Search Publications
Tracing the Galactic Disk with the Kinematics of Gaia Cepheids
Wang, Shu; Deng, Licai; Chen, Xiaodian +1 more
Classical Cepheids (CCs) are excellent tracers for understanding the structure of the Milky Way disk. The latest Gaia Data Release 3 provides a large number of line-of-sight velocity information for Galactic CCs, offering an opportunity for studying the kinematics of the Milky Way. We determine the 3D velocities of 2057 CCs relative to the Galacti…
Scylla. III. The Outside-in Radial Age Gradient in the Small Magellanic Cloud and the Star Formation Histories of the Main Body, Wing, and Outer Regions
McQuinn, Kristen B. W.; Dolphin, Andrew E.; Murray, Claire E. +13 more
The proximity of the Large and Small Magellanic Clouds (LMC and SMC) provides the opportunity to study the impact of dwarf–dwarf interactions on their mass assembly with a unique level of detail. To this end, we analyze two-filter broadband imaging of 83 Hubble Space Telescope (HST) pointings covering 0.203 deg2 toward the SMC, extendin…
Modeling ALMA Observations of the Warped Molecular Gas Disk in the Red Nugget Relic Galaxy NGC 384
Ho, Luis C.; Gebhardt, Karl; Barth, Aaron J. +9 more
We present 0.″22 resolution CO(2–1) observations of the circumnuclear gas disk in the local compact galaxy NGC 384 with the Atacama Large Millimeter/submillimeter Array (ALMA). While the majority of the disk displays regular rotation with projected velocities rising to 370 km s‑1, the inner ∼0.″5 exhibits a kinematic twist. We develop w…
Comparison of the On-disk Apparent Current Sheets with the Limb Ones
Zhang, Jun; Ding, Tao
Based on observations from the Solar Dynamics Observatory (SDO) and the Solar and Heliospheric Observatory (SOHO), we investigate 30 apparent current sheets during 1999–2021, including 10 on-disk and 8 limb ones from the SDO, as well as 12 limb ones from the SOHO. Each on-disk current sheet is formed among an X-type configuration consisting of two…
The 3D Kinematics of the Orion Nebula Cluster. II. Mass-dependent Kinematics of the Inner Cluster
Lu, Jessica R.; Kim, Dongwon; Hsu, Chih-Chun +3 more
We present the kinematic analysis of 246 stars within $4^{\prime} $ from the center of Orion Nebula Cluster (ONC), the closest massive star cluster with active star formation across the full mass range, which provides valuable insights in the formation and evolution of star cluster on an individual-star basis. High-precision radial velocities and …
Radial Distribution of Electron Quasi-thermal Noise in the Outer Heliosphere
Chen, Ling; Li, Yi-Lun; Wu De, Jin
Voyager 1 and 2 are only the two spacecraft that have arrived and passed through the heliospheric boundaries. Based on the plasma data from the Voyager 2 spacecraft, the electron quasi-thermal noise (QTN) is investigated by using of the electron population model consisting of a core with Maxwellian distribution and a halo with kappa distribution. …
Protoplanetary Disks around Sun-like Stars Appear to Live Longer When the Metallicity is Low
Hirschauer, Alec S.; Fahrion, Katja; Lenkić, Laura +17 more
Previous Hubble Space Telescope observations of the star-forming cluster NGC 346 in the Small Magellanic Cloud (SMC) revealed a large population of pre-main-sequence (PMS) candidates, characterized by Hα excess emission in their photometry. However, without access to spectroscopy, the nature of these objects remained unclear. Using the NIRSpec ins…
Energetic Electrons Accelerated and Trapped in a Magnetic Bottle above a Solar Flare Arcade
Krucker, Säm; Chen, Bin; Yu, Sijie +6 more
Where and how flares efficiently accelerate charged particles remains an unresolved question. Recent studies revealed that a "magnetic bottle" structure, which forms near the bottom of a large-scale reconnection current sheet above the flare arcade, is an excellent candidate for confining and accelerating charged particles. However, further unders…
A Detailed Survey of the Parallel Mean Free Path of Solar Energetic Particle Protons and Electrons
Ruffolo, D.; Dresing, N.; Bandyopadhyay, R. +4 more
In this work, more than a dozen solar energetic particle (SEP) events are identified where the source region is magnetically well connected to at least one spacecraft at 1 au. The observed intensity–time profiles, for all available proton and electron energy channels, are compared to results computed using a numerical one-dimensional SEP transport…
JWST Photometry of Globular Clusters in A2744. II. Luminosity and Color Distributions
Harris, William E.; Reina-Campos, Marta
Deep JWST imaging of the giant galaxy cluster A2744, at redshift z = 0.308, is used to explore the features of its rich population of globular clusters (GCs), building on our initial survey of the system. We use the photometry of more than 10,000 GCs over a 3 mag range to construct the GC luminosity function and color distribution. These results n…