A Spallation Model for the Titanium-rich Supernova Remnant Cassiopeia A
  Titanium-rich subluminous supernovae are rare and challenge current SN nucleosynthesis models. We present a model in which ejecta from a standard Supernova is impacted by a second explosion of the neutron star (a Quark-nova), resulting in spallation reactions that lead to 56Ni destruction and 44Ti creation under the right conditions. Basic calculations of the spallation products shows that a delay between the two explosions of ~ 5 days reproduces the observed abundance of 44Ti in Cas A and explains its low luminosity as a result of the destruction of 56Ni. Our results could have important implications for lightcurves of subluminous as well as superluminous supernovae. 
Rachid Ouyed (1), Denis Leahy (1), Amir Ouyed (1), Prashanth Jaikumar   (2) ((1) Physics&Astronomy, University of Calgary, A...
astro-ph.HE nucl-th