Statistical Analysis of High Redhisft Galaxy Clusters

2014 Fiscal Year Final Research Report

• Project/Area Number: 23740144
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Astronomy
• Research Institution: National Astronomical Observatory of Japan (2013-2014); The University of Tokyo (2011-2012)
• Principal Investigator: TANAKA Masayuki 国立天文台, ハワイ観測所, 特任助教 (50589207)
• Project Period (FY): 2011-04-28 – 2015-03-31
• Keywords: 銀河団 / 銀河形成・進化

Outline of Final Research Achievements

The formation and evolution of galaxies are dependent on environments within large-scale structure. In order to understand physical processes driving the environment-dependent galaxy evolution, we aim to perform a statistical analysis of distant galaxy clusters. We searched for distant clusters by using both X-ray and optical-nearIR data and confirmed a low-mass cluster of galaxies at 9.5 billion years ago. This cluster is likely a progenitor of today's cluster of typical mass, but interestingly, the cluster is dominated by quiescent early-type galaxies. We also studied a proto-cluster located at 10.5 billion years ago and our results hint at an accelerated formation of cluster galaxies. These results suggest that environments play an important role since an early phase of galaxy formation and evolution.

Free Research Field

銀河形成・進化