The Rate of Supernovae at Redshift 0.1 − 1.0 : the Stockholm VIMOS Supernova Survey IV

We present supernova rate measurements at redshift 0.1–1.5 from the Stockholm VIMOS Supernova Survey (SVISS). The sample contains 16 supernovae in total. The discovered supernovae have been classified into core collapse or thermonuclear (Ia) types based on their light curves, colour evolution and host galaxy photometric redshift. The rates we find for the core collapse supernovae are 1.25 (+2.27 +0.85 −0.97 −0.78) - with statistical and systematic errors, respectively - at z = 0.39 and 6.90 (+5.24 +3.04 −3.25 −2.14) at z = 0.73. For the Ia supernovae the rates are 2.02 (+1.57 +0.53−0.96 −0.57) at z = 0.39 and 1.03 (+0.92 +0.31−0.54 −0.36) at z = 0.80. All of these rate estimates have been corrected for host galaxy extinction. Using Monte Carlo simulations we make a thorough study of the systematic effects from assumptions made when calculating the rates and find that the most important errors comes from misclassification, the assumed mix of faint and bright supernova types and uncertainties in redshift. We compare our rates to other observations, to the star formation history for core collapse rates and to different models of the delay time distribution for Ia rates. Overall, our measurements agree quite well with these other rates when using redshift-dependent corrections for extinction. We do not find any evidence of a missing fraction of core collapse supernovae.
Author count:10