Non-Gaussian morphology on large scales: Minkowski functionals of the REFLEX cluster catalogue

¹ Sektion Physik, Ludwig-Maximilians-Universität, Theresienstraße 37, 80333 München, Germany
² Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218, USA
³ Max-Planck-Institut für Metallforschung, Heisenbergstr. 1, 70569 Stuttgart, Germany
⁴ Institut für Theoretische und Angewandte Physik, Fakultät für Physik, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
⁵ Max-Planck-Institut für Extraterrestrische Physik, PO Box 1603, Giessenbachstrasse 1, 85740 Garching, Germany
⁶ Osservatorio Astronomico di Brera, Merate, Italy
⁷ Liverpool John Moores University, Liverpool, UK
⁸ Navel Research Laboratory, Washington DC, USA

Corresponding author: M. Kerscher, Kerscher@theorie.physik.uni-muenchen.de

Received: 11 May 2001
Accepted: 20 July 2001

Abstract

In order to quantify higher-order correlations of the galaxy cluster distribution we use a complete family of additive measures which give scale-dependent morphological information. Minkowski functionals can be expressed analytically in terms of integrals of n-point correlation functions. They can be compared with measured Minkowski functionals of volume limited samples extracted from the Reflex survey. We find significant non-Gaussian features in the large-scale spatial distribution of galaxy clusters. A Gauss-Poisson process can be excluded as a viable model for the distribution of galaxy clusters at the significance level of 95% .