We examine a possible supergroup in the direction of the Eridanus constellation using 6dF Galaxy Survey second data release ( 6dFGS DR2 ) positions and velocities together with 2MASS and HyperLEDA photometry .
We perform a friends-of-friends analysis to determine which galaxies are associated with each substructure before examining the properties of the constituent galaxies .
The overall structure is made up of three individual groups that are likely to merge to form a cluster of mass \sim 7 \times 10 ^ { 13 } M _ { \odot } .
We conclude that this structure is a supergroup .
We also examine the colours , morphologies and luminosities of the galaxies in the region with respect to their local projected surface density .
We find that the colours of the galaxies redden with increasing density , the median luminosities are brighter with increasing environmental density and the morphologies of the galaxies show a strong morphology-density relation .
The colours and luminosities of the galaxies in the supergroup are already similar to those of galaxies in clusters , however the supergroup contains more late-type galaxies , consistent with its lower projected surface density .
Due to the velocity dispersion of the groups in the supergroup , which are lower than those of clusters , we conclude that the properties of the constituent galaxies are likely to be a result of merging or strangulation processes in groups outlying this structure .