The effect of nonradial motions on the CDM model predictions
Abstract
In this paper we show how nonradial motions, originating from the tidal interaction of the irregular mass distribution within and around protoclusters, can solve some of the problems of the CDM model. Firstly the discrepancy between the CDM predicted twopoints correlation function of clusters and the observed one. We compare the twopoints correlation function, that we obtain taking account of nonradial motions, with that obtained by Sutherland & Efstathiou (1991) from the analysis of Geller & Huchra's (1988) deep redshift survey and with the data points for the APM clusters obtained by Efstathiou et al. (1992). Secondly the problem of the Xray clusters abundance overproduction predicted by the CDM model. In this case we compare the Xray temperature distribution function, calculated using PressSchechter theory and Evrard's (1990) prescriptions for the masstemperature relation, taking also account of the nonradial motions, with Henry & Arnaud (1991) and Edge et al. (1990) Xray temperature distributions for local clusters. We find that in both cases the model is in good agreement with experimental data. Finally we calculate the bias coefficient using a selection function that takes into account the effects of nonradial motions, and we show that the bias so obtained can account for a substantial part of the total bias required by observations on cluster scales.
 Publication:

New theoretical results in gravity and general relativity
 Pub Date:
 September 1999
 arXiv:
 arXiv:astroph/9811421
 Bibcode:
 1999tpgr.conf...88D
 Keywords:

 Astrophysics
 EPrint:
 24 pages Latex including 5 ps figures. Acceped for pubblication in Proceedings of " The VIII Conference on Theoretical Physics: General Relativity and Gravitation " BISTRITZA  JUNE 1518, 1998  Romania