NoSOCS in SDSS. V. Red Disc and Blue Bulge Galaxies Across Different
  Environments
  We investigated the typical environment and physical properties of "red
discs" and "blue bulges", comparing those to the "normal" objects in the blue
cloud and red sequence. Our sample is composed of cluster members and field
galaxies at $z \le 0.1$, so that we can assess the impact of the local and
global environment. We find that disc galaxies display a strong dependence on
environment, becoming redder for higher densities. This effect is more
pronounced for objects within the virial radius, being also strong related to
the stellar mass. We find that local and global environment affect galaxy
properties, but the most effective parameter is stellar mass. We find evidence
for a scenario where "blue discs" are transformed into "red discs" as they grow
in mass and move to the inner parts of clusters. From the metallicity
differences of red and blue discs, and the analysis of their star formation
histories, we suggest the quenching process is slow. We estimate a quenching
time scale of $\sim $ 2$-$3 Gyr. We also find from the sSFR$-$M$_*$ plane that
"red discs" gradually change as they move into clusters. The "blue bulges" have
many similar properties than "blue discs", but some of the former show strong
signs of asymmetry. The high asymmetry "blue bulges" display enhanced recent
star formation compared to their regular counterparts. That indicates some of
these systems may have increased their star formation due to mergers.
Nonetheless, there may not be a single evolutionary path for these blue
early-type objects.
