Effects of environment on stellar metallicity profiles of late-type
  galaxies in the CALIFA survey
  We explore the effects of environment in the evolution of late-type galaxies
by studying the radial profiles of light- and mass-weighted metallicities of
galaxies in two discrete environments: field and groups. We use a sample of 167
late-type galaxies, with stellar masses $9\le \log(M_{\star}/M_{\odot}) \le
12$, drawn from the CALIFA survey. We make a study of the metallicity of
galaxies in these two environments which includes the comparison of the
metallicity as a function of the radius, at a characteristic scale, and as a
function of a the stellar mass surface density. We find significant differences
between group and field late-type galaxies in terms of their metallicity, in
the sense that group galaxies are systematically more metallic than their field
counterparts. We find that field galaxies have, in general, metallicity
profiles that show a negative gradient in their inner regions, and a shallower
profile at larger radii. This contrasts with the metallicity profiles of
galaxies in groups, which tend to be flat in the inner regions, and to have a
negative gradient in the outer parts. Regarding the metallicity at the
characteristic radius of the luminosity profiles, we consistently find that it
is higher for group galaxies irrespective of galaxy mass. At fixed local
stellar surface mass density, group galaxies are again more metallic, also the
dependence of metallicity on surface density is less important for group
galaxies. The evidence of a clear difference on the metallicity of group and
field galaxies, as a function of mass, spatial scale, and local stellar mass
density, are indicative of the different evolutionary paths that galaxies in
groups and in the field have followed. We discuss possible implications of the
observed differences.
