X-ray spectroscopic study of cluster gas dynamics

2014 Fiscal Year Final Research Report

• Project/Area Number: 24540243
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Astronomy
• Research Institution: Japan Aerospace Exploration Agency
• Principal Investigator: TAMURA Takayuki 独立行政法人宇宙航空研究開発機構, 宇宙科学研究所, 助教 (00370099)
• Co-Investigator(Renkei-kenkyūsha): HAYASHIDA Kiyoshi 大阪大学, 理学部, 准教授 (30222227) ; KITAYAMA Tetsu 東邦大学, 理学部, 教授 (00339201)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 銀河団 / X線観測 / 暗黒物質

Outline of Final Research Achievements

Galaxy clusters are the largest and youngest gravitationally-bound cosmic structure. As the structure forms, gravitational potential governed by dark matter pulls and thus heats the ICM through shocks. Gas bulk or turbulent motions can be measured directly using the Doppler shift or by broadening of X-ray line emissions. However, the limited energy resolutions of current X-ray instruments continues to hinder such measurements. In order to measure the ICM gas dynamics directly, we observed the Perseus and other clusters with Suzaku. A hint of gas bulk motion, with radial velocity relative to the main system was found at west of the cluster center, where an X-ray excess and a cold front were found previously. No other velocity structure was discovered. These results of gas dynamics in the core and larger scales in association with cluster merger activities are discussed and future potential of high-energy resolution spectroscopy with ASTRO-H is considered.

Free Research Field

宇宙物理学