Search Publications
Solar Coronal Modeling by Path-conservative HLLEM Riemann Solver
Feng, Xueshang; Wei, Fengsi; Li, Caixia +3 more
In this paper, we employ a path-conservative HLLEM finite-volume method (FVM) to solve the solar wind magnetohydrodynamics (MHD) systems of extended generalized Lagrange multiplier (EGLM) formulation with Galilean invariance (G-EGLM MHD equations). The governing equations of single-fluid solar wind plasma MHD are advanced by using a one-step MUSCL…
Nonlinear Effects in Three-minute Oscillations of the Solar Chromosphere. II. Measurement of Nonlinearity Parameters at Different Atmospheric Levels
Chae, Jongchul; Cho, Kyuhyoun; Song, Donguk +1 more
Recent theoretical studies suggest that the nonlinearity of three-minute velocity oscillations at each atmospheric level can be quantified by the two independent parameters—the steepening parameter and the velocity amplitude parameter. For the first time, we measured these two parameters at different atmospheric levels by analyzing a set of spectr…
The Strong Gravitationally Lensed Herschel Galaxy HLock01: Optical Spectroscopy Reveals a Close Galaxy Merger with Evidence of Inflowing Gas
Marques-Chaves, Rui; Clements, David L.; Cabrera-Lavers, Antonio +15 more
The submillimeter galaxy (SMG) HERMES J105751.1+573027 (hereafter HLock01) at z = 2.9574 ± 0.0001 is one of the brightest gravitationally lensed sources discovered in the Herschel Multi-tiered Extragalactic Survey. Apart from the high flux densities in the far-infrared, it is also extremely bright in the rest-frame ultraviolet (UV), with a total a…
Current Sheets in the Wake of an Eruption of Two Crossing Filaments
Zhang, Jun; Yang, Jiayan; Li, Leping +1 more
Employing Solar Dynamic Observatory/Atmospheric Imaging Assembly (AIA) multi-wavelength images, we study an eruption of two crossing filaments, and report for the first time the current sheets (CSs) connecting the lower flare ribbons and the upper erupting filaments. On 2014 July 8, two crossing filaments are observed in the NOAA active region 121…
High-resolution Spectroscopic Abundances of Red Giant Branch Stars in NGC 6584 and NGC 7099
Chaboyer, Brian; O'Malley, Erin M.
We obtain high-resolution spectra of red giant branch stars in NGC 6584 and NGC 7099 to perform a detailed abundance analysis. We confirm cluster membership for these stars based on consistent radial velocities measured in this study and small pixel offsets between the observations of Sarajedini et al. and Piotto et al. We find mean metallicities …
Probing the Massive Star-forming Environment: A Multiwavelength Investigation of the Filamentary IRDC G333.73+0.37
Vig, S.; Mookerjea, B.; Ishwara-Chandra, C. H. +3 more
We present a multiwavelength study of the filamentary infrared dark cloud (IRDC) G333.73+0.37. The region contains two distinct mid-infrared sources S1 and S2 connected by dark lanes of gas and dust. Cold dust emission from the IRDC is detected at seven wavelength bands, and we have identified 10 high-density clumps in the region. The physical pro…
G7.7-3.7: A Young Supernova Remnant Probably Associated with the Guest Star in 386 CE (SN 386)
Vink, Jacco; Zhou, Ping; Li, Geng +1 more
Although the Galactic supernova rate is about two per century, only few supernova remnants (SNRs) are associated with historical records. There are a few ancient Chinese records of “guest stars” that are probably sightings of supernovae for which the associated SNRs are not established. Here we present an X-ray study of the SNR G7.7-3.7, as observ…
Diffuse X-Ray Emission from the Northern Arc of Loop I Observed with Suzaku
Nakashima, Shinya; Inoue, Yoshiyuki; Kataoka, Jun +4 more
After discovery of the Fermi bubbles, giant structures observed from radio to X-ray monitoring have been widely discussed as possible evidence of past activities in the Galactic center (GC). We report here on the analysis of all the Suzaku archival data pointing around the giant-scale Loop I arc. The diffuse X-ray emission from the northern Loop I…
SPIRITS 16tn in NGC 3556: A Heavily Obscured and Low-luminosity Supernova at 8.8 Mpc
Van Dyk, Schuyler D.; Smith, Nathan; Gehrz, Robert D. +17 more
We present the discovery by the SPitzer InfraRed Intensive Transients Survey (SPIRITS) of a likely supernova (SN) in NGC 3556 (M108) at only 8.8 Mpc that was not detected by optical searches. A luminous infrared (IR) transient at M [4.5] = -16.7 mag (Vega), SPIRITS 16tn is coincident with a dust lane in the inclined, star-forming disk o…
Evolution of Cometary Dust Particles to the Orbit of the Earth: Particle Size, Shape, and Mutual Collisions
Ishiguro, Masateru; Yang, Hongu
In this study, we numerically investigated the orbital evolution of cometary dust particles, with special consideration of the initial size-frequency distribution (SFD) and different evolutionary tracks according to the initial orbit and particle shape. We found that close encounters with planets (mostly Jupiter) are the dominating factor determin…