Revealing the ICM physics by joint analysis of SZ effect and X-ray imaging with high angular resolutions

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K04012
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 16010:Astronomy-related
• Research Institution: Hiroshima University
• Principal Investigator: Okabe Nobuhiro 広島大学, 先進理工系科学研究科(理), 准教授 (00436073)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 銀河団 / 銀河団ガス / スニヤエフ・ゼルドビッチ効果 / X線 / 弱い重力レンズ効果 / 多波長ジョイント解析

Outline of Final Research Achievements

We carried out the study based on both observational and theoretical approaches. In the observational approach, a joint SZ effect and X-ray analysis was performed using one to three spherically symmetric gas models. The multi-wavelength analysis, including weak gravitational lensing masses and optical imaging data, was also carried out for three clusters, allowing a quantitative assessment of the merger boost with respect to the merger timescale. In the theoretical approach, an analytical model was developed for numerical simulations of galaxy clusters colliding on the celestial plane. The Rankine-Hugoniot relation describing the shock was introduced into the gNFW model describing the galaxy cluster gas distribution. We found that it simultaneously reconstruct the overall gas distribution and the local shock structure.

Free Research Field

銀河団

Academic Significance and Societal Importance of the Research Achievements

銀河団は宇宙最大の天体であり、その衝突現象はエネルギーを最も開放する。これの詳細な物理の解明は、宇宙の構造形成を理解するのに重要であると同時に、今後の望遠鏡や衛星計画と密接に関係する。特に高角度分解能SZ効果の観測装置の技術進歩は、銀河団ガスの研究に大きな革命を引き起こす。そのため研究の舗装整備は必要不可欠である。また、一連の研究を通して、プレスリリースを行い、社会的還元を行った。