http://arxiv.org/abs/1507.07234
We investigate dark and visible matter distribution in the Coma cluster in the case of the Navarro-Frenk-White (NFW) profile. A toy model where all galaxies in the cluster are concentrated inside a sphere of an effective radius $R_{eff}$ is considered. It enables to obtain the mean velocity dispersion as a function of $R_{eff}$. We show that, within the observation accuracy of the NFW parameters, the calculated value of $R_{eff}$ can be rather close to the observable cutoff of the galaxy distribution . Moreover, the comparison of our toy model with the observable data and simulations leads to the following preferable NFW parameters for the Coma cluster: $R_{200} \approx 1.77\,h^{-1} \, \mathrm{Mpc} = 2.61\, \mathrm{Mpc}$, $c=3\div 4$ and $M_{200}= 1.29 h^{-1}\times10^{15}M_{\odot}$. In the Coma cluster the most of galaxies are concentrated inside a sphere of the effective radius $R_{eff}\sim 3.7$ Mpc and the line-of-sight velocity dispersion is $1004\, \mathrm{km}\, \mathrm{s}^{-1}$.
R. Brilenkov, M. Eingorn and A. Zhuk
Tue, 28 Jul 15
20/70
Comments: 11 pages, 1 figure