Astron. Astrophys. 319, 729-736 (1997)
Available formats: HTML | PDF | (gzipped) PostScript The anisotropy of the cosmic background radiation due to mass clustering in a closed universe ^{*}
Daming Chen ^{ 1},
Guoxuan Song ^{ 1} and
Yougen Shen ^{ 2, 1}
Received 10 June 1996 / Accepted 11 September 1996 Abstract We consider the effects on the Cosmic Background Radiation (CBR) of a single, spherically symmetric structure using the Tolman-Bondi solutions in a closed universe. The exact frequency shift of a photon passing through the center of a lump which is located between the last scattering surface and an observer is calculated. An approximate expression of the frequency shift to the first order of (the density contrast) is given. We find that there are several redshifts of the perturbing lump where the net frequency shift is zero. With increasing , the first positions of zero frequency shift move toward lower redshift; the larger the value of , the further they move. At the vicinity of the last scattering surface, where the universe is close to flat, the frequency shift will always be the same as that for a flat universe. Key words: cosmic microwave background cosmology: theory large-scale structure of the universe
* Supported by the National Natural Science Foundation of China and the Young Astronomer Laboratory of Shanghai Observatory Send offprint requests to: Daming Chen Online publication: July 3, 1998 |