2007 Fiscal Year Final Research Report Summary
Search for dark baryon in the universe using oxygen emission lines in soft X-ray band
| Project/Area Number |
16340053
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Astronomy
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| Research Institution | The University of Tokyo |
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Principal Investigator |
SUTO Yasushi The University of Tokyo, Department of Physics, Professor (90183053)
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| Co-Investigator(Kenkyū-buntansha) |
TARUYA Atsushi The University of Tokyo, Department of Physics, Assistant Professor (40334239)
OHASHI Takaya Tokyo Metropolitan University, Department of Physics, Professor (70183027)
SASAKI Shin Tokyo Metropolitan University, Department of Physics, Assistant Professor (80262260)
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| Project Period (FY) |
2004 – 2007
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| Keywords | astrophysics / X-ray astronomy / dark baryon / cluster of galaxies / soft X-ray spectroscopy / gamma-ray burst |
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| Research Abstract |
1) We developed and ran a cosmological hydro-code with our German collaborator, Dr. Klaus Dolag. The code takes account of a variety of physical processes including radiative cooling, star formation, gas heating due to supernovae, chemical evolution.
2) Using the above simulation results, we constructed a mock galaxy catalog in the Local Universe, and discussed the detection feasibility of WHIM (warm-hot intergalactic medium) associated with outskirts of nearby galaxy clusters via oxygen emission lines (Yoshikawa et al. 2004).
3) We also studied the detection feasibility of absorption lines of WHIM using the background quasars and X-ray after glow of gamma-ray bursts (Kawahara et al. 2006).
4) It has been pointed out that the element abundance in WHIM does not obey the ionization equilibrium. We followed the time evolution of the oxygen ionization states using the simulation data, and indeed showed that the ionization equilibrium is not valid in WHIM. We found that the intensity ratio of oxygen lines in different ionization states is a good indicator of the departure from the ionization equilibrium (Yoshikawa and Sasaki 2006).
5) We proposed a new empirical analytic model for temperature and density inhomogeneities in intra-cluster medium, and showed that this nice explains the observation data of galaxy cluster A3667 from Chandra X-ray satellite (kawahar et al.2007,2008).
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[Book] 一般相対論入門2005
Author(s)
須藤靖
Total Pages
186
Publisher
日本評論社
Description
「研究成果報告書概要(和文)」より
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