Large scale correlations in galaxy clustering from the two degree field galaxy redshift survey

¹ Institute of Astronomy, St. Petersburg State University, Staryj Peterhoff, 198504 St. Petersburg, Russia
² “Enrico Fermi Center”, Via Panisperna 89 A, Compendio del Viminale, 00184 Rome, Italy e-mail: sylos@roma1.infn.it
³ “Istituto dei Sistemi Complessi” CNR, via dei Taurini 19, 00185 Rome, Italy

Received: 25 July 2005
Accepted: 5 October 2005

Abstract

We study galaxy correlations from samples extracted from the 2dFGRS final release. Statistical properties are characterized by studying the nearest neighbor probability density, the conditional density and the reduced two-point correlation function. The result is that the conditional density has a power-law behavior in redshift space described by an exponent  ± 0.2 in the interval from about 1 Mpc/h, the average distance between nearest galaxies, up to about 40 Mpc/h, corresponding to radius of the largest sphere contained in the samples. These results are consistent with other studies of the conditional density and are useful to clarify the subtle role of finite-size effects on the determination of the two-point correlation function in redshift and real space.