Normal type Ia supernovae from disruptions of hybrid He-CO white-dwarfs by CO white-dwarfs

Understand

Type Ia supernovae (SNe) are thought to originate from the thermonuclear explosions of carbon-oxygen (CO) white dwarfs (WDs).

• The proposed progenitors of standard type Ia SNe have been studied for decades and can be, generally, divided into explosions of CO WDs accreting material from stellar non-degenerate companions (single-degenerate; SD models), and those arising from the explosive interaction of two CO WDs (double-degenerate; DD models).
• However, current models for the progenitors of such SNe fail to reproduce the diverse properties of the observed explosions, nor do they explain the inferred rates and the characteristics of the observed populations of type Ia SNe and their expected progenitors.
• Here we show that the little-studied mergers of CO-WDs with hybrid Helium-CO (He-CO) WDs can provide for a significant fraction of the normal type Ia SNe.