Progenitors and ejected companions of thermonuclear supernovae

• Applicant: Professor Dr. Stephan Geier
• Subject Area: Astrophysics and Astronomy
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 508160303

Despite the global importance of thermonuclear supernovae type Ia (SN Ia) for astrophysics and cosmology, neither their progenitors nor the exact explosion mechanisms are known. Several progenitor classes, all involving an accreting white dwarf (WD), have been proposed. However, only very few objects fullfilling the predicted criteria have been discovered. Among them WD binaries with helium star (hot subdwarf) companions stand out, because four good progenitor candidates for two possible SN scenarios and also candidates for the surviving and subsequently ejected companions of such explosions have been discovered. Here we propose a project to study both the progenitor and the ejected companion populations of SN Ia involving He-stars to put constraints on the explosion mechanism and assess the contribution of those channels to the observed Galactic SN Ia rate.

• DFG Programme: Research Grants