The Core-collapse rate from the Supernova Legacy Survey

Understand

We use three years of data from the Supernova Legacy Survey (SNLS) to study the general properties of core-collapse and type Ia supernovae.

• This is the first such study using the "rolling search" technique which guarantees well-sampled SNLS light curves and good efficiency for supernovae brighter than $i^\prime\sim24$.
• Using host photometric redshifts, we measure the supernova absolute magnitude distribution down to luminosities $4.5 {\rm mag}$ fainter than normal SNIa.
• Using spectroscopy and light-curve fitting to discriminate against SNIa, we find a sample of 117 core-collapse supernova candidates with redshifts $z<0.4$ (median redshift of 0.29) and measure their rate to be larger than the type Ia supernova rate by a factor $4.5\pm0.8(stat.) \pm0.6 (sys.)$.