Investigation of High Energy Phenomena in Merging Galaxy Clusters with Numerical Simulations and X-ray Observations

2009 Fiscal Year Self-evaluation Report

• Project/Area Number: 19740096
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Single-year Grants
• Research Field: Astronomy
• Research Institution: Yamagata University
• Principal Investigator: TAKIZAWA Motokazu Yamagata University, 理学部, 准教授 (70323160)
• Project Period (FY): 2007 – 2010
• Keywords: 理論天文学 / X線天文学 / 数値シミュレーション

Research Abstract

銀河団は宇宙で最大スケールの天体で、様々な手段で観測可能な宇宙論的構造形成の現場として重要な天体である。本研究計画では、高空間分解能数値シミュレーションと「すざく」衛星によるX線観測という二つの手段を用いて、衝突銀河団の高エネルギー現象に迫ることを目的とし、以下のような点を明らかにしていきたい。N体+流体シミュレーションにより、衝突銀河団での衝撃波や乱流の構造を明らかにする。N体+電磁流体シミュレーションにより、銀河団内磁場の進化を明らかにする。とくに衝撃波や乱流に付随して特徴的な構造が現れるかと、ダイナモによる磁場の増幅過程を重点的に調べたい。すざく衛星によるX線観測から、銀河団からの非熱的硬X線を検出し(もしくは信頼度の高い上限値を付け)、銀河団内での高エネルギー粒子および磁場の存在量を決定する(もしくは信頼度の高い制限をつける)。上記のシミュレーションおよびX線観測結果、さらには各種の粒子加速モデルとの比較を行い、銀河団での高エネルギー現象の包括的なシナリオを確立する。

Research Products

• [Journal Article] Suzaku Observation of Abell 1689: Anisotropic Temperature and Entropy Distributions Associated with the Large-Scale Structure (2010)
  • Author(s): Madoka Kawaharada, Nobuhiro Okabe, Keiichi Umetsu, Motokazu Takizawa, Kyoko Matsushita, Yasushi Fukazawa, Takashi Hamana, Satoshi Miyazaki, Kazuhiro Nakazawa, Takaya Ohashi
  • Journal Title: The Astrophysical Journal 713(に掲載決定(印刷中))
  • Peer Reviewed
• [Journal Article] Suzaku Observation of the Radio Halo Cluster Abell 2319: Gas Dynamics and Hard X-ray Properties (2009)
  • Author(s): Chika Sugawara, Motokazu Takizawa, Kazuhiro Nakazawa
  • Journal Title: Publications of the Astronomical Society of Japan 61 Pages: 1293-1303
  • Peer Reviewed
• [Journal Article] Hard X-ray Properties of the Merging Cluster Abell 3667 as Observed with Suzaku (2009)
  • Author(s): Kazuhiro Nakazawa, Craig L. Sarazin, Madoka Kawaharada, Takao Kitaguchi, Sho Okuyama, Kazuo Makishima, Naomi Kawano, Yasushi Fukazawa, Susumu Inoue, Motokazu Takizawa, Daniel R. Wik, Alexis Finoguenov, Tracy E. Clarke
  • Journal Title: Publications of the Astronomical Society of Japan 61 Pages: 339-355
  • Peer Reviewed
• [Journal Article] N-body + Magnetohydrodynamical Simulations of Merging Clusters of Galaxies: Characteristic Magnetic Field Structures Generated by Bulk Flow Motion (2008)
  • Author(s): Motokazu Takizawa
  • Journal Title: The Astrophysical Journal 687 Pages: 951-958
  • Peer Reviewed
• [Journal Article] Suzaku Observation of the Ophiuchus Galaxy Cluster: One of the Hottest Cool Core Clusters (2008)
  • Author(s): Yutaka Fujita, Kiyoshi Hayashida, Masaaki Nagai, Susumu Inoue, Hironori Matsumoto, Nobuhiro Okabe, Thomas. H. Reiprich, Craig L. Sarazin, Motokazu Takizawa
  • Journal Title: Publications of the Astonomical Society of Japan 60 Pages: 1133-1142
  • Peer Reviewed
• [Presentation] Suzaku Observation of the Radio Halo Cluster Abell 2319: Hard X-ray Prope rties and Gas Dynamics (2009)
  • Author(s): Takizawa, M., Sugawara, C., Nakazawa K.
  • Organizer: The Energetic Cosmos: from Suzaku to Astro-H
  • Place of Presentation: Otaru, Japan
  • Year and Date: 20090629-20090702
• [Presentation] Magnetic Field Structures in Merging Clusters of Galaxies (2009)
  • Author(s): Motokazu Takizawa
  • Organizer: Shock Waves Turbulence, and Particle Acceleration
  • Place of Presentation: Pohang, Korea
  • Year and Date: 2009-11-21
• [Presentation] Mass Estimation of Merging Clusters of Galaxies (2008)
  • Author(s): Motokazu Takizawa, Ryo Nagino, Kyoko Matsushita
  • Organizer: The 10th Asian-Pacific Rigional Meeting o of the International Astronomical Union
  • Place of Presentation: Kunming China
  • Year and Date: 20080803-20080806
• [Remarks] 「研究会:マクロでミクロな銀河団」2007年10月24-26日たかみや瑠璃倶楽リゾート
  • URL: http://astr-www.kj.yamagata-u.ac.jp/~zao2007/