Physical pairs: a way station on the road of coalescence of poor groups

Our knowledge of galaxy evolution in a hierarchical evolutionary scenariorequires understanding of progressively poorer structures. Poor/loose groupsrepresent the defining galaxy aggregates in the field and are probably closelyconnected to physical pairs as well as to isolated E galaxies. We propose to observe a sample of mixed morphology physical pairs, isolated or in poor environments in the Southern hemispere. Systems span a wide range of impactparameters, indicative of different stages/kinds of galaxy encounters in thefield. Our specific aim is to reach a definition of the evolutionary state ofthe pair/loose group, which could be closely linked to their Xray properties. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]