Early-type galaxies in the Antlia Cluster: global properties
  We present an extension of our previous research on the early-type galaxy
population of the Antlia cluster (d ~ 35 Mpc), achieving a total coverage of ~
2.6 deg x deg and performing surface photometry for ~300 galaxies, 130 of which
are new uncatalogued ones. Such new galaxies mainly fall in the low surface
brightness (LSB) regime, but there are also some lenticulars (S0) which support
the existence of unique functions that connect bright and dwarf galaxies in the
scaling relations. We analyse the projected spatial distribution of galaxies up
to a distance of ~800 kpc from NGC 3268, the adopted centre, as well as the
radial velocity distribution and the correlation between galaxy colour and
effective radius with the projected spatial distribution. We also obtain the
luminosity function of the early-type galaxies and the distribution of stellar
masses using the T1-band magnitudes and adopted mass-luminosity ratios.
Additionally, we correlate the central galaxy distribution with an X-ray
emission map from the literature. Based on the analysis of the radial
velocities and galaxy colour distributions, we find that galaxies redder than
the colour-magnitude relation (CMR) have a velocity distribution strongly
concentrated towards the values of the dominant galaxies and are homogeneously
distributed throughout the cluster. Those bluer than the CMR, in turn, have a
much more extended radial velocity distribution and are concentrated towards
the centre of the cluster. We also identify 12 candidates to ultra diffuse
galaxies (UDG), that seem to be split into two families, and speculate about
their origins in the context of the cluster structure.
