Institute of Astronomy

A Common-envelope Wind Model for SNe Ia

SpeakerTalk DateTalk Series
Xiangcun Meng29 July 2016Binary Stars Talks

Abstract

We propose a new version of the SD model in which a common envelope (CE) is assumed
to form when the mass-transfer rate between the CO WD and its companion exceeds a critical accretion rate, instead of the onset of an optically thick wind (OTW). In this case, the WD may
gradually increase its mass at the base of the CE similar to the degenerate core in an asymptotic giant branch star. Due to a large nuclear luminosity for stable hydrogen burning, the CE may
expand to giant dimensions and will lose mass from the surface of the CE by a CE wind (CEW), which leads to a low density in the CE and a correspondingly low frictional luminosity between the binary system and the CE. As a result, the binary system will, within a large parameter range, avoid a strong spiral-in phase and finally re-emerge from the CE phase rather than merge completely.

Presentation