Nature and distribution of dark matter: 2. Binaries, groups and clusters

Vasanthi, M. M. ; Padmanabhan, T. (1989) Nature and distribution of dark matter: 2. Binaries, groups and clusters Journal of Astrophysics and Astronomy, 10 (4). pp. 425-432. ISSN 0250-6335

[img]
Preview
PDF - Publisher Version
438kB

Official URL: http://www.ias.ac.in/jarch/jaa/10/425-432.pdf

Related URL: http://dx.doi.org/10.1007/BF02715076

Abstract

We study the mass-radius relationship for aggregates of galaxies, viz. binaries, small groups and clusters. The data are subjected to a simple best-fit analysis similar to the one carried out earlier for individual field galaxies. The analysis shows that: (i) The data on binary galaxies are consistent with the assumption that binaries are just two galaxies, each with an individual isothermal (M∝R) dark matter halo, moving under the mutual gravitational attraction, (ii) The data on the groups of galaxies are too scattered to obey a single power-law relation of the form M = kRn with any degree of reliability, (iii) The data on groups and clusters fit better with a law of the formM = AR3 +BR. This form suggests the existence of two components in dark matter-one which is clustered around the galaxies (M∝R) and another which is distributed smoothly (M∝R3). The smooth distributions becomes significant only at scales ≥ 1 Mpc and hence does not affect binaries significantly. We briefly discuss the theoretical implications of this analysis.

Item Type:Article
Source:Copyright of this article belongs to Indian Academy of Sciences.
Keywords:Galaxies; Dark Matter; Galaxies; Binary; Galaxies; Clusters
ID Code:72463
Deposited On:29 Nov 2011 05:24
Last Modified:18 May 2016 17:42

Repository Staff Only: item control page