EDP Sciences
Free access
Volume 386, Number 3, May II 2002
Page(s) 775 - 783
Section Cosmology
DOI http://dx.doi.org/10.1051/0004-6361:20020271

A&A 386, 775-783 (2002)
DOI: 10.1051/0004-6361:20020271

Abundance and evolution of galaxy clusters in cosmological models with massive neutrino

N. A. Arhipova1, T. Kahniashvili2, 3 and V. N. Lukash1

1  Astro Space Center of P.N. Lebedev Physical Institute, Moscow, Russia
2  Center for Plasma Astrophysics, Abastumani Astrophysical Observatory, Tbilisi, Georgia
3  Department of Physics and Astronomy, Rutgers University, Piscataway, NJ, USA

(Received 3 August 2001 / Accepted 11 January 2002 )

The time evolution of the number density of galaxy clusters and their mass and temperature functions are used to constrain cosmological parameters in the spatially flat dark matter models containing hot particles (massive neutrino) as well as cold and baryonic matter. We test the modified MDM ( $\Lambda =0$) models with cosmic gravitational waves and show that they neither pass the cluster evolution test nor reproduce the observed height of the first acoustic peak in $\Delta T/T$ spectrum, and therefore should be ruled out. The models with a non-zero cosmological constant are in better agreement with observations. We estimate the free cosmological parameters in $\Lambda$MDM with a negligible abundance of gravitational waves, and find that within the parameter ranges $h\in~(0.6, 0.7)$, $n\in (0.9, 1.1)$, $f_\nu\equiv\Omega_\nu /\Omega_{\rm m}\in (0, 0.2)$, (i) the value of $\Omega_\Lambda$ is strongly affected by a small fraction of hot dark matter: $\;0.45 <\Omega_\Lambda <0.7\;$ ( $1\sigma$ CL), and (ii) the redshift evolution of galaxy clusters alone reveals the following explicit relation between $\Omega_\Lambda$ and $f_\nu$: $\Omega_\Lambda +0.5f_\nu =0.65\pm 0.1.$ This degeneracy is also expected in LSS tests (with a smaller error). The present accuracy of observational data allows to bound the fraction of hot matter, $f_\nu\in (0, 0.2)$; the number of massive neutrino species remains undelimited, $N_\nu =1, 2, 3$.

Key words: cosmology: observations -- cosmology: theory -- large-scale structure of the Universe --  of 

Offprint request: N. A. Arhipova, arna@lukash.asc.rssi.ru

© ESO 2002