Limits on core-driven ILOT outbursts of asymptotic giant branch stars

作者：Mcley Liron^*; Soker Noam

来源：Monthly Notices of the Royal Astronomical Society, 2014, 440(1): 582-587.

DOI：10.1093/mnras/stu314

• stars: AGB and post-AGB
• stars: mass-loss
• stars: variables: general

We find that single-star mechanisms for Intermediate-Luminosity Optical Transients (ILOTs; red transients; red novae), which are powered by energy release in the core of asymptotic giant branch (AGB) stars are likely to eject the entire envelope, and hence cannot explain ILOTs in AGB and similar stars. There are single-star and binary models for the powering of ILOTs, which are eruptive stars with peak luminosities between those of novae and supernovae. In single-star models, the ejection of gas at velocities of similar to 500-1000 km s(-1) and a possible bright ionizing flash require a shock to propagate from the core outwards. Using a self-similar solution to follow the propagation of the shock through the envelope of two evolved stellar models, a 6 M-circle dot AGB star and an 11 M-circle dot yellow supergiant (YSG) star, we find that the shock that is required to explain the observed mass-loss also ejects most of the envelope. We also show that for the event to have a strong ionizing flash the required energy expels most of the envelope. The removal of most of the envelope is in contradiction with observations. We conclude that single-star models for ILOTs of evolved giant stars encounter severe difficulties.

• 出版日期2014-5