Early-type galaxies in the Antlia Cluster: global properties

CALDERÓN, JUAN P; BASSINO, LILIA P; CELLONE, SERGIO A; GÓMEZ, MATÍAS; CASO, JUAN P

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2020 vol. 497 p. 1791 - 1806

0035-8711

We present an extension of our previous research on the early-type galaxy population of theAntlia cluster (d ∼ 35 Mpc), achieving a total coverage of ∼ 2.6 deg^2 and performing surfacephotometry for ∼ 300 galaxies, 130 of which are new uncatalogued ones. Such new galaxiesmainly 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 thescaling 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 thecorrelation 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 stellarmasses using the T1-band magnitudes and adopted mass-luminosity ratios. Additionally, wecorrelate 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 thatgalaxies redder than the colour-magnitude relation (CMR) have a velocity distribution stronglyconcentrated towards the values of the dominant galaxies and are homogeneously distributedthroughout the cluster. Those bluer than the CMR, in turn, have a much more extended radialvelocity distribution and are concentrated towards the centre of the cluster. We also identify12 candidates to ultra diffuse galaxies (UDG), that seem to be split into two families, andspeculate about their origins in the context of the cluster structure.