Central galaxies in different environments: Do they have similar
  properties?
  We perform an exhaustive comparison among central galaxies from SDSS catalogs
in different local environments at 0.01<=z<=0.08. The central galaxies are
separated into two categories: group centrals (host halos containing
satellites) and field centrals (host halos without satellites). From the
latter, we select other two subsamples: isolated centrals and bright field
centrals, both with the same magnitude limit. The stellar mass (Ms)
distributions of the field and group central galaxies are different, which
explains why in general the field central galaxies are mainly located in the
blue cloud/star forming regions, whereas the group central galaxies are
strongly biased to the red sequence/passive regions. The isolated centrals
occupy the same regions as the bright field centrals since both populations
have similar Ms distributions. At parity of Ms, the color and specific star
formation rate (sSFR) distributions of the samples are similar, specially
between field and group centrals. Furthermore, we find that the stellar-to-halo
mass (Ms-Mh) relation of isolated galaxies does not depend on the color, sSFR
and morphological type. For systems without satellites, the Ms-Mh relation
steepens at high halo masses compared to group centrals, which is a consequence
of assuming a one-to-one relation between group total stellar mass and halo
mass. Under the same assumption, the scatter around the Ms-Mh relation of
centrals with satellites increases with halo mass. Our results suggest that the
mass growth of central galaxies is mostly driven by the halo mass, with
environment and mergers playing a secondary role.
