Supernovae in isolated galaxies, in pairs and in groups of galaxies

In order to investigate the influence of the environment on the supernova (SN) production we have performed a statistical investigation of the SNe discovered in isolated galaxies, in pairs and in groups of galaxies. 22 SNe in 18 isolated galaxies, 48 SNe in 40 galaxies members of 37 pairs and 211 SNe in 170 galaxies members of 116 groups have been selected and studied. We found that the radial distributions of core-collapse SNe in galaxies located in different environments are similar, and consistent with that reported by Bartunov, Makarova & Tsvetkov (1992). SNe discovered in pairs do not privilege a particular direction with respect to the companion galaxy. Also the azimuthal distributions inside the hosts members of galaxy groups are consistent with being isotropics. The fact that SNe are more frequent in the brighter components of the pairs and groups is expected from the dependence of the SN rates on the galaxy luminosity. There is an indication that the SN rate is higher in galaxy pairs compared with that in groups. This can be related to the enhanced star formation rate in strongly interacting systems. It is concluded that, with the possible exception of strongly interacting system, the parent galaxy environment has no direct influence on the SN productio