Physical conditions and element abundances in supernova and γ-ray burst host galaxies at different redshifts

We compare the physical parameters and the relative abundances calculated throughout supernova (SN) and gamma-ray burst (GRB) host galaxies using a detailed modelling of the spectra. The coupled effect of shocks and radiation from the starburst within the host galaxy is considered. We have found the following. (i) Shock velocities are lower in long-period GRBs (LGRBs) than in SN host galaxies. (ii) O/H relative abundances in SN hosts are scattered within a range 8.0 < 12+log(O/H) < 8.85 but they are close to solar in LGRB hosts. LGRB galaxies hosting Wolf-Rayet stars have He/H = 0.13 in a few objects. (iii) The starburst temperatures within a few SN hosts are relatively high (T-* > 10(5) K). The values of T-* in LGRB hosts are similar to 3-8 x 10(4) K. (iv) The H alpha absolute flux calculated from the emitting clouds of a few SN hosts at 0.1 < z < 0.3 is sensibly higher than in the other galaxies. H alpha increases sharply with the ionization parameter U. The present analysis suggests that the SN-host symbiosis is stronger than for GRBs in terms of activity. The physical and chemical conditions in the GRB host galaxies are similar to those in starburst galaxies within a large redshift range.