Letter to the Editor

Luminous superclusters: remnants from inflation?

¹ Tartu Observatory, 61602 Tõravere, Estonia
² Estonian University of Life Sciences
³ Tuorla Observatory, Väisäläntie 20, Piikkiö, Finland
⁴ Astrophysical Institute Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany
⁵ Fermi National Accelerator Laboratory, MS 127, PO Box 500, Batavia, IL 60510, USA

Received: 16 May 2006
Accepted: 24 August 2006

Abstract

Aims.We compile a supercluster sample using the Sloan Digital Sky Survey Data Release 4, and reanalyse supercluster samples found for the 2dF Galaxy Redshift Survey and for simulated galaxies of the Millennium Run.

Methods.We find for all supercluster samples Density Field (DF) clusters, which represent high-density peaks of the class of Abell clusters, and use median luminosities of richness class 1 DF-clusters to calculate relative luminosity functions.

Results.We show that the fraction of very luminous superclusters in real samples is about five times greater than in simulated samples.

Conclusions.Superclusters are generated by large-scale density perturbations that evolve very slowly. The absence of very luminous superclusters in simulations can be explained either by incorrect treatment of large-scale perturbations, or by some yet unknown processes in the very early Universe.