The Fornax Deep Survey with VST. V. Exploring the faintest regions of
  the bright early-type galaxies inside the virial radius
  This paper is based on the multi-band (ugri) Fornax Deep Survey (FDS) with
the VLT Survey Telescope (VST). We study bright early-type galaxies (m_B<15
mag) in the 9 square degrees around the core of the Fornax cluster, which
covers the virial radius. The main goal of the present work is to provide the
analysis of the light distribution for all galaxies out to unprecedented limits
(in radius and surface brightness) and to release the main products resulting
from this analysis in all FDS bands. From the isophote fit, we derive the
azimuthally averaged surface brightness profiles, the position angle and
ellipticity profiles as a function of the semi-major axis. In each band, we
derive the total magnitudes, effective radii, integrated colors and stellar
mass-to-light ratios. The long integration times, the arcsec-level angular
resolution of OmegaCam@VST and the large covered area of FDS allow us to map
the light and color distributions out to large galactocentric distances (up to
about 10-15 R_e) and surface brightness levels beyond mu_r = 27 mag/arcsec^2
(mu_B > 28 mag/arcsec^2). Therefore, the new FDS data allow us to explore in
great detail the morphology and structure of cluster galaxies out to the region
of the stellar halo. The observations suggest that the Fornax cluster is not
completely relaxed inside the virial radius. The bulk of the gravitational
interactions between galaxies happens in the W-NW core region of the cluster,
where most of the bright early-type galaxies are located and where the
intra-cluster baryons (diffuse light and GCs) are found. We suggest that the
W-NW sub-clump of galaxies results from an infalling group onto the cluster,
which has modified the structure of the galaxy outskirts (making asymmetric
stellar halos) and has produced the intra-cluster baryons (ICL and GCs),
concentrated in this region of the cluster.
