N/O abundance ratios in gamma-ray burst and supernova host galaxies at z < 4. Comparison with AGN, starburst and H ii regions

The distribution of N/O abundance ratios calculated by the detailed modelling of different galaxy spectra at z 1 and z ~0.1 following the N/H trend and reach the characteristic N/O ratios calculated for the HII regions in local and nearby galaxies. The few short period GRB (SGRB) hosts included in the galaxy sample show N/H 8.5 many different objects are nested close to O/H solar with N/O ranging between the maximum corresponding to starburst galaxies and AGN and the minimum corresponding to HII regions and SGRB.