NoSOCS in SDSS. IV. The Role of Environment Beyond the Extent of Galaxy
  Clusters
  We are able to extend the investigation of the
color-morphology-density-radius relations, for bright and faint galaxies, to $R
\gtrsim 3 \times R_{200}$ and to very low density regions, probing the
transition region between cluster and field galaxies, and finding a smooth
variation between these two populations. We investigate the environmental
variation of galaxy properties (and their relations), such as color, spectral
type and concentration. Our sample comprises 6,415 galaxies that were
previously selected as cluster members from 152 systems with $z \le 0.100$. Our
main findings are: (i) The fraction of discs is generally higher than the ones
for blue and star-forming galaxies, indicating a faster transformation of color
and star-formation compared to structural parameters. (ii) Regarding the
distance to the cluster center we find a small variation in the galaxy
populations outside the virial radius. Once within that radius the fractions of
each population change fast, decreasing even faster within $R \sim 0.3 \times
R_{200}$. (iii) We also find a small increase in the fraction of blue faint
galaxies within $R \sim 0.4 \times R_{200}$, before decreasing again to the
most central bin. (iv) Our results do not indicate a significant dependence on
cluster mass, except for the disc fraction in the core of clusters. (v) The
relations between galaxy properties also point to no dependence on cluster
mass, except for the scatter of the color stellar mass relation. Our results
corroborate a scenario on which pre-processing in groups leads to a strong
evolution in galaxy properties, before they are accreted by large clusters
(abridged).
