The Multiplicity Function of Galaxies
Abstract
The multiplicity function (MF) of groups and clusters of galaxies is determined using galaxy catalogues extracted from a set of Digitized Palomar Sky Survey (DPOSS) plates. The two different types of structures (of low and high richness) were identified using two different algorithms: a modified version of the van Albada method for groups, and a peak finding algorithm for larger structures. In a 300 sq. deg. area up to z<0.2, we find 2944 groups and 179 clusters. Our MF covers a wide range of richnesses, from 2 to 200, and the two MF's derived by the two algorithms match smoothly without the need for additional conditions or normalisations. The resulting multiplicity function, of slope alpha= -2.08 +- 0.07, strongly resembles a power law.
Cite
@article{arxiv.astro-ph/0302114,
title = {The Multiplicity Function of Galaxies},
author = {E. Puddu and E. De Filippis and G. Longo and S. Andreon and R. R. Gal},
journal= {arXiv preprint arXiv:astro-ph/0302114},
year = {2009}
}
Comments
10 pages, 10 figures. Accepted by A&A