Institute of Astronomy

Final Structure and Fate of Massive Stars: the Impact of Mass Loss by Winds and Roche-lobe Overflow

SpeakerTalk DateTalk Series
Mathieu Renzo29 July 2016Binary Stars Talks

Abstract

Massive stars experience mass loss by stellar winds and as result of interaction with a binary companion. Both modes of mass loss, steady and episodic, have major impact on the final stellar structure. This can change the final fate and leaves imprints on the supernova lightcurve. To quantify the impact, we carry out a systematic study of mass loss algorithms using the MESA stellar evolutionary code. We employ a very extensive nuclear reaction network (~200 isotopes) and adopt ultra high resolution (10-100 times more mesh points than previously published models). We find this is crucial to resolve the delayed effect of mass loss on the final core structure.

Our results show that main sequence winds have the largest effect on the final core structure, even though they only remove a small fraction of the total mass. The predicted final total mass for a given star is uncertain by a factor 2 due to uncertainties in the stellar wind algorithms. The compactness, which has been suggested to be indicative of whether a massive star leaves a neutron star or black hole, is affected at least 30%.  We further discuss the impact of impulsive removal of large fraction of the envelope on the light curve morphology, peak luminosity, and duration.  We conclude that our current understanding of stellar mass loss constitutes a limiting factor in the study of supernova explosions."

Presentation