  We present results from a study of the NGC 4756 group which is dominated by
the elliptical galaxy NGC 5746. The characteristics of the group are
investigated through (a) the detailed investigation of the morphological,
photometric and spectroscopic properties of nine galaxies among the dominant
members of the group (b) the determination of the photometric parameters of the
faint galaxy population in an area of 34'x34' centered on NGC 4756 and (c) an
analysis of the X-ray emission in the area based upon archival data. The 9
member galaxies are located in the core part of the NGC 4756 group (a strip
diameter about 300 kpc in diameter which has a very loose configuration. The
central part of the NGC 4756 group contains a significant fraction of
early-type galaxies. Three new group members with previously unknown systemic
velocities are identified, one of which is a dE. At about 7.5' SW of NGC 4756 a
sub-structure of the group is detected, including IC 829, MCG -2-33-35, MCG
-2-33-36 and MCG -2-33-38, which meets the Hickson criteria for being a compact
group. Most of the galaxies in this sub-structure show interaction signatures.
We do not detect apparent fine structure and signatures of recent interaction
events in the early-type galaxy population, with the exception of a strong dust
lane in the elliptical MCG -2-33-38. This galaxy displays however signatures of
nuclear activity. Strong [O III], [N II] and [S II] line emission, combined
with comparatively weak, but broad H alpha emission suggest an intermediate
Seyfert type classification. Although the area is heavily contaminated by the
background cluster Abell 1631, X-ray data suggest the presence of a hot
intergalactic medium related to the group to the X-ray emission detected. The
present results are discussed in the context of group evolution.

Astrophysics