A Measurement of the Rate of type-Ia Supernovae at Redshift $z\approx$ 0.1 from the First Season of the SDSS-II Supernova Survey

Understand

We present a measurement of the rate of type Ia supernovae (SNe Ia) from the first of three seasons of data from the SDSS-II Supernova Survey.

• For this measurement, we include 17 SNe Ia at redshift $z\le0.12$.
• Assuming a flat cosmology with $\Omega_m = 0.3=1-\Omega_\Lambda$, we find a volumetric SN Ia rate of $[2.93^{+0.17}_{-0.04}({\rm systematic})^{+0.90}_{-0.71}({\rm statistical})] \times 10^{-5} {\rm SNe} {\rm Mpc}^{-3} h_{70}^3 {\rm year}^{-1}$, at a volume-weighted mean redshift of 0.09.
• This result is consistent with previous measurements of the SN Ia rate in a similar redshift range.