A Spallation Model for the Titanium-rich Supernova Remnant Cassiopeia A

TL;DR

This paper proposes a model where a second explosion impacts supernova ejecta, causing spallation reactions that explain the observed titanium-44 abundance and low luminosity in the Cassiopeia A supernova remnant.

Contribution

It introduces a novel spallation model involving a quark-nova impacting supernova ejecta to explain titanium-rich supernova remnants.

Findings

A delay of about 5 days between explosions reproduces observed 44Ti levels.

The model explains low luminosity through destruction of 56Ni.

Implications for lightcurves of various supernova types.

Abstract

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.