Connections between galaxy mergers and Starburst: evidence from local
  Universe
  Major mergers and interactions between gas-rich galaxies with comparable
masses are thought to be the main triggers of starburst. In this work, we
study, for a large stellar mass range, the interaction rate of the starburst
galaxies in the local universe. We focus independently on central and satellite
star forming galaxies extracted from the Sloan Digital Sky Survey. Here the
starburst galaxies are selected in the star formation rate (SFR) stellar mass
plane with SFR five times larger than the median value found for "star forming"
galaxies of the same stellar mass. Through visual inspection of their images
together with close companions determined using spectroscopic redshifts, we
find that ~50% of the "starburst" populations show evident merger features,
i.e., tidal tails, bridges between galaxies, double cores and close companions.
In contrast, in the control sample we selected from the normal star forming
galaxies, only ~19% of galaxies are associated with evident mergers. The
interaction rates may increase by ~5% for the starburst sample and 2% for the
control sample if close companions determined using photometric redshifts are
considered. The contrast of the merger rate between the two samples strengthens
the hypothesis that mergers and interactions are indeed the main causes of
starburst.
