Supernova rates from the SUDARE VST-Omegacam search II. Rates in a
  galaxy sample
  This is the second paper of a series in which we present measurements of the
Supernova (SN) rates from the SUDARE survey. In this paper, we study the trend
of the SN rates with the intrinsic colours, the star formation activity and the
mass of the parent galaxies. We have considered a sample of about 130000
galaxies and a SN sample of about 50 events. We found that the SN Ia rate per
unit mass is higher by a factor of six in the star-forming galaxies with
respect to the passive galaxies. The SN Ia rate per unit mass is also higher in
the less massive galaxies that are also younger. These results suggest a
distribution of the delay times (DTD) less populated at long delay times than
at short delays. The CC SN rate per unit mass is proportional to both the sSFR
and the galaxy mass. The trends of the Type Ia and CC SN rates as a function of
the sSFR and the galaxy mass that we observed from SUDARE data are in agreement
with literature results at different redshifts. The expected number of SNe Ia
is in agreement with the observed one for all four DTD models considered both
in passive and star-forming galaxies so we can not discriminate between
different progenitor scenarios. The expected number of CC SNe is higher than
the observed one, suggesting a higher limit for the minimum progenitor mass. We
also compare the expected and observed trends of the SN Ia rate with the
intrinsic U - J colour of the parent galaxy, assumed as a tracer of the age
distribution. While the slope of the relation between the SN Ia rate and the U
- J color in star-forming galaxies can be reproduced well by all four DTD
models considered, only the steepest of them is able to account for the rates
and colour in star-forming and passive galaxies with the same value of the SN
Ia production efficiency.
