Sazuna/UAT_keywords huggingface dataset:
X-Ray Polarization of BL Lacertae in Outburst. We report the first &gt;99% confidence detection of X-ray polarization in BL Lacertae. During a recent X-ray/γ-ray outburst, a 287 ks observation (2022 November 27-30) was taken using the Imaging X-ray Polarimetry Explorer (IXPE), together with contemporaneous multiwavelength observations from the Neil Gehrels Swift observatory and XMM-Newton in soft X-rays (0.3-10 keV), NuSTAR in hard X-rays (3-70 keV), and optical polarization from the Calar Alto and Perkins Telescope observatories. Our contemporaneous X-ray data suggest that the IXPE energy band is at the crossover between the low- and high-frequency blazar emission humps. The source displays significant variability during the observation, and we measure polarization in three separate time bins. Contemporaneous X-ray spectra allow us to determine the relative contribution from each emission hump. We find &gt;99% confidence X-ray polarization ${{\rm{\Pi }}}_{2\mbox{--}4\mathrm{keV}}={21.7}_{-7.9}^{+5.6} \% $ and electric vector polarization angle ψ 2-4keV = -28.°7 ± 8.°7 in the time bin with highest estimated synchrotron flux contribution. We discuss possible implications of our observations, including previous IXPE BL Lacertae pointings, tentatively concluding that synchrotron self-Compton emission dominates over hadronic emission processes during the observed epochs.

Keywords: X-ray astronomy, Black hole physics, Supermassive black holes, Jets, Compact radiation sources, Active galaxies, Relativistic jets, Galaxy jets, Active galactic nuclei, Astrophysical black holes
A New Definition of Exoplanet Habitability: Introducing the Photosynthetic Habitable Zone. It may be possible to detect biosignatures of photosynthesis in an exoplanet's atmosphere. However, such a detection would likely require a dedicated study, occupying a large amount of telescope time. It is therefore prudent, while searching for signs of life that we may recognize, to pick the best target possible. In this work, we present a new region, the photosynthetic habitable zone (PHZ)-the distance from a star where both liquid water and oxygenic photosynthesis can occur. It is therefore the region where detectable biosignatures of oxygenic photosynthesis are most likely to occur. Our analysis indicates that in the most ideal conditions for life and no atmospheric effects, the PHZ is almost as broad as the habitable zone. On the other hand, if conditions for life are anything less than excellent and atmospheric effects are even moderate, the PHZ is concentrated at larger separations around more massive stars. Such cases are also not tidally locked to their host star, which could result in planetary rotation periods similar to the Earth's. We identify five planets, Kepler-452 b, Kepler-1638 b, Kepler-1544 b, Kepler-62 e, and Kepler-62 f, that are consistently in the PHZ for a variety of conditions, and we predict their day lengths to be between 9 and 11 hr. We conclude that the parameter space in which we should search for signs of life is much narrower than the standard habitable zone.

Keywords: Astrobiology, Exoplanets
Spectroscopic Characterization of Diazophosphane-A Candidate for Astrophysical Observations. Quite recently, diazophosphane, HP-N≡N, was synthesized for the first time. This was accomplished by a reaction of PH3 with N2 under UV irradiation at 193 nm. As these two molecules have been observed in different astrophysical environments, as for example, in the circumstellar medium and, in particular, in the AGB star envelope IRC+10216, the question arises whether HPN2 can be found as well. So far there is only the aforementioned experimental work, but neither rotational nor rovibrational data are available. Hence, the lack of accurate line lists, etc. to identify diazophosphane is the subject of this work, including a detailed analysis of the rotational, vibrational, and rovibrational properties for this molecule. Our calculations rely on multidimensional potential energy surfaces obtained from explicitly correlated coupled-cluster theory. The (ro)vibrational calculations are based on related configuration interaction theories avoiding the need for any model Hamiltonians. The rotational spectrum is studied between T = 10 and 300 K. In contrast, the partition functions for HPN2 and DPN2 are given and compared for temperatures up to 800 K. In addition, more than 70 vibrational transitions are calculated and analyzed with respect to resonances. All these vibrational states are considered within the subsequent rovibrational calculations. This allows for a detailed investigation of the infrared spectrum up to 2700 cm-1 including rovibrational couplings and hot bands. The results of this study serve as a reference and allow, for the first time, for the identification of diazophosphane, for example, in one of the astrophysical environments mentioned above.

Keywords: Molecular data, Infrared spectroscopy, Spectral line identification, Computational methods, Asymptotic giant branch stars, Molecular spectroscopic constants
Simulation of a Solar Jet Formed from an Untwisting Flux Rope Interacting with a Null Point. Coronal jets are eruptions identified by a collimated, sometimes twisted spire. They are small-scale energetic events compared with flares. Using multiwavelength observations from the Solar Dynamics Observatory/Atmospheric Imaging Assembly and a magnetogram from Hinode/Spectro-Polarimeter (Hinode/SP), we study the formation and evolution of a jet occurring on 2019 March 22 in NOAA Active Region 12736. A zero-β magnetohydrodynamic simulation is conducted to probe the initiation mechanisms and appearance of helical motion during this jet event. As the simulation reveals, there are two pairs of field lines at the jet base, indicating two distinct magnetic structures. One structure outlines a flux rope lying low above the photosphere in the north of a bald patch region, and the other structure shows a null point high in the corona in the south. The untwisting motions of the observed flux rope were recovered by adding an anomalous (artificial) resistivity in the simulation. A reconnection occurs at the bald patch in the flux rope structure, which is moving upward and simultaneously encounters the field lines of the null point structure. The interaction of the two structures results in the jet, while the twist of the flux rope is transferred to the jet by the reconnected field lines. The rotational motion of the flux rope is proposed to be an underlying trigger of this process and responsible for helical motions in the jet spire.

Keywords: Magnetohydrodynamics, Solar magnetic reconnection, Solar active regions, Solar magnetic fields, Solar activity
Constraints on the Epoch of Reionization with Roman Space Telescope and the Void Probability Function of Lyα Emitters. We use large simulations of Lyα emitters with different fractions of ionized intergalactic medium to quantify the clustering of Lyα emitters as measured by the void probability function (VPF), and how it evolves under different ionization scenarios. We quantify how well we might be able to distinguish between these scenarios with a deep spectroscopic survey using the future Nancy Grace Roman Space Telescope. Because Roman will be able to carry out blind spectroscopic surveys of Lyα emitters continuously between 7 &lt; z &lt; 12 to sensitivities of at least 10-17 erg s-1 over a wide field of view, it can measure the epoch of reionization as well as the pace of ionization of the intergalactic medium (IGM). We compare deep Roman surveys covering roughly 1, 4, and 16 deg2, and quantify what constraints on reionization the VPF may find for these surveys. A survey of 1 deg2 would distinguish between very late reionization and early reionization to 3σ near z = 7.7 with the VPF. The VPF of a 4 deg2 survey can distinguish between slow versus fast, as well as early versus late, reionization at &gt;3σ-4σ at several redshifts between 7 &lt; z &lt; 9. However, a survey of 13-16 deg2 would allow the VPF to give several robust constraints (&gt;5-8σ) across the epoch of reionization, and would yield a detailed history of the reionization of the IGM and its effect on Lyα emitter clustering.

Keywords: Lyman-alpha galaxies, Reionization, Clustering, Astronomical simulations
The Low-temperature Corona in ESO 511-G030 Revealed by NuSTAR and XMM-Newton. We present the results from a coordinated XMM-Newton + NuSTAR observation of the Seyfert 1 galaxy ESO 511-G030. With this joint monitoring program, we conduct a detailed variability and spectral analysis. The source remained in a low flux and very stable state throughout the observation period, although there are slight fluctuations of flux over long timescales. The broadband (0.3-78 keV) spectrum shows the presence of a power-law continuum with a soft excess below 2 keV, a relatively narrow iron Kα emission (~6.4 keV), and an obvious cutoff at high energies. We find that the soft excess can be modeled by two different possible scenarios: a warm (kT e ~ 0.19 keV) and optically thick (τ = 18-25) Comptonizing corona or a relativistic reflection from a high-density ( $\mathrm{log}[{n}_{{\rm{e}}}/{\mathrm{cm}}^{-3}]=17.1\mbox{--}18.5$ ) inner disk. All models require a low temperature (kT e ~ 13 keV) for the hot corona.

Keywords: Accretion, Seyfert galaxies, X-ray astronomy, Astrophysical black holes
Merger Signatures are Common, but not Universal, in Massive, Recently Quenched Galaxies at z   0.7. We present visual classifications of merger-induced tidal disturbances in 143 M * ~ 1011 M ⊙ post-starburst galaxies at z ~ 0.7 identified in the $\mathrm{SQuIGG}\vec{L}{\rm{E}}$ Sample. This sample spectroscopically selects galaxies from the Sloan Digital Sky Survey that have stopped their primary epoch of star formation within the past ~500 Myr. Visual classifications are performed on Hyper Suprime-Cam imaging. We compare to a control sample of mass- and redshift-matched star-forming and quiescent galaxies from the Large Early Galaxy Census and find that post-starburst galaxies are more likely to be classified as disturbed than either category. This corresponds to a factor of ${3.6}_{-1.3}^{+2.9}$ times the disturbance rate of older quiescent galaxies and ${2.1}_{-.73}^{+1.9}$ times the disturbance rate of star-forming galaxies. Assuming tidal features persist for ≲500 Myr, this suggests merging is coincident with quenching in a significant fraction of these post-starbursts. Galaxies with tidal disturbances are younger on average than undisturbed post-starburst galaxies in our sample, suggesting tidal features from a major merger may have faded over time. This may be exacerbated by the fact that, on average, the undisturbed subset is fainter, rendering low-surface-brightness tidal features harder to identify. However, the presence of 10 young (≲150 Myr since quenching) undisturbed galaxies suggests that major mergers are not the only fast physical mechanism that shut down the primary epoch of star formation in massive galaxies at intermediate redshift.

Keywords: Quenched galaxies, Post-starburst galaxies, Galaxy evolution, Galaxy mergers, Galaxy quenching, Galaxies
X-Ray Unveiling Events in a z ≈ 1.6 Active Galactic Nucleus in the 7 Ms Chandra Deep Field-South. We investigate the extreme X-ray variability of a z = 1.608 active galactic nucleus in the 7 Ms Chandra Deep Field-South (XID 403), which showed two significant X-ray brightening events. In the first event, XID 403 brightened by a factor of &gt;2.5 in ≲6.1 rest-frame days in the observed-frame 0.5-5 keV band. The event lasted for ≈5.0-7.3 days, and then XID 403 dimmed by a factor of &gt;6.0 in ≲6.1 days. After ≈1.1-2.5 yr in the rest frame (including long observational gaps), it brightened again, with the 0.5-5 keV flux increasing by a factor of &gt;12.6. The second event lasted over 251 days, and the source remained bright until the end of the 7 Ms exposure. The spectrum is a steep power law (photon index Γ = 2.8 ± 0.3) without obscuration during the second outburst, and the rest-frame 2-10 keV luminosity reaches ${1.5}_{-0.5}^{+0.8}\times {10}^{43}\,\mathrm{erg}\,{{\rm{s}}}^{-1}$ ; there is no significant spectral evolution within this epoch. The infrared-to-UV spectral energy distribution of XID 403 is dominated by the host galaxy. There is no significant optical/UV variability and R-band (rest-frame ≈2500 Å) brightening contemporaneous with the X-ray brightening. The extreme X-ray variability is likely due to two X-ray unveiling events, where the line of sight to the corona is no longer shielded by high-density gas clumps in a small-scale dust-free absorber. XID 403 is probably a high-redshift analog of local narrow-line Seyfert 1 galaxies, and the X-ray absorber is a powerful accretion disk wind. On the other hand, we cannot exclude the possibility that XID 403 is an unusual candidate for tidal disruption events.

Keywords: Surveys, Active galactic nuclei, Seyfert galaxies, X-ray active galactic nuclei
Effects of Emerging Bipolar Magnetic Regions in Mean-field Dynamo Model of Solar Cycles 23 and 24. We model the physical parameters of Solar Cycles 23 and 24 using a nonlinear dynamical mean-field dynamo model that includes the formation and evolution of bipolar magnetic regions (BMRs). The Parker-type dynamo model consists of a complete MHD system in the mean-field formulation: the 3D magnetic induction equation, and 2D momentum and energy equations in the anelastic approximation. The initialization of BMRs is modeled in the framework of Parker's magnetic buoyancy instability. It defines the depths of BMR injections, which are typically located at the edge of the global dynamo waves. The distribution with longitude and latitude and the size of the initial BMR perturbations are taken from the NOAA database of active regions. The modeling results are compared with various observed characteristics of the solar cycles. Only the BMR perturbations located in the upper half of the convection zone lead to magnetic active regions on the solar surface. While the BMRs initialized in the lower part of the convection zone do not emerge on the surface, they still affect the global dynamo process. Our results show that BMRs can play a substantial role in the dynamo processes and affect the strength of the solar cycles. However, the data driven model shows that the BMR's effect alone cannot explain the weak Cycle 24. This weak cycle and the prolonged preceding minimum of magnetic activity were probably caused by a decrease of the turbulent helicity in the bulk of the convection zone during the decaying phase of Cycle 23.

Keywords: The Sun, Solar magnetic fields, Solar physics
Magnetic Tornado Properties: A Substantial Contribution to the Solar Coronal Heating via Efficient Energy Transfer. In solving the solar coronal heating problem, it is crucial to comprehend the mechanisms by which energy is conveyed from the photosphere to the corona. Recently, magnetic tornadoes, characterized as coherent, rotating magnetic-field structures extending from the photosphere to the corona, have drawn growing interest as a possible means of efficient energy transfer. Despite its acknowledged importance, the underlying physics of magnetic tornadoes remains elusive. In this study, we conduct a three-dimensional radiative magnetohydrodynamic simulation that encompasses the upper convective layer and extends into the corona, with a view to investigating how magnetic tornadoes are generated and efficiently transfer energy into the corona. We find that a single event of magnetic flux concentration merger on the photosphere gives rise to the formation of a single magnetic tornado. The Poynting flux transferred into the corona is found to be four times greater in the presence of the magnetic tornado, as compared to its absence. This increase is attributed to a reduction in energy loss in the chromosphere, resulting from the weakened magnetic-energy cascade. Based on an evaluation of the fraction of the merging events, our results suggest that magnetic tornadoes contribute approximately 50% of the Poynting flux into the corona in regions where the coronal magnetic-field strength is 10 G. Potentially, the contribution could be even greater in areas with a stronger coronal magnetic field.

Keywords: Radiative magnetohydrodynamics, Solar photosphere, Solar magnetic fields, Solar corona, Solar chromosphere
Kinematics, Structure, and Mass Outflow Rates of Extreme Starburst Galactic Outflows. We present results on the properties of extreme gas outflows in massive (M * ~ 1011 M ⊙), compact, starburst (star formation rate, SFR~ 200 M ⊙ yr-1) galaxies at z = 0.4-0.7 with very high star formation surface densities (ΣSFR ~ 2000 M ⊙ yr-1 kpc-2). Using optical Keck/HIRES spectroscopy of 14 HizEA starburst galaxies, we identify outflows with maximum velocities of 820-2860 km s-1. High-resolution spectroscopy allows us to measure precise column densities and covering fractions as a function of outflow velocity and characterize the kinematics and structure of the cool gas outflow phase (T ~ 104 K). We find substantial variation in the absorption profiles, which likely reflects the complex morphology of inhomogeneously distributed, clumpy gas and the intricacy of the turbulent mixing layers between the cold and hot outflow phases. There is not a straightforward correlation between the bursts in the galaxies' star formation histories and their wind absorption line profiles, as might naively be expected for starburst-driven winds. The lack of strong Mg II absorption at the systemic velocity is likely an orientation effect, where the observations are down the axis of a blowout. We infer high mass outflow rates of ~50-2200 M ⊙ yr-1, assuming a fiducial outflow size of 5 kpc, and mass loading factors of η ~ 5 for most of the sample. While these values have high uncertainties, they suggest that starburst galaxies are capable of ejecting very large amounts of cool gas that will substantially impact their future evolution.

Keywords: Galaxy evolution, Starburst galaxies, Stellar feedback
The Parallax and 3D Kinematics of Water Masers in the Massive Star-forming Region G034.43+0.24. We report a measurement of the trigonometric parallax of 22 GHz water masers in the massive star-forming region G034.43+0.24 as part of the Bar and Spiral Structure Legacy Survey using the Very Long Baseline Array. The parallax is 0.330 ± 0.018 mas, corresponding to a distance of ${3.03}_{-0.16}^{+0.17}$ kpc. This locates G034.43+0.24 near the inner edge of the Sagittarius spiral arm and at one end of a linear distribution of massive young stars that cross nearly the full width of the arm. The measured three-dimensional motion of G034.43+0.24 indicates a near-circular Galactic orbit. The water masers display arc-like distributions, possibly bow shocks, associated with winds from one or more massive young stars.

Keywords: Trigonometric parallax, Star formation, Milky Way Galaxy, Interstellar masers
Bayesian Analysis of Neutron-star Properties with Parameterized Equations of State: The Role of the Likelihood Functions. We have investigated the systematic differences introduced when performing a Bayesian-inference analysis of the equation of state (EOS) of neutron stars employing either variable- or constant-likelihood functions. The former has the advantage of retaining the full information on the distributions of the measurements, making exhaustive usage of the data. The latter, on the other hand, has the advantage of a much simpler implementation and reduced computational costs. In both approaches, the EOSs have identical priors and have been built using the sound speed parameterization method so as to satisfy the constraints from X-ray and gravitational waves observations, as well as those from chiral effective theory and perturbative quantum chromodynamics. In all cases, the two approaches lead to very similar results and the 90% confidence levels essentially overlap. Some differences do appear, but in regions where the probability density is extremely small and are mostly due to the sharp cutoff on the binary tidal deformability $\tilde{{\rm{\Lambda }}}\leqslant 720$ set in the constant-likelihood approach. Our analysis has also produced two additional results. First, an inverse correlation between the normalized central number density, n  c,TOV/n  s , and the radius of a maximally massive star, R TOV. Second, and most importantly, it has confirmed the relation between the chirp mass and the binary tidal deformability. The importance of this result is that it relates ${{ \mathcal M }}_{\mathrm{chirp}}$ , which is measured very accurately, and $\tilde{{\rm{\Lambda }}}$ , which contains important information on the EOS. Hence, when ${{ \mathcal M }}_{\mathrm{chirp}}$ is measured in future detections, our relation can be used to set tight constraints on $\tilde{{\rm{\Lambda }}}$ .

Keywords: Bayesian statistics, Neutron star cores, Nuclear physics
Machine Learning Applied to X-Ray Spectra: Separating Stars in Orion Nebula Cluster from Active Galactic Nuclei in CDFS. Modern X-ray telescopes have detected hundreds of thousands of X-ray sources in the universe. However, current methods to classify these sources using the X-ray data themselves suffer problems-detailed X-ray spectroscopy of individual sources is too time consuming, while hardness ratios often lack accuracy, and can be difficult to use effectively. These methods fail to use the power of X-ray CCD detectors to identify X-ray emission lines and distinguish line-dominated spectra (from chromospherically active stars, supernova remnants, etc.) from continuum-dominated ones (e.g., compact objects or active galactic nuclei, AGN). In this paper, we probe the use of artificial neural networks (ANN) in differentiating Chandra spectra of young stars in the Chandra Orion Ultradeep Project (COUP) survey from AGN in the Chandra Deep Field South (CDFS) survey. We use these surveys to generate 100,000 artificial spectra of stars and AGN, and train our ANN models to separate the two kinds of spectra. We find that our methods reach an accuracy of ~92% in classifying simulated spectra of moderate-brightness objects in typical exposures, but their performance decreases on the observed COUP and CDFS spectra (~91%), due in large part to the relatively high background of these long-exposure data sets. We also investigate the performance of our methods with changing properties of the spectra such as the net source counts, the relative contribution of background, the absorption column of the sources, etc. We conclude that these methods have substantial promise for application to large X-ray surveys.

Keywords: Neural networks, X-ray identification, X-ray active galactic nuclei, X-ray surveys, X-ray stars
The Mass of the Black Hole in NGC 5273 from Stellar Dynamical Modeling. We present a new constraint on the mass of the black hole in the active S0 galaxy NGC 5273. Due to the proximity of the galaxy at 16.6 ± 2.1 Mpc, we were able to resolve and extract the bulk motions of stars near the central black hole using adaptive-optics-assisted observations with the Gemini Near-infrared Integral Field Spectrograph, as well as constrain the large-scale kinematics using archival Spectroscopic Areal Unit for Research and Optical Nebulae spectroscopy. High-resolution Hubble Space Telescope imaging allowed us to generate a surface-brightness decomposition, determine approximate mass-to-light ratios for the bulge and disk, and obtain an estimate for the disk inclination. We constructed an extensive library of dynamical models using the Schwarzschild orbit-superposition code FORSTAND, exploring a range of disk and bulge shapes, halo masses, etc. We determined a black hole mass of M ∙ = [0.5-2] × 107 M ☉, where the low side of the range is in agreement with the reverberation mapping measurement of M ∙ = [4.7 ± 1.6] × 106 M ☉. NGC 5273 is one of the few nearby galaxies that hosts a broad-lined active galactic nucleus, allowing a crucial comparison of black hole masses derived from independent mass-measurement techniques.

Keywords: AGN host galaxies, Supermassive black holes, Seyfert galaxies, Stellar dynamics