Progress in studying the typical group environment in the nearby Universe is finally enabled by the very large systematic redshift surveys of the 2dFGRS and SDSS, which have now produced large well-defined catalogues of groups, most notably the Percolation-Inferred Galaxy Group (2PIGG) catalogue which has been generated from the 2dFGRS. The latter contains nearly 225,000 redshifts of galaxies with magnitude bJ in the range 14.5-19.5 with a median redshift ~0.11, covering an area of ~1400 deg2 with a redshift completeness of 85 per cent. Together with the 5 magnitude dynamic range at a given redshift, the 2dFGRS is ideally suited for constructing a homogeneous catalogue of groups.

The 2PIGG catalogue contains systems spanning a wide range in mass and luminosity. The catalogue is so large that we not only have information on the groups themselves from the 2dFGRS data (e.g., velocity dispersions, spatial positions of members, mass, density, compactness etc.), but also on their proximity to large clusters, filaments, and voids of the large-scale structure web. The 2PIGG catalogue covers a large enough volume to be sure that is representative of the Universe as a whole, and yet contains many groups that are close enough to allow relatively detailed studies of the galaxy members. The 2PIGG is thus perfect for undertaking the study of the nearby galaxy properties as a function of the group environment.

We have been awarded an ESO Large Program (PI: M. Carollo) to study, using B and I wide-field images, the galaxy properties of a statistically complete, volume-limited sample of 185 groups extracted from the 2PIGG catalogue. Our program will image all 2PIGG groups with more than five catalogued galaxy members within the narrow redshift range 0.05 < z < 0.0585. The narrow redshift range ensures a very uniform group selection criterion and eliminates any distance related biases either in the group selection or in the observational determination of the properties of the member galaxies. The 185 groups have 2274 confirmed member galaxies, and cover a factor of 100 in group mass with about 30 groups for each octave in mass.

The particular z~0.05 redshift range was chosen because:

• The 2dFGRS magnitude limits translate at this redshift to luminosities between [M*-2] to [M*+3], meaning that the existing redshift catalogue already samples all of the luminosity function of massive galaxies and well straddles the break or bimodality in galaxy properties that has been observed in the SDSS.

• Ground-based imaging with seeing ~1'' is well suited to determine morphologies, properties of substructure such as bars, bulges and disks, and presence and properties of faint structures. It is also directly relatable to HST-resolution images of the z > 0.5 Universe (with a relative angular diameter distance of a factor 8), and will thus allow a direct comparison with HST images of galaxies in high-z groups.

• This redshift range is located just below the peak in N(z) in 2PIGG, and thus samples most of the range of group mass and luminosity that is seen in the overall 2PIGG - from the lowest mass groups up to a system with 159 members and a dynamical mass of 5 x10^14 Msol h^-1. Likewise, the groups fully cover the entire range of large-scale structure environments, with some groups residing in very dense regions and others residing in much lower density environments, allowing to study the effects of the large-scale structure on group and galaxy evolution.

• The group selection is robust and less affected by the peculiar velocities of the galaxies than is the case at lower redshifts.

• Finally, the typical scale of the groups, with r.m.s. radii of rrms ~ 4-12 arcmin, is well-suited to the half-degree FOV of the ESO wide-field camera.

We are using the ZENS optical images to establish the detailed galaxy structural and colour properties as a function of group mass, density, compactness and location respective to the large-scale structure. These are not only measures of the diversity of galaxy shapes, but also they relate to the star formation and mass assembly history of the galaxies.