tolunitriles may contribute to the formation of PANHs by consecutive C2H additions. The kinetic information of aromatic nitriles for the CN + toluene reaction calculated here helps to explain the formation mechanism of polycyclic aromatic hydrocarbons or PANHs under different interstellar environments and constrains corresponding astrochemical models.

Keywords: Interstellar molecules, Titan, Reaction rates, Astrochemistry, Computational methods, Interstellar clouds, Interstellar medium
Molecular Gas and Star Formation in Nearby Starburst Galaxy Mergers. We employ the Feedback In Realistic Environments (FIRE-2) physics model to study how the properties of giant molecular clouds (GMCs) evolve during galaxy mergers. We conduct a pixel-by-pixel analysis of molecular gas properties in both the simulated control galaxies and galaxy major mergers. The simulated GMC pixels in the control galaxies follow a similar trend in a diagram of velocity dispersion (σ  v ) versus gas surface density (Σmol) to the one observed in local spiral galaxies in the Physics at High Angular resolution in Nearby GalaxieS (PHANGS) survey. For GMC pixels in simulated mergers, we see a significant increase of a factor of 5-10 in both Σmol and σ  v , which puts these pixels above the trend of PHANGS galaxies in the σ  v  versus Σmol diagram. This deviation may indicate that GMCs in the simulated mergers are much less gravitationally bound compared with simulated control galaxies with virial parameters (α vir) reaching 10-100. Furthermore, we find that the increase in α vir happens at the same time as the increase in global star formation rate, which suggests that stellar feedback is responsible for dispersing the gas. We also find that the gas depletion time is significantly lower for high-α vir GMCs during a starburst event. This is in contrast to the simple physical picture that low-α vir GMCs are easier to collapse and form stars on shorter depletion times. This might suggest that some other physical mechanisms besides self-gravity are helping the GMCs in starbursting mergers collapse and form stars.

Keywords: Starburst galaxies, Molecular gas, Giant molecular clouds, Star formation, Galaxy mergers
Digging into the Interior of Hot Cores with the ALMA (DIHCA). III. The Chemical Link between NH<SUB>2</SUB>CHO, HNCO, and H<SUB>2</SUB>CO. We have analyzed the NH2CHO, HNCO, H2CO, and CH3CN (13CH3CN) molecular lines at an angular resolution of ~0.″3 obtained by the Atacama Large Millimeter/submillimeter Array Band 6 toward 30 high-mass star-forming regions. The NH2CHO emission has been detected in 23 regions, while the other species have been detected toward 29 regions. A total of 44 hot molecular cores (HMCs) have been identified using the moment 0 maps of the CH3CN line. The fractional abundances of the four species have been derived at each HMC. In order to investigate pure chemical relationships, we have conducted a partial correlation test to exclude the effect of temperature. Strong positive correlations between NH2CHO and HNCO (ρ = 0.89) and between NH2CHO and H2CO (0.84) have been found. These strong correlations indicate their direct chemical links; dual-cyclic hydrogen addition and abstraction reactions between HNCO and NH2CHO and gas-phase formation of NH2CHO from H2CO. Chemical models including these reactions can reproduce the observed abundances in our target sources.

Keywords: Interstellar molecules, Massive stars, Star formation, Astrochemistry
COOL-LAMPS. IV. A Sample of Bright Strongly Lensed Galaxies at 3 &lt; z &lt; 4. We report the discovery of five bright, strong gravitationally lensed galaxies at 3 &lt; z &lt; 4: COOL J0101+2055 (z = 3.459), COOL J0104-0757 (z = 3.480), COOL J0145+1018 (z = 3.310), COOL J0516-2208 (z = 3.549), and COOL J1356+0339 (z = 3.753). These galaxies have magnitudes of r AB, z AB &lt; 21.81 mag and are lensed by galaxy clusters at 0.26 &lt; z &lt; 1. This sample nearly doubles the number of known bright lensed galaxies with extended arcs at 3 &lt; z &lt; 4. We characterize the lensed galaxies using ground-based grz/giy imaging and optical spectroscopy. We report model-based magnitudes and derive stellar masses, dust content, and star formation rates via stellar population synthesis modeling. Building lens models based on ground-based imaging, we estimate source magnifications ranging from ~29 to ~180. Combining these analyses, we derive demagnified stellar masses in the range ${\mathrm{log}}_{10}({M}_{* }/{M}_{\odot })\sim 9.69-10.75$ and star formation rates in the youngest age bin in the range ${\mathrm{log}}_{10}(\mathrm{SFR}/({M}_{\odot }\,{\mathrm{yr}}^{-1}))\sim 0.39-1.46$ , placing the sample galaxies on the massive end of the star-forming main sequence in this redshift interval. In addition, three of the five galaxies have strong Lyα emissions, offering unique opportunities to study Lyα emitters at high redshift in future work.

Keywords: Galaxy evolution, Strong gravitational lensing, High-redshift galaxies, Spectral energy distribution
The Effect of Superpositions on the Planetary Nebula Luminosity Function. Planetary nebula (PN) surveys in systems beyond ~10 Mpc often find high-excitation, point-like sources with [O III] λ5007 fluxes greater than the apparent bright-end cutoff of the planetary nebula luminosity function (PNLF). Here we identify PN superpositions as one likely cause for the phenomenon and describe the proper procedures for deriving PNLF distances when object blends are a possibility. We apply our technique to two objects: a model Virgo-distance elliptical galaxy observed through a narrowband interference filter, and the Fornax lenticular galaxy NGC 1380 surveyed with the MUSE integral-field unit spectrograph. Our analyses show that even when the most likely distance to a galaxy is unaffected by the possible presence of PN superpositions, the resultant value will still be biased toward too small a distance due to the asymmetrical nature of the error bars. We discuss the future of the PNLF in an era where current ground-based instrumentation can push the technique to distances beyond ~35 Mpc.

Keywords: Astrostatistics techniques, Galaxy distances, Planetary nebulae
Lack of Correlations between Cold Molecular Gas and AGN Properties in Type 1 AGNs at z ≲ 0.5. We present new NOrthern Extended Millimeter Array (NOEMA) observations of the CO(2-1) emission in eight of the brightest Palomar-Green quasars at z ≲ 0.5 to investigate the role of active galactic nucleus (AGN) feedback in luminous quasars detected at low redshifts. We detect CO(2-1) emission in three objects, from which we derive CO luminosities, molecular gas masses and fractions, and gas depletion times. In combination with data available in the literature, we build a total sample of 138 local type 1 AGNs with CO(2-1) measurements. We compare the AGN properties with the host galaxy molecular gas properties, considering systems nondetected in CO emission. We find that the CO luminosity does not correlate with AGN luminosity and Eddington ratio, while the molecular gas fraction is weakly correlated with Eddington ratio. The type 1 AGNs can be roughly separated into two populations in terms of infrared-to-CO luminosity ratio, with one population presenting values typically found in normal star-forming systems, while the other having lower ratio values, comparable to those measured for starbursts. We find no evidence that AGN feedback rapidly quenches star formation in type 1 AGNs. Our results may imply an underlying the role of host galaxy gravitational instabilities or the fast inflow of cold gas in triggering AGN activity.

Keywords: AGN host galaxies, Submillimeter astronomy, Quasars
ALMA Observation of a z ≳ 10 Galaxy Candidate Discovered with JWST. We report the observation by the Atacama Large Millimeter/submillimeter Array (ALMA) of a z ≳ 10 galaxy candidate (GHZ1) discovered from the GLASS-JWST Early Release Science Program. Our ALMA program aims to detect the [O III] emission line at the rest-frame frequency 3393.0062 GHz (88.36 μm) and far-IR continuum emission with the spectral window setup seamlessly covering a 26.125 GHz frequency range (10.10 &lt; z &lt; 11.14). A total of 7 hr of on-source integration was employed, using four frequency settings to cover the full range (1.7 hr per setting), with 0.″7 angular resolution. No line or continuum is clearly detected, with 5σ upper limits on the line emission of 0.93 mJy beam-1 at 25 km s-1 channel-1 and on the continuum emission of 30 μJy beam-1. We report marginal spectral (at 225 km s-1 resolution) and continuum features (4.1σ and 2.6σ peak signal-to-noise ratio, respectively), within 0.″17 from the JWST position of GHZ1. This spectral feature implies z = 10.38 and needs to be verified with further observations. Assuming that the best estimate of photometric redshift ( $z={10.60}_{-0.60}^{+0.52}$ ) is correct, the model of the galaxy's broadband spectral energy distribution for the 3σ upper limit of the continuum flux from GHZ1 suggests that GHZ1 has a small amount of dust (M  d  ≲ 104 M ⊙) at a high temperature (T  d  ≳ 90 K). The 5σ upper limit on the [O III]88μm line luminosity and the inferred star formation rate of GHZ1 are consistent with the properties of low-metallicity dwarf galaxies. We also report serendipitous clear detections of six continuum sources at the locations of the JWST galaxy counterparts in the field.

Keywords: Interstellar dust, Galaxy formation, Interferometers, Interstellar medium, Submillimeter astronomy, High-redshift galaxies
Interpretation of Flat Energy Spectra Upstream of Fast Interplanetary Shocks. Interplanetary shocks are large-scale heliospheric structures often caused by eruptive phenomena at the Sun, and represent one of the main sources of energetic particles. Several interplanetary (IP) shock crossings by spacecraft at 1 au have revealed enhanced energetic-ion fluxes that extend far upstream of the shock. Surprisingly, in some shock events ion fluxes with energies between 100 keV and about 2 MeV acquire similar values (which we refer to as "overlapped" fluxes), corresponding to flat energy spectra in that range. In contrast, closer to the shock the fluxes are observed to depend on energy. In this work, we analyze three IP-shock-related energetic particle events observed by the Advanced Composition Explorer spacecraft where flat ion energy spectra were observed upstream of the shock. We interpret these observations via a velocity-filter mechanism for particles in a given energy range. In particular, ions with velocity parallel to the local magnetic field larger than the speed of the upstream plasma, in the reference frame of the shock, can easily propagate back upstream, while lower-energy ions tend to be confined to the shock front, thus reducing their fluxes far upstream and giving rise to flat energy spectra. The velocity-filter mechanism has been corroborated from observations of particle flux anisotropy by the Solid-State Telescope of Wind/3DP.

Keywords: Interplanetary turbulence, Interplanetary shocks, Solar energetic particles