H
0 from an orientation-unbiased sample of Sunyaev–Zel'dovich and X-ray clusters |
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| Authors: | Michael E Jones Alastair C Edge Keith Grainge William F Grainger Rüdiger Kneissl G G Pooley Richard Saunders Shigeru J Miyoshi Taisuke Tsuruta Koujun Yamashita Yuzuru Tawara Akihiro Furuzawa Akihiro Harada Isamu Hatsukade |
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| Institution: | Astrophysics Group, Cavendish Laboratory, Madingley Road, Cambridge CB3 0HE;Department of Physics, South Road, Durham DH1 3LE;Department of Physics, Kyoto Sangyo University, Kamigamo-Motoyama, Kita-ku, Kyoto 603-8555, Japan;Department of Astrophysics, Faculty of Science, Nagoya University, Chikusa-ku, Nagoya 464-0814, Japan;Faculty of Engineering, Miyazaki University, 1-1 Gakuen-kibanadai-nishi, Miyazaki 889-2192, Japan |
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| Abstract: | We have observed the Sunyaev–Zel'dovich (SZ) effect in a sample of five moderate-redshift clusters with the Ryle Telescope, and used them in conjunction with X-ray imaging and spectral data from ROSAT and ASCA to measure the Hubble constant. This sample was chosen with a strict X-ray flux limit using both the Bright Cluster Sample and the Northern ROSAT All-Sky Survey (RASS) cluster catalogues to be well above the surface brightness limit of the RASS, and hence to be unbiased with respect to the orientation of the cluster. This controls a major potential systematic effect in the SZ/X-ray method of measuring H 0. Taking the weighted geometric mean of the results and including the main sources of error, namely the noise in the SZ measurement, the uncertainty in the X-ray temperatures and the unknown ellipticity and substructure of the clusters, we find H 0= 59+10?9 (random)+8?7(systematic) km s?1 Mpc?1 assuming a standard cold dark matter model with ΩM= 1.0, ΩΛ= 0.0 or H 0= 66+11?10 +9?8 km s?1 Mpc?1 if ΩM= 0.3, ΩΛ= 0.7 . |
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| Keywords: | galaxies: clusters: general cosmic microwave background cosmology: observations distance scale X-rays: general |
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