On Type Ia Supernovae From The Collisions of Two White Dwarfs

TL;DR

This paper investigates white dwarf collisions as a possible origin for Type Ia Supernovae, using simulations to show such events can produce enough Ni56 to resemble underluminous supernovae or new transient classes.

Contribution

It presents the first detailed simulations of white dwarf collisions at various impact parameters, linking these events to potential underluminous SNIa or novel transients.

Findings

Collisions produce about 0.4 solar masses of Ni56.

White dwarf collisions could explain some underluminous SNIa.

Potential detection rates in globular clusters are estimated.

Abstract

We explore collisions between two white dwarfs as a pathway for making Type Ia Supernovae (SNIa). White dwarf number densities in globular clusters allow 10-100 redshift <1 collisions per year, and observations by (Chomiuk et al. 2008) of globular clusters in the nearby S0 galaxy NGC 7457 have detected what is likely to be a SNIa remnant. We carry out simulations of the collision between two 0.6 solar mass white dwarfs at various impact parameters and mass resolutions. For impact parameters less than half the radius of the white dwarf, we find such collisions produce approximately 0.4 solar masses of Ni56, making such events potential candidates for underluminous SNIa or a new class of transients between Novae and SNIa.