Mass profiles and galaxy orbits in nearby galaxy clusters from the analysis of the projected phase-space - Astrophysics > Cosmology and Nongalactic AstrophysicsReport as inadecuate




Mass profiles and galaxy orbits in nearby galaxy clusters from the analysis of the projected phase-space - Astrophysics > Cosmology and Nongalactic Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: We analyze kinematic data of 41 nearby z<0.1 relaxed galaxy clusters interms of the projected phase-space density using a phenomenological, fullyanisotropic model of the distribution function. We apply the Markov Chain MonteCarlo approach to place constraints on total mass distribution approximated bythe universal NFW profile and the profile of the anisotropy of galaxy orbits.We find the normalization of the mean mass-concentration relation isc=6.9 {-0.7}^{+0.6} at the virial mass M v=5x10^{14}M sun. Assuming aone-to-one correspondence between sigma 8 and the normalization of themass-concentration relation in the framework of the concordance model weestimate the normalization of the linear power spectrum to besigma 8=0.91 {-0.08}^{+0.07}. Our constraints on the parameters of the massprofile are compared with estimates from other methods. We show that galaxyorbits are isotropic at the cluster centres with the mean ratio of theradial-to-tangential velocity dispersions sigma r-sigma theta=0.97+-0.04 andradially anisotropic at the virial sphere with the mean ratiosigma r-sigma theta=1.75^{+0.23} {-0.19}. Although the value of the centralanisotropy appears to be universal, the anisotropy at the virial radius differsbetween clusters within the range 1


Author: Radoslaw Wojtak, Ewa L. Lokas

Source: https://arxiv.org/







Related documents