The Type Ia Supernova rate in the local Universe

Current measurements of the Type Ia Supernova (SNIa) rate, as determined by standard astronomical methods, are in reasonable agreement with measurements of the cosmic star formation rate combined with simple models for SNIa progenitors. However, systematic uncertainties still undermine a precise determination of the SNIa rate. Recent models of these systematics, combined with new measurements, indicate that the local SNIa rate may be a factor ∼4 higher than previous determinations. This result, if true, would have interesting implications for many areas of astronomy and SNIa physics. Here, I will examine some of these implications, focusing in particular on the prospects for MeV gamma ray astronomy. Additionally, since SNIa are believed to produce at least half of the iron abundance in the Universe, I discuss how a new high SNIa rate could alleviate the tension between the observed and predicted iron abundance. Finally, I combine this new rate with measurements of the SNIa radial distribution in local galaxies and positron escape in SNIa to update predictions for positron production in the Milky Way bulge, concluding that median estimates make SNIa a strong candidate to account for the observed INTEGRAL signal.