Physics of Massive Stars: Simulations of Intermediate Luminosity Optical Transients

TYPEAstrophysics Seminar
Speaker:Amir Michaelis
Affiliation:Ariel University
Date:06.07.2022
Time:14:30 - 15:30
Location:Lidow 620
Abstract:

Intermediate Luminosity Optical Transients (ILOTs) are a group of stellar outbursts in the energy gap between novae and supernovae. As their name suggests, they emit light mostly in the optical spectrum, and in some cases they can be confused with real supernovae. Luminous Red Novae (LRN) are a subgroup of ILOTs that are suspected to be stars that erupt as a result of a merger event (“merger-burst”). In this event, two stars, the primary and the less dense secondary are merged. The denser star will destroy the less dense star in a merger process. V838 Mon is a well known object in this class and its 2002 outburst is considered as a LRN prototype. It was modeled as a merger of 8 solar mass main sequence star with a 0.3-1 solar mass secondary young stellar object. In this study we assume that the late stage of a merger results in a thick accretion belt of shredded matter. We simulate this belt as a Keplerian thick accretion disk surrounding the primary. This disk is unstable and undergoes collapse and depletion. We investigate the details of such a process and compare it to common ILOTs observations. We find that for the first ~60 days the accretion rate, light curve and temperature of such a process are in good agreement with observations of V838 Mon and other ILOTs. We suggest that this model can be used to gain insights into the late stages of LRN and other ILOTs