Imprints of Stellar Mergers on Core Collapse Supernovae and their Progenitors

Imprints of stellar mergers on core collapse supernovae and their progenitors" 
Abstract: Supernova SN 1987A is often considered the poster child of core-collapse supernova, whose blue supergiant progenitor was born from a stellar merger. Recent studies also showed that other peculiar Type II SNe like 87A, may also have been explosions of massive blue supergiants born from stellar mergers. While these studies were specifically geared for 87A-like SNe, the vast parameter space of binary systems that experience post-main sequence mergers is still to be investigated. Using MESA, we evolve stellar models across a range of initial binary parameters through the merger phase, until near Fe core-collapse. For this we build a 1D merger scheme based on 3D hydrodynamic simulations, which mimics the mixing of the secondary main-sequence star in the common envelope. Such post-merger stars may also leave tell-tale signatures in the surface abundance patterns and HR diagram positions in observed stellar populations. The final structure of the star before explosion will also be radically different from other hydrogen-rich SNe progenitors. In this talk, I will present the first results of this exploratory study on massive binary-merger progenitors and their SNe.