The 91̽»¨-Dartmouth Thirty Degree Survey I: Observations and Calibration of a Wide-Field Multi-Band Survey
(2004)
Substructure Analysis of Selected Low Richness 2dFGRS Clusters of Galaxies
(2004)
The nature of the relative bias between galaxies of different spectral type in 2dFGRS
(2004)
Galaxy groups in the 2dFGRS: The group-finding algorithm and the 2PIGG catalogue
Monthly Notices of the Royal Astronomical Society 348:3 (2004) 866-878
Abstract:
The construction of a catalogue of galaxy groups from the Two-degree Field Galaxy Red-shift Survey (2dFGRS) is described. Groups are identified by means of a friends-of-friends percolation algorithm which has been thoroughly tested on mock versions of the 2dFGRS generated from cosmological N-body simulations. The tests suggest that the algorithm groups all galaxies that it should be grouping, with an additional 40 per cent of interlopers. About 55 per cent of the ∼190 000 galaxies considered are placed into groups containing at least two members of which ∼29 000 are found. Of these, ∼7000 contain at least four galaxies, and these groups have a median redshift of 0.11 and a median velocity dispersion of 260 km s-1. This 2dFGRS Percolation-Inferred Galaxy Group (2PIGG) catalogue represents the largest available homogeneous sample of galaxy groups. It is publicly available on the World Wide Web.Galaxy Ecology: groups and low density environments in the SDSS and 2dFGRS
Monthly Notices of the Royal Astronomical Society 348 (2004) 1355-1372