| Project/Area Number |
07404006
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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 |
TSUBOI Masato Ibaraki Uiversity, Faculty of Science, Associate Professor, 理学部, 助教授 (10202186)
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| Co-Investigator(Kenkyū-buntansha) |
NOGUCHI Takashi Nobeyama Radio Observatory, Associate Professor, 電波天文学研究系, 助教授 (90237826)
立松 建一 国立天文台, 電波天文学研究系, 助教授 (40202171)
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| Project Period (FY) |
1995 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥35,100,000 (Direct Cost: ¥35,100,000)
Fiscal Year 1997: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1996: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1995: ¥32,300,000 (Direct Cost: ¥32,300,000)
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| Keywords | Hubble constant / cosmological observation / receiver at mm-wave |
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| Research Abstract |
We developed a tunerless Q-band SIS mixer. The mixer is operating in the frequency range from 40 to 50 GHz with mixer bias voltage and LO power tunings. The frequency range of the mixer is available from 1 to 7 GHz. We also developed a 2*3 beam multi-feed SIS receiver for the Nobey ama 45-m telescope, in which the mixers are installed. The receiver system is designed as a sophisticated tool for the continuum mapping observation of Sunyaev-Zel'dovich effect toward clusters of galaxies. The receiver noise temperature is below 20-30 K and the instantaneous bandwidth is 700 MHz when the IF frequency is 1.5 GHz. The receiver system was located on the focal plane platform of the 45-m telescope in April 1997. In addition, the mixer was installed in the 40 GHz band VLBI receiver for the kashima 34-m telescope.
We performed a millimeter-wave pbservation of the Sunyaev-Zel'dovich effect toward a moderately distant cD cluster of galaxies, Abell, 2218, at 36 GHz using the Nobeyama 45-m telescope and a single-beam receiver. The antenna temperature decrement of the cosmic microwave background radiation (CMB) was measured be DELTAT<@D2A@>D2<@D1*@>D1 =-0.52(]SY.+-。[)0.15 mK at the central peak position of X-ray emission in the cluster. Assuming that the hot gas in the cluster has isothemality, spherical symmetry, and the beta-model density distribution, the Sunyaev-Zel'dovich effect is enferred to be DELTAT<@D2ORJ@>D2 =0.68(]SY.+-。[)0.19 mK at the Ray leigh-Jeans limit. A combination of this Sunyaev-Zel'dovich effect and X-ray surface brightness suggests that the Hubble constant is H<@D2O@>D2(q=0.5)=54<@D1+51@>D1<@D2-21@>D2kmS<@D1-1@>D1 MpS<@D1-1@>D1.
We have started the project of S-Z effect observetion with the 2*3 beam multi-feed SIS receiver and the Nobeyama 45-m telescope. Our scientific goal is reliable measurment of of S-Z effect toward many clusters. We had already observed a cluster in March 1998.
However, the weather condition was poor.
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