Environments of galaxies in groups within the supercluster-void network
  Majority of all galaxies reside in groups of less than 50 member galaxies.
These groups are distributed in various large-scale environments from voids to
superclusters. Evolution of galaxies is affected by the environment in which
they reside. Our aim is to study the effects that the local group scale and the
supercluster scale environment have on galaxies. We use a luminosity-density
field to determine density of the large-scale environment of galaxies in groups
of various richness. We calculate fractions of different types of galaxies in
groups with richnesses up to 50 member galaxies and in different large-scale
environments from voids to superclusters. The fraction of passive elliptical
galaxies rises and the fraction of star-forming spiral galaxies declines when
the richness of a group of galaxies rises from two to approximately ten
galaxies. On the large scale, the passive elliptical galaxies become more
numerous than star-forming spirals when the environmental density grows to the
density level typical for superclusters. The large-scale environment affects
the level of these fractions in groups: galaxies in equally rich groups are
more likely to be elliptical in supercluster environments than in lower
densities. The crossing point, where the number of passive and star-forming
galaxies is equal, happens in groups with lower richness in superclusters than
in voids. Galaxies in low-density areas require richer groups to evolve from
star-forming to passive. Groups in superclusters are on average more luminous
than groups in large-scale environments with lower density. Our results suggest
that the evolution of galaxies is affected by both, by the group in which the
galaxy resides, and by its large-scale environment. Galaxies in lower-density
regions develop later than galaxies in similar mass groups in high-density
environments.
