Flux- and volume-limited groups/clusters for the SDSS galaxies: catalogues and mass estimation^⋆

¹ Tartu Observatory, Observatooriumi 1, 61602 Tõravere, Estonia
e-mail: elmo.tempel@to.ee
² National Institute of Chemical Physics and Biophysics, Rävala pst 10, 10143 Tallinn, Estonia
³ Leibniz-Institut für Astrophysik Potsdam, an der Sternwarte 16, 14482 Potsdam, Germany
⁴ Institute of Physics, University of Tartu, 51010 Tartu, Estonia
⁵ Estonian Academy of Sciences, Kohtu 6, 10130 Tallinn, Estonia

Received: 6 February 2014
Accepted: 21 April 2014

Abstract

We provide flux- and volume-limited galaxy group and cluster catalogues based on the spectroscopic sample of the galaxies of SDSS data release 10. We used a modified friends-of-friends method with a variable linking length in the transverse and radial directions to identify as many realistic groups as possible. The flux-limited catalogue incorporates galaxies down to m_r = 17.77 mag. It includes 588 193 galaxies and 82 458 groups. The volume-limited catalogues are complete for absolute magnitudes down to M_r,lim = −18.0, −18.5, −19.0, −19.5, −20.0, −20.5, and −21.0; the completeness is achieved within different spatial volumes. Our analysis shows that flux- and volume-limited group samples are well compatible, especially for the larger groups/clusters. Dynamical mass estimates based on radial velocity dispersions and group extent in the sky were added to the extracted groups.