Core-collapse supernovae are thermonuclear explosions

Speaker: 
Dr. Doron Kushnir (Weizmann Institute of Science)
Date: 
Thursday, August 2, 2018 - 1:00pm
There is strong evidence that core-collapse supernovae (CCSNe) are explosions of massive stars, initiated by the gravitational collapse of the stars' iron core. It is widely thought that the explosion is obtained due to the deposition in the envelope of a small fraction (~1%) of the gravitational energy (~1e53 erg) released in neutrinos from the core, leading to the ~1e51 observed kinetic energy of the ejected material. However, so far this neutrino-mechanism model has not been satisfactorily demonstrated. Burbidge et al. (1957) suggested a different mechanism, in which the adiabatic heating of the outer stellar shells as they collapse triggers a thermonuclear explosion. This collapse-induced thermonuclear explosion (CITE) has the advantage of naturally producing ~1e51 erg from the thermonuclear burning of a solar mass of light elements, with a gain of ~MeV per nucleon. Early studies suggested that this mechanism fails, and the idea was subsequently abandoned. 
  I will demonstrate that CITE is possible for some initial profiles, and the resulting explosions have kinetic energies and ejected Ni56 masses which cover the observed ranges of CCSNe (including types II and stripped-envelope supernovae). In particular, simulations for massive progenitors, which are similar to Wolf-Rayet stars, predict high kinetic energy, high ejected Ni56 mass and small ejecta mass, in a general agreement with the observed properties of striped-envelope supernovae. Moreover, the in-falling mass in this case is large (~20 solar masses), providing a natural explanation for the massive black holes observed by LIGO. 
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