Time-delay effect on the cosmic background radiation by static gravitational potential of clusters
Jul, 2000Citations per year
Abstract: (arXiv)
We present a quantitative analysis of the time-delay effect on the cosmic background radiation (CBR) by static gravitational potential of galaxy clusters. This is primarily motivated by growing observational evidence that clusters have essentially experienced no-evolution since redshift , indicating that the contribution of a time-dependent potential to CBR anisotropy discussed in literature could be rather small for the dynamically-relaxed clusters. Using the softened isothermal sphere model and the universal density profile for the mass distribution of rich clusters, we calculate the CBR anisotropy by the time-delay effect and compare it with those generated by the thermal and kinematic S-Z effects as well as by the transverse motion of clusters. While it is unlikely that the time-delay effect is detectable in the current S-Z measurement because of its small amplitude of - and its achromaticity, it nevertheless leads to an uncertainty of in the measurement of the kinematic S-Z effect of clusters. Future cosmological application of the peculiar velocity of clusters to be measured through the S-Z effect should therefore take this uncertainty into account.References(22)
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