2003 Fiscal Year Final Research Report Summary
Observation of Fluctuation of Cosminc Background Radiation
| Project/Area Number |
13304013
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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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 | Ibaraki University |
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Principal Investigator |
TSUOI Masato IBARAKI UNIV., College of Science, Assoc.Prof., 理学部, 助教授 (10202186)
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| Co-Investigator(Kenkyū-buntansha) |
YOKOSAWA Masayoshi IBARAKI Univ., College of Science, Prof., 理学部, 教授 (30158357)
KJASUGA Takashi Hosei Univ., College of Eng., Prof., 工学部, 教授 (70126027)
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| Project Period (FY) |
2001 – 2003
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| Keywords | CBR / Hubble cosntant / cosmological constant / S-Z Effect |
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| Research Abstract |
1)We have built a portable interferometer at 220 GHz for observation of fluctuation of cosmic background radiation. This system was not yet completed for some technical problems. First, the noise level of the IF amplifiers which are located in the SIS mixer is still high although that of the prototype amplifier is quite low. Second, the stability of the local oscillator is not sufficient, which strongly depends on the temperature in the receiver room.
2)We have performed the ON-OFF observation of the S-Z effect toward eight X-ray bright galaxy clusters from z=0.18 to 0355 at 43 GHz using S40M as a pilot survey. The S-Z effects were detected for all clusters as temperature decrement of 0.5-1mK at the center. The Hubble constant is estimated to be H_0=64±17km.s.Mpc for a flat ΛCDM cosmology, which shows good agreement with the values by other S-Z effect observations. The mapping Observations of S-Z effect are on-going. Although most of the observed images are roughly described by the isothermal spherical β-model density distribution, the deviation from the model seems to be large for the clusters with the irregularity in the X-ray image rather than those without it.
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