Search Publications
On the Roles of Stellar Rotation and Binarity in NGC 2423's Main-sequence Turnoff Region
Wang, Li; Li, Chengyuan; Bu, Yutian +2 more
Research has shown that many young and intermediate-age clusters (younger than ∼2 Gyr) have extended main sequences and extended main-sequence turnoffs (eMSTOs), which cannot be adequately described by a single isochrone. The reason for the extended main sequences is now known, with the most probable cause being the fast rotation of stars. However…
LoVoCCS. II. Weak Lensing Mass Distributions, Red-sequence Galaxy Distributions, and Their Alignment with the Brightest Cluster Galaxy in 58 Nearby X-Ray-luminous Galaxy Clusters
Cooper, M. C.; Donahue, Megan; Miyatake, Hironao +31 more
The Local Volume Complete Cluster Survey is an ongoing program to observe nearly a hundred low-redshift X-ray-luminous galaxy clusters (redshifts 0.03 < z < 0.12 and X-ray luminosities in the 0.1–2.4 keV band L X500c > 1044 erg s‑1) with the Dark Energy Camera, capturing data in the u, g, r, i, z bands wit…
Mass Assembly in Massive Star Formation: A Fragmentation Study of ATLASGAL Clumps
Wyrowski, Friedrich; Menten, Karl M.; Williams, Jonathan P. +3 more
The mass assembly in star-forming regions arises from the hierarchical structure in molecular clouds in tandem with fragmentation at different scales. In this paper, we present a study of the fragmentation of massive clumps covering a range of evolutionary states, selected from the ATLASGAL survey, using the compact configuration of the Submillime…
Asteroseismology of the Nearby K Dwarf σ Draconis Using the Keck Planet Finder and TESS
Knutson, Heather; Li, Yaguang; Lee, Chien-Hsiu +76 more
Asteroseismology of dwarf stars cooler than the Sun is very challenging owing to the low amplitudes and rapid timescales of oscillations. Here we present the asteroseismic detection of solar-like oscillations at 4-minute timescales (
The Metallicities of Five Small High-velocity Clouds
Richter, Philipp; Lockman, Felix J.; Fox, Andrew J. +5 more
High-velocity clouds (HVCs) are multiphase gas structures whose velocities (∣v LSR∣ ≥ 100 km s-1) are too high to be explained by Galactic disk rotation. While large HVCs are well characterized, compact and small HVCs (with H I angular sizes of a few degrees) are poorly understood. Possible origins for such small clouds inclu…
Axial Flux Evolution of Small-scale Magnetic Flux Ropes from 0.06 to 10 au
Wang, Haimin; Kim, Hyomin; Lee, Jeongwoo +2 more
Small-scale magnetic flux ropes (SMFRs) fill much of the solar wind, but their origin and evolution are debated. We apply our recently developed, improved Grad–Shafranov algorithm for the detection and reconstruction of SMFRs to data from Parker Solar Probe, Solar Orbiter, Wind, and Voyager 1 and 2 to detect events from 0.06 to 10 au. We observe t…
Probing the Distinct Extinction Law of the Pillars of Creation in M16 with JWST
Gao, Jian; Chen, Xi; Jiang, Biwei +2 more
Investigating the extinction law in regions of high dust extinction, such as the Pillars of Creation within the M16 region, is crucial for understanding the densest parts of the interstellar medium (ISM). In this study, we utilize observations from the Near-Infrared Camera and the Mid-Infrared Instrument onboard the James Webb Space Telescope (JWS…
The Reliability of Accretion Disk Inclination Derived from X-Ray Spectroscopy of Active Galaxies
Ho, Luis C.; Li, Ruancun; Ding, Yuanze +1 more
The inclination angle of substructures in active galaxies gives insights into physical components from scales of the vicinity of the central black hole to the entire host galaxy. We use the self-consistent reflection spectral model RELXILL to measure the inclination of the inner region of accretion disks with broadband (0.3–78 keV) X-ray observati…
Eridanus III and DELVE 1: Carbon-rich Primordial Star Clusters or the Smallest Dwarf Galaxies?
Cerny, William; Li, Ting S.; Hansen, Terese T. +8 more
We present spectroscopy of the ultra-faint Milky Way satellites Eridanus III (Eri III) and DELVE 1. We identify eight member stars in each satellite and place nonconstraining upper limits on their velocity and metallicity dispersions. The brightest star in each object is very metal poor, at [Fe/H] = ‑3.1 for Eri III and [Fe/H] = ‑2.8 for DELVE 1. …
First Direct Evidence for Keplerian Rotation in Quasar Inner Broad-line Regions
Kaspi, S.; Muñoz, J. A.; Mediavilla, E. +4 more
We introduce a novel method to derive rotation curves with light-day spatial resolution of the inner regions of lensed quasars. We aim to probe the kinematics of the inner part of the broad-line region by resolving the microlensing response—a proxy for the size of the emitting region—in the wings of the broad emission lines. Specifically, we asses…