Forum Springer Astron. Astrophys.
Forum Whats New Search Orders

Astron. Astrophys. 333, 809-812 (1998)

Table of Contents
Available formats: HTML | PDF | (gzipped) PostScript

Count laws and projection effects in clusters of galaxies *

C. Adami 1, P. Amram 2 and G. Comte 2

1 IGRAP, Laboratoire d'Astronomie Spatiale, Marseille, France
2 IGRAP, Observatoire de Marseille, France

Received 18 August 1997 / Accepted 17 February 1998


We show that a 2D projection is representative of its corresponding 3D distribution at a confidence level of 90 % if it follows a King profile and if we consider the whole spatial distribution. The level is significantly lower and not decisive in the vicinity of the 2D cluster center. On the other hand, if we verify the reciprocal statement of the Mattig's distribution (1958) -i.e. a flux limited sample is represented by a 0.6 slope of its count law-, we point out that, due to the usual inaccuracy of the slope determination, a slope of 0.6 is not a sufficiently strict criterion for completeness and uniformity of a sample as often used in the literature.

Key words: galaxies: clusters: general – large-scale structure of Universe

* Based on observations collected at the ESO (La Silla, Chile) and CFHT

Send offprint requests to: C. Adami

© European Southern Observatory (ESO) 1998

Online publication: April 28, 1998