Are galaxy interactions linked to enhanced star formation

From the apparent magnitude-limited main galaxy sample of the Sloan Digital Sky Survey Data Release 7 (SDSS DR7), we construct a paired galaxy sample and an isolated galaxy sample, and compare the star formation rate (SFR) and the specific star formation rate (SSFR) of paired galaxies with those of isolated galaxies. It is found that isolated galaxies preferentially have higher SFR and SSFR than paired galaxies. We also investigate the dependence of the SFR and SSFR on the three-dimensional separation between two members of pairs, but do not find evidence for the dependence of SFR enhancement on this separation.