Type Ia Supernova Remnants: Shaping by Iron Bullets

TL;DR

This study uses 2D hydrodynamical simulations to suggest that dense iron clumps in type Ia supernova remnants can create protrusions, providing clues about the explosion mechanism and progenitor rotation.

Contribution

It introduces a simulation-based explanation for protrusions in SNR Ia caused by iron bullets, linking them to explosion models and progenitor rotation.

Findings

Iron clumps can form protrusions in SNR Ia.

Protrusions may indicate a preferred axis from progenitor rotation.

Simulation results match observed features in some SNR Ia.

Abstract

Using 2D numerical hydrodynamical simulations of type Ia supernova remnants (SNR Ia) we show that iron clumps few times denser than the rest of the SN ejecta might form protrusions in an otherwise spherical SNR. Such protrusions exist in some SNR Ia, e.g., SNR 1885 and Tycho. Iron clumps are expected to form in the deflagration to detonation explosion model. In SNR Ia where there are two opposite protrusions, termed ears, such as Kepler's SNR and SNR G1.9+0.3, our scenario implies that the dense clumps, or iron bullets, were formed along an axis. Such a preferred axis can result from a rotating white dwarf progenitor. If our claim holds, this offers an important clue to the SN Ia explosion scenario.