adsabs/SciX_UAT_keywords huggingface dataset:
A Light Redback Companion of PSR J1622-0315 and Irradiation Power in Spider Systems

We report optical observations of the millisecond pulsar binary system PSR J1622-0315 with the Lulin 1 m telescope in Taiwan and the Lijiang 2.4 m telescope in China between 2019 and 2021. The companion of the pulsar, which is of V ~ 19 mag, showed ellipsoidal-distorted orbital variations in its light curves. The best-fit model to the light curves, with the binary code PHOEBE, gives a companion mass of 0.122 ± 0.006 M ⊙. This places PSR J1622-0315 in the spider-system subclass. We compared the properties of PSR J1622-0315 with other spider pulsar binaries for the scalings between the spin-down luminosity derived for the pulsar, irradiation luminosity of the companion, and X-ray luminosity of the binary. We find that pulsar irradiation in PSR J1622-0315 is insignificant and the irradiation luminosity of the transitional millisecond pulsars PSR J1023+0038 and PSR J1227-4853 are the highest among the redback systems.

Keywords: millisecond pulsars; compact binary stars; low-mass x-ray binary stars
21 cm Intensity Mapping with the DSA-2000

Line-intensity mapping is a promising probe of the Universe's large-scale structure. We explore the sensitivity of the DSA-2000, a forthcoming array consisting of over 2000 dishes, to the statistical power spectrum of neutral hydrogen's 21 cm emission line. These measurements would reveal the distribution of neutral hydrogen throughout the near-redshift Universe without necessitating resolving individual sources. The success of these measurements relies on the instrument's sensitivity and resilience to systematics. We show that the DSA-2000 will have the sensitivity needed to detect the 21 cm power spectrum at z ≈ 0.5 and across power spectrum modes of 0.03–35.12 h Mpc‑1 with 0.1 h Mpc‑1 resolution. We find that supplementing the nominal array design with a dense core of 200 antennas will expand its sensitivity at low power spectrum modes and enable measurement of Baryon Acoustic Oscillations. Finally, we present a qualitative discussion of the DSA-2000's unique resilience to sources of systematic error that can preclude 21 cm intensity mapping.

Keywords: cosmology; h i line emission; interferometry; radio interferometry
The CatWISE Preliminary Catalog: Motions from WISE and NEOWISE Data

CatWISE is a program to catalog sources selected from combined WISE and NEOWISE all-sky survey data at 3.4 and 4.6 &mgrm (W1 and W2). The CatWISE Preliminary Catalog consists of 900,849,014 sources measured in data collected from 2010 to 2016. This data set represents four times as many exposures and spans over 10 times as large a time baseline as that used for the AllWISE Catalog. CatWISE adapts AllWISE software to measure the sources in coadded images created from six-month subsets of these data, each representing one coverage of the inertial sky, or epoch. The catalog includes the measured motion of sources in eight epochs over the 6.5 yr span of the data. From comparison to Spitzer, signal-to-noise ratio = 5 limits in magnitudes in the Vega system are W1 &equals 17.67 and W2 = 16.47, compared to W1 &equals 16.96 and W2 = 16.02 for AllWISE. From comparison to Gaia, CatWISE positions have typical accuracies of 50 mas for stars at W1 &equals 10 mag and 275 mas for stars at W1 = 15.5 mag. Proper motions have typical accuracies of 10 mas yr-1 and 30 mas yr-1 for stars with these brightnesses, an order of magnitude better than from AllWISE. The catalog is available in the WISE/NEOWISE Enhanced and Contributed Products area of the NASA/IPAC Infrared Science Archive.

Keywords: catalogs; sky surveys; proper motions; brown dwarfs; infrared astronomy
S0-2 Star, G1- and G2-objects, and Flaring Activity of the Milky Way's Galactic Center Black Hole in 2019

In 2019, the Galactic center black hole Sgr A* produced an unusually high number of bright near-infrared flares, including the brightest-ever detected flare. We propose that this activity was triggered by the near simultaneous infall of material shed by G1 and G2 objects due to their interaction with the background accretion flow. We discuss mechanisms by which S-stars and G-objects shed material, and estimate both the quantity of material and the infall time to reach the black hole.

Keywords: black holes; astrophysical black holes; galactic center; accretion
The Accuracy of the Hubble Constant Measurement Verified through Cepheid Amplitudes

The accuracy of the Hubble constant measured with extragalactic Cepheids depends on robust photometry and background estimation in the presence of stellar crowding. The conventional approach accounts for crowding by sampling backgrounds near Cepheids and assuming that they match those at their positions. We show a direct consequence of crowding by unresolved sources at Cepheid sites is a reduction in the fractional amplitudes of their light curves. We use a simple analytical expression to infer crowding directly from the light curve amplitudes of >200 Cepheids in three Type Ia supernovae hosts and NGC 4258 as observed by Hubble Space Telescope—the first near-infrared amplitudes measured beyond the Magellanic Clouds. Where local crowding is minimal, we find near-infrared amplitudes match Milky Way Cepheids at the same periods. At greater stellar densities we find that the empirically measured amplitudes match the values predicted (with no free parameters) from crowding assessed in the conventional way from local regions, confirming their accuracy for estimating the background at the Cepheid locations. Extragalactic Cepheid amplitudes would need to be ∼20% smaller than measured to indicate additional, unrecognized crowding as a primary source of the present discrepancy in H0. Rather, we find the amplitude data constrains a systematic mis-estimate of Cepheid backgrounds to be 0.029 ± 0.037 mag, more than 5× smaller than the size of the present ∼0.2 mag tension in H0. We conclude that systematic errors in Cepheid backgrounds do not provide a plausible resolution to the Hubble tension.

Keywords: cepheid distance; hubble constant; cosmology; distance indicators; ccd photometry; light curves; cepheid variable stars
Detection of a Superluminous Spiral Galaxy in the Heart of a Massive Galaxy Cluster

It is well established that brightest cluster galaxies (BCGs), residing in the centers of galaxy clusters, are typically massive and quenched galaxies with cD or elliptical morphology. An optical survey suggested that an exotic galaxy population, superluminous spiral and lenticular galaxies, could be the BCGs of some galaxy clusters. Because the cluster membership and the centroid of a cluster cannot be accurately determined based solely on optical data, we followed up a sample of superluminous disk galaxies and their environments using XMM-Newton X-ray observations. Specifically, we explored seven superluminous spiral and lenticular galaxies that are candidate BCGs. We detected massive galaxy clusters around five superluminous disk galaxies and established that one superluminous spiral, 2MASX J16273931+3002239, is the central BCG of a galaxy cluster. The temperature and total mass of the cluster are ${{kT}}_{500}={3.55}_{-0.20}^{+0.18}$ keV and M 500 = (2.39 ± 0.19) × 1014 M ⊙. We identified the central galaxies of the four clusters that do not host superluminous disk galaxies at their cores, and established that the centrals are massive elliptical galaxies. However, for two of the clusters, the offset superluminous spirals are brighter than the central galaxies, implying that the superluminous disk galaxies are the brightest cluster galaxies. Our results demonstrate that superluminous disk galaxies are rarely the central systems of galaxy clusters. This is likely because galactic disks are destroyed by major mergers, which are more frequent in high-density environments. We speculate that the disks of superluminous disk galaxies in cluster cores may have been reformed due to mergers with gas-rich satellites.

Keywords: brightest cluster galaxies; giant galaxies; x-ray astronomy; intracluster medium; high energy astrophysics; spiral galaxies; galaxy clusters; galactic and extragalactic astronomy; extragalactic astronomy
Precise Transit Photometry Using TESS: Updated Physical Properties for 28 Exoplanets around Bright Stars

The Transiting Exoplanet Survey Satellite (TESS) follow-up of a large number of known transiting exoplanets provides a unique opportunity to study their physical properties more precisely. Being a space-based telescope, the TESS observations are devoid of any noise component resulting from the interference of Earth's atmosphere. TESS also provides a greater probability to observe subsequent transit events owing to its longer uninterrupted time-series observations compared to ground-based telescopes. For the exoplanets around bright host stars in particular, TESS time-series observations provide high signal-to-noise ratio (S/N) lightcurves, which can be used for higher-precision studies for these exoplanets. In this work, I have studied the TESS transit photometric follow-up observations of 28 exoplanets around bright stars with V mag ≤ 10. The already high-S/N lightcurves from TESS have been further processed with a critical noise-treatment algorithm, using the wavelet-denoising and the Gaussian-process regression techniques, to effectively reduce the noise components, both correlated and uncorrelated in time, which were then used to estimate the physical properties of these exoplanets. The study has resulted in very precise values for the physical properties of the target exoplanets, with the improvements in precision being significant for most of the cases compared to the previous studies. Also, since a comparatively large number of transit lightcurves from TESS observations were used to estimate these physical properties for each of the target exoplanets, which removes any bias due to the lack of sufficient data sets, these updated physical properties can be considered extremely accurate and reliable for future studies.

Keywords: transit photometry; exoplanets; hot jupiters; gaussian processes regression; wavelet analysis
Be It Unresolved: Measuring Time Delays from Lensed Supernovae

Gravitationally lensed Type Ia supernovae (SNe Ia) may be the next frontier in cosmic probes, able to deliver independent constraints on dark energy, spatial curvature, and the Hubble constant. Measurements of time delays between the multiple images become more incisive due to the standardized candle nature of the source, monitoring for months rather than years, and partial immunity to microlensing. While currently extremely rare, hundreds of such systems should be detected by upcoming time domain surveys. Others will have the images spatially unresolved, with the observed lightcurve a superposition of time-delayed image fluxes. We investigate whether unresolved images can be recognized as lensed sources given only lightcurve information, and whether time delays can be extracted robustly. We develop a method that we show can identify these systems for the case of lensed SNe Ia with two images and time delays exceeding ten days. When tested on such an ensemble, without microlensing, the method achieves a false-positive rate of ≲5%, and measures the time delays with a completeness of ≳93% and with a bias of ≲0.5% for Δtfit ≳ 10 days. Since the method does not assume a template of any particular type of SN, the method has the (untested) potential to work on other types of lensed SNe systems and possibly on other transients as well.

Keywords: strong gravitational lensing; type ia supernovae; astrostatistics techniques; cosmology; sky surveys; supernovae
The Solar Cycle Dependence of In Situ Properties of Two Types of Interplanetary CMEs during 1999-2020

Generally, in situ parameters of interplanetary coronal mass ejections (ICMEs) are analyzed as a whole, or ICMEs are classified by speed or whether they are with and without magnetic clouds. Zhai and colleagues found that ICMEs with and without flares can be extracted only by the average charge states of iron (Q Fe). In the present study, the ICMEs are categorized into two types, flare CMEs (FCs) and nonflare CMEs (NFCs) by the Q Fe. We find that the occurrence rates of FCs and NFCs are both decreased from solar maximum to minimum. The occurrence rates and proportions of FCs are both higher in solar cycle 23 than in solar cycle 24. In contrast, the occurrence rates of NFCs are almost the same during the two solar cycles. The durations of FCs are longer than those of NFCs. The fractions of FCs and NFCs that are associated with magnetic clouds (MCs) or magnetic field direction rotation evidence are 73% and 69%, respectively. The speed, Q Fe, O7+/O6+, helium abundance (A He), and first ionization potential bias are all higher for FCs than for NFCs. The above parameters inside NFCs and solar wind are almost the same. The solar cycle dependence of the parameters inside NFCs is more clear than that inside FCs. The statistical results demonstrate that the material sources of FCs are not completely the same as those of NFCs. Part of the material inside FCs should come from the lower atmosphere where the A He is higher. The statistical results indicate that all CMEs are associated with flux ropes on the Sun.

Keywords: solar coronal mass ejections; solar flares; solar abundances
Ultradiffuse Galaxies—A Distinct Population? Dwarf Galaxies in the Coma Cluster and A262 from Deep u'–g'–r' Wendelstein Imaging Data

In this study, we compare the structural parameters of ultradiffuse galaxies (UDGs) to those of other dwarf galaxies and investigate whether UDGs form a distinct population. We observed deep $u^{\prime} $ -, $g^{\prime} $ -, and $r^{\prime} $ -band images (maximum limiting surface brightness [3σ, 10″ × 10″] $u^{\prime} $ and $g^{\prime} $ : $\approx \ 30\,\mathrm{mag}\,{\mathrm{arcsec}}^{-2}$ ; $r^{\prime} $ : $\approx \,29\,\mathrm{mag}\,{\mathrm{arcsec}}^{-2}$ ) of A1656 (Coma cluster) and A262 with the Wendelstein Wide Field Imager at the 2.1 m Fraunhofer Wendelstein Telescope at the Wendelstein Observatory. We measure $u^{\prime} -g^{\prime} $ and $g^{\prime} -r^{\prime} $ colors and structural parameters using parametric fitting of tens of thousands of potential UDGs and other dwarf galaxies. Cluster members are identified and separated from diffuse background galaxies based on red sequence membership and location in the $u^{\prime} -g^{\prime} $ versus $g^{\prime} -r^{\prime} $ color–color diagram. We find 11 UDGs in A262 and 48 UDGs in A1656. The latter is 6 times more than van Dokkum et al. found in the overlapping region. By comparing the structural parameters of UDGs to non-UDGs in our sample and to spheroidals from the literature, we do not find any separation in all tested parameter spaces. Instead, UDGs form the diffuse end of the already well-known spheroidal population and slightly extend it. Furthermore, we find that the UDG definition used by Koda et al. and Yagi et al. mainly extends the definition by van Dokkum et al. toward ordinary spheroidals.

Keywords: galaxy photometry; low surface brightness galaxies; dwarf galaxies; dwarf spheroidal galaxies; galaxies; galaxy structure; galaxy evolution; galaxy clusters; coma cluster; extragalactic astronomy; abell clusters
Simultaneous Estimation of Large-scale Structure and Milky Way Dust Extinction from Galaxy Surveys

The high cosmological precision offered by the next generation of galaxy surveys hinges on improved corrections for Galactic dust extinction. We explore the possibility of estimating both the dust extinction and large-scale structure from a single photometric galaxy survey, making use of the predictable manner in which Milky Way dust affects the measured brightness and colors of galaxies in a given sky location in several redshift bins. To test our method, we use a synthetic catalog from a cosmological simulation designed to model the Vera C. Rubin Observatory Legacy Survey of Space and Time. At high Galactic latitude (∣b∣ ≳ 20°) and a resolution of 1° ( $7^{\prime} $ ), we predict the uncertainty in the measurement of dust extinction, E(B - V), to be 0.005 mag (0.015 mag). This is similar to the uncertainty of existing dust maps, illustrating the feasibility of our method. Simultaneous estimation of large-scale structure is predicted to recover the galaxy overdensity δ with a precision of ~0.01 (~0.05) at 1° ( $7^{\prime} $ ) resolution. We also introduce a Bayesian formalism that combines prior information from existing dust maps with the likelihood of Galactic dust extinction determined from the excursion of observed galaxy properties.

Keywords: astronomical methods; interstellar dust extinction; galaxy properties; large-scale structure of the universe
Off-axis Afterglow Closure Relations and Fermi-LAT Detected Gamma-Ray Bursts

Gamma-ray bursts (GRBs) are one of the most promising transient events for studying multiwavelength observations in extreme conditions. Observation of GeV photons from bursts would provide crucial information on GRB physics, including the off-axis emission. The Second Gamma-ray Burst Catalog (2FLGC) has been announced by the Fermi Large Area Telescope (Fermi-LAT) Collaboration. This catalog includes 29 bursts with photon energy higher than 10 GeV. While the synchrotron forward-shock model has well explained the afterglow data of GRBs, photon energies greater than 10 GeV are very difficult to interpret within this framework. To study the spectral and temporal indices of those bursts described in 2FLGC, Fraija et al. (2022a) proposed the closure relations (CRs) of the synchrotron self-Compton (SSC) emission of GRBs emitted from an on-axis jet, which decelerates in stellar-wind and constant-density medium. In this paper, we extend the CRs of the SSC afterglow from an on-axis scenario to an off-axis scenario, including the synchrotron afterglow radiation that seems to be off-axis. In order to investigate the spectral and temporal index evolution of those bursts reported in 2FLGC, we consider hydrodynamical evolution with energy injection in the adiabatic and radiative regimes for an electron distribution with a spectral index of 1 < p < 2 and 2 < p. The results show that the most likely scenario for synchrotron emission corresponds to the stellar wind whether or not there is energy injection and that the most likely scenario for SSC emission corresponds to the constant density when there is no energy injection and to the stellar wind when there is energy injection.

Keywords: gamma-ray bursts; non-thermal radiation sources; magnetic fields
Four Years of Type Ia Supernovae Observed by TESS: Early-time Light-curve Shapes and Constraints on Companion Interaction Models

We present 307 type Ia supernova (SN) light curves from the first 4 yr of the Transiting Exoplanet Survey Satellite mission. We use this sample to characterize the shapes of the early-time light curves, measure the rise times from first light to peak, and search for companion star interactions. Using simulations, we show that light curves must have noise <10% of the peak flux to avoid biases in the early-time light-curve shape, restricting our quantitative analysis to 74 light curves. We find that the mean power-law index ${t}^{{\beta }_{1}}$ of the early-time light curves is β 1 = 1.93 ± 0.57, and the mean rise time to peak is 15.7 ± 3.5 days. The underlying population distribution for β 1 may instead consist of a Gaussian component with mean 2.29, width 0.34, and a long tail extending to values less than 1.0. We find that the data can rarely distinguish between models with and without companion interaction models. Nevertheless, we find three high-quality light curves that tentatively prefer the addition of a companion interaction model, but the statistical evidence for the companion interactions is not robust. We also find two SNe that disfavor the addition of a companion interaction model to a curved power-law model. Taking the 74 SNe together, we calculate 3σ upper limits on the presence of companion signatures to control for orientation effects that can hide companions in individual light curves. Our results rule out common progenitor systems with companions having Roche lobe radii >31 R ⊙ (separations >5.7 × 1012 cm, 99.9% confidence level) and disfavor companions having Roche lobe radii >10 R ⊙ (separations >1.9 × 1012 cm, 95% confidence level). Lastly, we discuss the implications of our results for the intrinsic fraction of single degenerate progenitor systems.

Keywords: type ia supernovae
Whistler Waves and Electron Properties in the Inner Heliosphere: Helios Observations

We present the analysis of narrowband whistler wave signatures observed in the inner heliosphere (0.3-1 au). These signatures are bumps in the spectral density in the 10-200 Hz frequency range of the AC magnetic field as measured by the search coil magnetometer on board the Helios 1 spacecraft. We show that the majority of whistler signatures are observed in the slow solar wind (<500 km s-1) and their occurrence increases with the radial distance (R), from ∼3% at 0.3 au to ∼10% at 0.9 au. In the fast solar wind (>600 km s-1), whistler activity is significantly lower; whistler signatures start to appear for R > 0.6 au and their number increases from ∼0.03% at 0.65 au to ∼1% at 0.9 au. We have studied the variation of the electron core and halo anisotropy (Te⊥/Te∥), as well as the electron normalized heat flux as a function of R and of the solar wind speed. We find that, in the slow wind electron core and halo anisotropy is higher than in fast one, and also that these anisotropies increase radially in both types of winds, which is in line with the occurrence of whistler signatures. We hypothesize the existence of a feedback mechanism to explain the observed radial variations of the occurrence of whistlers in relation with the halo anisotropy.

Keywords: solar wind; interplanetary magnetic fields
Molecular Clouds in the Second Quadrant of the Milky Way Midplane from l = 104°75 to l = 119°75 and b = -5°25 to b = 5°25

In this work, we study the properties of molecular clouds in the second quadrant of the Milky Way Midplane, from l = 104°75 to l = 119°75, and b = -5°25 to b = 5°25, using the 12CO, 13CO, and C18O J = 1 - 0 emission line data from the Milky Way Imaging Scroll Painting project. We identify 857 and 300 clouds in the 12CO and 13CO spectral cubes, respectively, using the DENDROGRAM + SCIMES algorithms. The distances of the molecular clouds are estimated, and physical properties such as the mass, size, and surface densities of the clouds are tabulated. The molecular clouds in the Perseus Arm are about 30-50 times more massive, and 4-6 times larger than the clouds in the Local Arm. This result, however, is likely to be biased by distance selection effects. The surface densities of the clouds are enhanced in the Perseus Arm, with an average value of ∼100 M⊙ pc-2. Here. we select the 40 most extended (>0.35 arcdeg2) molecular clouds from the 12CO catalog to build the H2 column density probability distribution function (N-PDF). Some 78% of the N-PDFs of the selected molecular clouds are well fitted with log-normal functions with only small deviations at high densities, corresponding to star-forming regions with scales of ∼1-5 pc in the Local Arm, and ∼5-10 pc in the Perseus Arm. About 18% of the selected molecular clouds have power-law N-PDFs at high densities. In these molecular clouds, the majority of the regions fitted with the power law correspond to molecular clumps at sizes of ∼1 pc, or filaments at widths of ∼1 pc.

Keywords: interstellar medium; interstellar clouds; molecular clouds; star formation; surveys