adsabs/SciX_UAT_keywords huggingface dataset:
Extended MCDHF Calculations of Energy Levels and Transition Data for N I

Accurate and extensive atomic data are essential for spectroscopic analyses of stellar atmospheres and other astronomical objects. We present energy levels, lifetimes, and transition probabilities for neutral nitrogen, the sixth most abundant element in the cosmos. The calculations employ the fully relativistic multiconfiguration Dirac-Hartree-Fock and relativistic configuration interaction methods, and span the 103 lowest states up to and including 2s22p25s. Our theoretical energies are in excellent agreement with the experimental data, with an average relative difference of 0.07%. In addition, our transition probabilities are in good agreement with available experimental and theoretical data. We further verify the agreement of our data with experimental results via a reanalysis of the solar nitrogen abundance, with the results from the Babushkin and Coulomb gauges consistent to 2% or 0.01 dex. We estimated the uncertainties of the computed transition data based on a statistical analysis of the differences between the transition rates in the Babushkin and Coulomb gauges. Out of the 1701 computed electric dipole transitions in this work, 83 (536) are associated with uncertainties smaller than 5% (10%).

Keywords: atomic data; solar abundances
C/2014 UN271 (Bernardinelli-Bernstein): The Nearly Spherical Cow of Comets

Comet C/2014 UN271 (Bernardinelli-Bernstein), incoming from the Oort cloud, is remarkable in having the brightest (and presumably largest) nucleus of any well-measured comet and having been discovered at the heliocentric distance rh ≈ 29 au, farther than any Oort cloud comet. In this work, we describe the discovery process and observations and the properties that can be inferred from images recorded until the first reports of activity in 2021 June. The orbit has i = 95°, with a perihelion of 10.97 au to be reached in 2031 and a previous aphelion at 40,400 ± 260 au. Backward integration of the orbit under a standard Galactic tidal model and known stellar encounters suggests a perihelion of q ≈ 18 au on its previous perihelion passage 3.5 Myr ago; hence, the current data could be the first ever obtained of a comet that has not been inside Uranus's orbit in 4 Gyr. The photometric data show an unresolved nucleus with absolute magnitude Hr = 8.0, colors that are typical of comet nuclei or Damocloids, and no secular trend as it traversed the range 34-23 au. For the r-band geometric albedo pr, this implies a diameter of $150{({p}_{r}/0.04)}^{-0.5}$ km. There is strong evidence of brightness fluctuations at the ±0.2 mag level, but no rotation period can be discerned. A coma, nominally consistent with a "stationary" 1/ρ surface brightness distribution, grew in scattering cross section at an exponential rate from Afρ ≈ 1 to ≈150 m as the comet approached from 28 to 20 au. The activity rate is consistent with a very simple model of sublimation of a surface species in radiative equilibrium with the Sun. The inferred enthalpy of sublimation matches those of CO2 and NH3. More volatile species, such as N2, CH4, and CO, must be far less abundant on the sublimating surfaces.

Keywords: long period comets; small solar system bodies; comet nuclei; comet dynamics; comet origins
Structure, Kinematics, and Observability of the Large Magellanic Cloud's Dynamical Friction Wake in Cold versus Fuzzy Dark Matter

The Large Magellanic Cloud (LMC) will induce a dynamical friction (DF) wake on infall to the Milky Way (MW). The MW's stellar halo will respond to the gravity of the LMC and the dark matter (DM) wake, forming a stellar counterpart to the DM wake. This provides a novel opportunity to constrain the properties of the DM particle. We present a suite of high-resolution, windtunnel-style simulations of the LMC's DF wake that compare the structure, kinematics, and stellar tracer response of the DM wake in cold DM (CDM), with and without self-gravity, versus fuzzy DM (FDM) with m a = 10-23 eV. We conclude that the self-gravity of the DM wake cannot be ignored. Its inclusion raises the wake's density by ~10%, and holds the wake together over larger distances (~50 kpc) than if self-gravity is ignored. The DM wake's mass is comparable to the LMC's infall mass, meaning the DM wake is a significant perturber to the dynamics of MW halo tracers. An FDM wake is more granular in structure and is ~20% dynamically colder than a CDM wake, but with comparable density. The granularity of an FDM wake increases the stars' kinematic response at the percent level compared to CDM, providing a possible avenue of distinguishing a CDM versus FDM wake. This underscores the need for kinematic measurements of stars in the stellar halo at distances of 70-100 kpc.

Keywords: large magellanic cloud; milky way dynamics; milky way dark matter halo; milky way stellar halo; dynamical friction; cold dark matter
Gaia EDR3 Parallax Zero-point Offset Based on W Ursae Majoris-type Eclipsing Binaries

We independently determine the zero-point offset of the Gaia early Data Release-3 (EDR3) parallaxes based on ∼110,000 W Ursae Majoris (EW)-type eclipsing binary systems. EWs cover almost the entire sky and are characterized by a relatively complete coverage in magnitude and color. They are an excellent proxy for Galactic main-sequence stars. We derive a W1-band period-luminosity relation with a distance accuracy of 7.4%, which we use to anchor the Gaia parallax zero-point. The final, global parallax offsets are -28.6 ± 0.6 μas and -25.4 ± 4.0 μas (before correction) and 4.2 ± 0.5 μas and 4.6 ± 3.7 μas (after correction) for the five- and six-parameter solutions, respectively. The total systematic uncertainty is 1.8 μas. The spatial distribution of the parallax offsets shows that the bias in the corrected Gaia EDR3 parallaxes is less than 10 μas across 40% of the sky. Only 15% of the sky is characterized by a parallax offset greater than 30 μas. Thus, we have provided independent evidence that the parallax zero-point correction provided by the Gaia team significantly reduces the prevailing bias. Combined with literature data, we find that the overall Gaia EDR3 parallax offsets for Galactic stars are [-20, -30] μas and 4-10 μas, respectively, before and after correction. For specific regions, an additional deviation of about 10 μas is found.

Keywords: parallax; eclipsing binary stars; w ursae majoris variable stars; catalogs; close binary stars
Periodic Fast Radio Bursts as a Probe of Extragalactic Asteroid Belts

The periodic activity of the repeating fast radio burst (FRB) 180916.J0158+65 was recently reported by the CHIME/FRB Collaboration team. From this source 28 bursts not only show a ∼16 day period with an active phase of ∼4.0 days, but they also exhibit a broken power law in differential energy distribution. In this Letter, we suggest that FRB 180916.J0158+65-like periodic FRBs could provide a unique probe of extragalactic asteroid belts (EABs), based on our previously proposed pulsar-EAB impact model, in which repeating FRBs arise from an old-aged, slowly spinning, moderately magnetized pulsar traveling through an EAB around another stellar-mass object. These two objects form a binary, and thus the observed period is in fact the orbital period. We show that this model can be used to well interpret all of the observed data of FRB 180916.J0158+65. Furthermore, we constrain the EAB's physical properties and find that (1) the outer radius of the EAB is at least an order of magnitude smaller than that of its analog in the solar system, (2) the differential size distribution of the EAB's asteroids at small diameters (large diameters) is shallower (steeper) than that of solar system small objects, and (3) the two belts have a comparable mass.

Keywords: radio bursts; asteroids; minor planets; radio continuum emission; neutron stars
The MKID Exoplanet Camera for Subaru SCExAO

We present the MKID Exoplanet Camera (MEC), a z through J band (800-1400 nm) integral field spectrograph located behind The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) at the Subaru Telescope on Maunakea that utilizes Microwave Kinetic Inductance Detectors (MKIDs) as the enabling technology for high contrast imaging. MEC is the first permanently deployed near-infrared MKID instrument and is designed to operate both as an IFU, and as a focal plane wavefront sensor in a multi-kHz feedback loop with SCExAO. The read noise free, fast time domain information attainable by MKIDs allows for the direct probing of fast speckle fluctuations that currently limit the performance of most high contrast imaging systems on the ground and will help MEC achieve its ultimate goal of reaching contrasts of 10-7 at 2 λ/D. Here we outline the instrument details of MEC including the hardware, firmware, and data reduction and analysis pipeline. We then discuss MEC's current on-sky performance and end with future upgrades and plans.

Keywords: direct imaging; astronomical instrumentation; astronomical detectors
HAWC Detection of a TeV Halo Candidate Surrounding a Radio-quiet Pulsar

Extended very-high-energy (VHE; 0.1-100 TeV) γ-ray emission has been observed around several middle-aged pulsars and referred to as "TeV halos." Their formation mechanism remains under debate. It is also unknown whether they are ubiquitous or related to a certain subgroup of pulsars. With 2321 days of observation, the High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory detected VHE γ-ray emission at the location of the radio-quiet pulsar PSR J0359+5414 with >6σ significance. By performing likelihood tests with different spectral and spatial models and comparing the TeV spectrum with multiwavelength observations of nearby sources, we show that this excess is consistent with a TeV halo associated with PSR J0359+5414, though future observation of HAWC and multiwavelength follow-ups are needed to confirm this nature. This new halo candidate is located in a noncrowded region in the outer galaxy. It shares similar properties to the other halos but its pulsar is younger and radio-quiet. Our observation implies that TeV halos could commonly exist around pulsars and their formation does not depend on the configuration of the pulsar magnetosphere.

Keywords: pulsars; gamma-ray astronomy; high energy astrophysics
The XMM-Newton Line Emission Analysis Program (X-LEAP). II. The Multiscale Temperature Structures in the Milky Way Hot Gas

This paper presents the multiscale temperature structures in the Milky Way (MW) hot gas, as part of the XMM-Newton Line Emission Analysis Program, surveying the O VII, O VIII, and Fe-L band emission features in the XMM-Newton archive. In particular, we define two temperature tracers, I OVIII/I OVII (O87) and I FeL/(I OVII + I OVIII) (FeO). These two ratios cannot be explained simultaneously using single-temperature collisional ionization models, which indicates the need for multitemperature structures in hot gas. In addition, we show three large-scale features in the hot gas: the eROSITA bubbles around the Galactic center (GC), the disk, and the halo. In the eROSITA bubbles, the observed line ratios can be explained by a log-normal temperature distribution with a median of $\mathrm{log}T/{\rm{K}}\approx 6.4$ and a scatter of σ T ≈ 0.2 dex. Beyond the bubbles, the line ratio dependence on the Galactic latitude suggests higher temperatures around the midplane of the MW disk. The scale height of the temperature variation is estimated to be ≈2 kpc assuming an average distance of 5 kpc for the hot gas. The halo component is characterized by the dependence on the distance to the GC, showing a temperature decline from $\mathrm{log}\,T/{\rm{K}}\,\approx 6.3$ to 5.8. Furthermore, we extract the autocorrelation and cross-correlation functions to investigate the small-scale structures. O87 and FeO ratios show a consistent autocorrelation scale of ≈5° (i.e., ≈400 pc at 5 kpc), which is consistent with the expected physical sizes of X-ray bubbles associated with star-forming regions or supernova remnants. Finally, we examine the cross-correlation between the hot and UV-detected warm gas and show an intriguing anticorrelation.

Keywords: diffuse x-ray background; circumgalactic medium; hot ionized medium
On the Reliability of Photometric and Spectroscopic Tracers of Halo Relaxation

We characterize the relaxation state of galaxy systems by providing an assessment of the reliability of the photometric and spectroscopic probe via the semianalytic galaxy evolution model. We quantify the correlations between the dynamical age of simuglated galaxy groups and popular proxies of halo relaxation in observation, which are mainly either spectroscopic or photometric. We find the photometric indicators demonstrate a stronger correlation with the dynamical relaxation of galaxy groups compared to the spectroscopic probes. We take advantage of the Anderson Darling statistic (A2) and the velocity segregation ( $\overline{{\rm{\Delta }}V}$ ) as our spectroscopic indicators, and use the luminosity gap (Δm12) and the luminosity decentering (Doffset) as photometric ones. First, we find that a combination of Δm12 and Doffset evaluated by a bivariant relation ( ${\rm{B}}=0.04\times {\rm{\Delta }}{m}_{12}-0.11\times \mathrm{Log}({D}_{\mathrm{off}-\mathrm{set}})+0.28$ ) shows a good correlation with the dynamical age compared to all other indicators. Second, by using the observational X-ray surface brightness map, we show that the bivariant relation brings about some acceptable correlations with X-ray proxies. These correlations are as well as the correlations between A2 and X-ray proxies, offering a reliable yet fast and economical method of quantifying the relaxation of galaxy systems. This study demonstrates that using photometric data to determine the relaxation status of a group will lead to some promising results that are comparable with the more expensive spectroscopic counterpart.

Keywords: galaxy clusters; galactic and extragalactic astronomy; galaxy groups; sloan photometry; n-body simulations
CEERS MIRI Imaging: Data Reduction and Quality Assessment

The Cosmic Evolution Early Release Science Survey (CEERS), targeting the Extended Groth Strip extragalactic field, is one of the James Webb Space Telescope Director's Discretionary Early Release Science programs. To date, all observations have been executed and include NIRCam/MIRI imaging and NIRSpec/NIRCam spectroscopic exposures. Here we discuss the MIRI imaging, which includes eight pointings, four of which provide deep imaging with the bluer bands (F560W and F770W) and four of which provide contiguous wavelength coverage in F1000W, F1280W, F1500W, and F1800W, where two of these also include coverage in F770W and F2100W. We present a summary of the data, data quality, and data reduction. The data reduction is based on the JWST CALIBRATION PIPELINE combined with custom modifications and additional steps designed to enhance the output quality, including improvements in astrometry and the removal of detector artifacts. We estimate the image depth of the reduced mosaics and show that these generally agree with expectations from the Exposure Time Calculator. We compare the MIRI F560W and F770W flux densities for bright sources to measurements from Spitzer/IRAC Ch3 (5.8 μm) and Ch4 (8.0 μm), and we find that they agree with systematic differences of <0.1 mag. For the redder MIRI bands, we assess their quality by studying the spectral energy distributions (SEDs) of Galactic stars. The SEDs are consistent with the expected Rayleigh-Jeans law with a deviation of ~0.03 mag, indicating that the MIRI colors are reliable. We also discuss all publicly released data products (images and source catalogs), which are available on the CEERS website (https://ceers.github.io/).

Keywords: james webb space telescope; galaxy evolution; star formation; astronomy data reduction; active galactic nuclei; infrared photometry; infrared sources
Helium-deficient ER UMa-type Dwarf Nova below the Period Minimum with a Hot Secondary

We present the discovery of a peculiar dwarf nova KSP-OT-201712a using high-cadence, multicolor observations made with the Korea Microlensing Telescope Network. KSP-OT-201712a exhibits a rare presence of outbursts during standstills, as well as strong Hα emission for a dwarf nova below the period minimum with an orbital period of 58.75 ± 0.02 minutes. The outburst cycles are ∼6.6 days within standstills but increase to ∼15 days outside of them. Both B ‑ V and V ‑ I colors become bluer and redder as the outburst luminosities increase and decrease, respectively, for the outburst within standstill, while they evolve in the opposite directions outside of the standstills. The presence of strong double-peaked Hα and weak He I emission lines with He/H flux ratio of 0.27, together with absorption lines of Mg b and Na D in the source, leads to the estimation T eff ≃ 4570 ± 40 K, [Fe/H] ≃ 0.06 ± 0.15 dex, and log g ≃ 4.5 ± 0.1 for its secondary. KSP-OT-201712a is the second He-deficient dwarf nova below the period minimum, while the temperature of the secondary is measured for the first time in such objects. We identify it to be an ER UMa-type dwarf nova, suggesting that the evolution of dwarf novae across the period minimum is accompanied by large mass transfers. The high temperature of the secondary indicates that the system started its mass transfer when the secondary was about 93% of its main-sequence age. The system will evolve to a helium cataclysmic variable or to AM CVn once its hydrogen envelope is exhausted before it explodes as a Type Ia supernova.

Keywords: dwarf novae; novae
The Sloan Digital Sky Survey Reverberation Mapping Project: The Black Hole Mass-Stellar Mass Relations at 0.2 ≲ z ≲ 0.8

We measure the correlation between black hole mass M BH and host stellar mass M * for a sample of 38 broad-line quasars at 0.2 ≲ z ≲ 0.8 (median redshift z med = 0.5). The black hole masses are derived from a dedicated reverberation mapping program for distant quasars, and the stellar masses are derived from two-band optical+IR Hubble Space Telescope imaging. Most of these quasars are well centered within ≲1 kpc from the host galaxy centroid, with only a few cases in merging/disturbed systems showing larger spatial offsets. Our sample spans two orders of magnitude in stellar mass (~109-1011 M ⊙) and black hole mass (~107-109 M ⊙) and reveals a significant correlation between the two quantities. We find a best-fit intrinsic (i.e., selection effects corrected) M BH-M *,host relation of $\mathrm{log}({M}_{\mathrm{BH}}/{M}_{\odot })={7.01}_{-0.33}^{+0.23}+{1.74}_{-0.64}^{+0.64}\mathrm{log}({M}_{* ,\mathrm{host}}/{10}^{10}{M}_{\odot })$ , with an intrinsic scatter of ${0.47}_{-0.17}^{+0.24}$ dex. Decomposing our quasar hosts into bulges and disks, there is a similar M BH-M *,bulge relation with slightly larger scatter, likely caused by systematic uncertainties in the bulge-disk decomposition. The M BH-M *,host relation at z med = 0.5 is similar to that in local quiescent galaxies, with negligible evolution over the redshift range probed by our sample. With direct black hole masses from reverberation mapping and the large dynamical range of the sample, selection biases do not appear to affect our conclusions significantly. Our results, along with other samples in the literature, suggest that the locally measured black hole mass-host stellar mass relation is already in place at z ~ 1.

Keywords: active galaxies; agn host galaxies; quasars; surveys; black hole physics
Two Sequences in the Age-Metallicity Relation as Seen from [C/N] Abundances in APOGEE

The age-metallicity relation (AMR) is fundamental to study the formation and evolution of the disk. Observations have shown that this relation has a large scatter, which cannot be explained by observational errors only. That scatter is hence attributed to the effects of radial migration in which stars tracing different chemical evolution histories in the disk get mixed. However, the recent study of Nissen et al., using high-precision observational data of solar-type stars, found two relatively tight AMRs. One sequence of older and metal-richer stars probably traces the chemical enrichment history of the inner disk while the other sequence of younger and metal-poorer stars traces the chemical enrichment history of the outer disk. If uncertainties in age measurements increase, these sequences mix, explaining the scatter of the one relation observed in other studies. This work follows up on these results by analyzing an independent sample of red clump giants observed by APOGEE. Because ages for red giants are significantly more uncertain, the [C/N] ratios are considered as a proxy for age. This larger data set is used to investigate these relations at different Galactic radii, finding that these distinct sequences exist only in the solar neighborhood. The APOGEE data set is further used to explore different abundance and kinematical planes to shed light on the nature of these populations.

Keywords: chemical abundances; milky way disk
Effects of Cowling Resistivity in the Weakly Ionized Chromosphere

The physics of the solar chromosphere is complex from both theoretical and modeling perspectives. The plasma temperature from the photosphere to the corona increases from ∼5000 K to ∼1 million K over a distance of only ∼10,000 km from the chromosphere and the transition region. Certain regions of the solar atmosphere have sufficiently low temperature and ionization rates to be considered as weakly ionized. In particular, this is true at the lower chromosphere. As a result, the Cowling resistivity is orders of magnitude greater than the Coulomb resistivity. Ohm's law therefore includes anisotropic dissipation. To evaluate the Cowling resistivity, we need to know the external magnetic field strength and to estimate the neutral fraction as a function of the bulk plasma density and temperature. In this study, we determine the magnetic field topology using the non-force-free field extrapolation technique based on Solar Dynamics Observatory/Helioseismic and Magnetic Imager SHARP vector magnetogram data, and the stratified density and temperature profiles from the Maltby-M umbral core model for sunspots. We investigate the variation and effects of Cowling resistivity on heating and magnetic reconnection in the chromosphere as the flare-producing active region (AR) 11166 evolves. In particular, we analyze a C2.0 flare emerging from AR 11166 and find a normalized reconnection rate of 0.051.

Keywords: magnetohydrodynamics; solar chromosphere; solar active regions; solar active region magnetic fields; solar chromospheric heating; solar magnetic reconnection