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Precise Mass, Orbital Motion, and Stellar Properties of the M-dwarf Binary LP 349‑25AB
Curiel, Salvador; Ortiz-León, Gisela N.; Mioduszewski, Amy J. +1 more
LP 349‑25 is a well-studied close stellar binary system comprised of two late M dwarf stars, where both stars are close to the limit between star and brown dwarf. This system was previously identified as a source of gigahertz radio emission. We observed LP 349‑25AB over 11 epochs in 2020–2022, detecting both components in this nearby binary system…
Temporally Resolved Type III Solar Radio Bursts in the Frequency Range 3–13 MHz
Maksimovic, Milan; Kontar, Eduard P.; Chrysaphi, Nicolina +2 more
Radio observations from space allow to characterize solar radio bursts below the ionospheric cutoff, which are otherwise inaccessible, but suffer from low, insufficient temporal resolution. In this Letter we present novel, high-temporal resolution observations of type III solar radio bursts in the range 3–13 MHz. A dedicated configuration of the R…
Investigating 56 High Galactic Latitude Open Cluster Candidates in Gaia DR3
Chen, Jing; Zhang, Su; Wu, You +4 more
Using Gaia DR3 data, we revisit 56 high Galactic latitude (∣b∣ ≥ 30°) open cluster (OC) candidates with poor shapes of color–magnitude diagrams (CMDs), including unclear and paired main sequences (MSs). We aim to confirm their physical reality and explore whether the special MS morphology is intrinsic to genuine OCs. Initially, we redetermine clus…
Assessment of SDSS-derived Galaxy Morphologies Using HST Imaging
Salim, Samir; Osborne, Chandler
The Sloan Digital Sky Survey (SDSS) was foundational to the study of galaxy evolution, having revealed the bimodality of galaxies and the relationship between their structure and star-forming activity. However, ground-based optical surveys like SDSS are limited in resolution and depth, which may lead to biases or poor quality in the derived morpho…
Massive Quiescent Disk Galaxies at 0.5 ≤ z ≤ 1 in CANDELS: Color Gradients and Likely Origin
Cui, Qifan; Liu, F. S.; Zhao, Pinsong
A rare population of massive disk-dominated quiescent galaxies has recently drawn much attention, which intrudes the red sequence (RS) population without destroying the underlying stellar disks. In this study, we have carefully identified 48 RS, disk-dominated galaxies with M * > 1010 M ⊙ between redshift 0.5 an…
Period–Luminosity–Metallicity–Color Relations of Late-type Contact Binaries in the Big Data Era
Tian, Zhi-Jia; Song, Lian-Yun
Binary stars ubiquitous throughout the Universe are important. Contact binaries (CBs) possessing period–luminosity (PL) relations could be adopted as distance tracers. The PL relations of CBs are influenced by metallicity abundance and color index, which are connected to both the radius and luminosity of stars. Here we propose fine relations of th…
A New Cosmic-Ray Rejection Routine for HST WFC3/UVIS via Label-free Training of deepCR
Williams, Benjamin F.; Zhang, Keming; Durbin, Meredith +1 more
deepCR is a deep-learning-based cosmic-ray (CR) rejection framework originally presented by Zhang & Bloom. The original approach requires a dedicated training set that consists of multiple frames of the same fields, enabling automatic CR labeling through comparison with their median coadds. Here, we present a novel training approach that circu…
CHARA Near-infrared Imaging of the Yellow Hypergiant Star ρ Cassiopeiae: Convection Cells and Circumstellar Envelope
Gies, Douglas R.; Monnier, John D.; Schaefer, Gail H. +18 more
Massive evolved stars such as red supergiants and hypergiants are potential progenitors of Type II supernovae, and they are known for ejecting substantial amounts of matter, up to half their initial mass, during their final evolutionary phases. The rate and mechanism of this mass loss play a crucial role in determining their ultimate fate and the …
DESI Massive Poststarburst Galaxies at z ∼ 1.2 Have Compact Structures and Dense Cores
Miquel, Ramon; Sanchez, Eusebio; Bezanson, Rachel +34 more
Poststarburst galaxies (PSBs) are young quiescent galaxies that have recently experienced a rapid decrease in star formation, allowing us to probe the fast-quenching period of galaxy evolution. In this work, we obtained Hubble Space Telescope (HST)/WFC3 F110W imaging to measure the sizes of 171 massive (
Integrated Study of X-Ray Spectrum and Time Lags for HBL Mrk 421 within the Framework of the Multiple-zone Leptonic Model
Xiao, Guang-Cheng; Hu, Wen; Kang, Jia-Lai +3 more
We present the timing analysis of 10 archived XMM-Newton observations with an exposure of >40 ks of Markarian 421. Mrk 421 is the brightest high-frequency-peaked BL Lac object emitting in X-rays produced by electrons accelerated in the innermost regions of a relativistic jet pointing toward us. For each observation, we construct averaged X-ray …