Morphological fluctuations of large-scale structure: The PSCz survey

¹ Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218, USA
² Sektion Physik, Ludwig-Maximilians-Universität, Theresienstraße 37, 80333 München, Germany
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 Teoretisk Astrofysik Center, Juliane Maries Vej 30, 2100 København Ø, Denmark
⁶ Theoretical Astrophysics Division, National Astronomical Observatory, 2-21-1 Osawa Mitaka, Tokyo 181-8588, Japan
⁷ Département de Physique Théorique, Université de Genève, 24 quai E. Ansermet, 1211 Genève, Switzerland

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

Received: 15 January 2001
Accepted: 24 April 2001

Abstract

In a follow-up study to a previous analysis of the IRAS 1.2 Jy catalogue, we quantify the morphological fluctuations in the PSCz survey. We use a variety of measures, among them the family of scalar Minkowski functionals. We confirm the existence of significant fluctuations that are discernible in volume-limited samples out to 200h^-1 Mpc. In contrast to earlier findings, comparisons with cosmological N-body simulations reveal that the observed fluctuations roughly agree with the cosmic variance found in corresponding mock samples. While two-point measures, e.g. the variance of count-in-cells, fluctuate only mildly, the fluctuations in the morphology on large scales indicate the presence of coherent structures that are at least as large as the sample.