Origin of the Galactic bulge Two red clumps (RCs) observed in the color–magnitude diagram of the Milky Way bulge are widely accepted as evidence for an X-shaped structure that originated from the bar instability. A drastically different interpretation has been suggested, however, based on the He-enhanced multiple stellar population phenomenon as is observed in globular clusters (GCs). [read more]

CANYVAL-C (CubeSat Astronomy NASA and Yonsei using Virtual ALignment for Coronagraph) mission It is a technology demonstration mission that shows the concept of a virtual space telescope for solar science mission by using two CubeSats. This mission is aimed to take images of solar corona via formation flying. To accomplish the goal of this mission, two CubeSat systems and the ground station have been developed. The two CubeSats will be launched in early 2020.

Multi-wavelength research of the A115 cluster A115 is a merging galaxy cluster at z ∼ 0.2 with a number of remarkable features, including a giant (∼2.5 Mpc)radio relic, two asymmetric X-ray peaks with trailing tails, and a peculiar line-of-sight velocity structure. We present a multiwavelength study of A115 using optical imaging data from Subaru, X-ray data from Chandra, and spectroscopic data from the Keck/DEIMOS and MMT/Hectospec instruments. [read more]