The explosion of supernova 2011fe in the frame of the core-degenerate scenario

TL;DR

This paper proposes that the core-degenerate scenario, involving a white dwarf merging with an AGB star's core and spinning down over billions of years, best explains the properties of supernova SN 2011fe, including its composition and explosion characteristics.

Contribution

It introduces the core-degenerate scenario as a viable explanation for SN 2011fe's properties, emphasizing long delay times and specific ejecta composition.

Findings

Core-degenerate scenario explains SN 2011fe's properties.

Long delay times allow for carbon-enriched outer layers.

Matches observed ejecta composition and explosion features.

Abstract

We argue that the properties of the Type Ia supernova (SN Ia) SN 2011fe can be best explained within the frame of the core-degenerate (CD) scenario. In the CD scenario a white dwarf (WD) merges with the core of an asymptotic giant branch (AGB) star and forms a rapidly rotating WD, with a mass close to and above the critical mass for explosion. Rapid rotation prevents immediate collapse and/or explosion. Spinning down over a time of 0-10 Gyr brings the WD to explosion. A very long delayed explosion to post-crystallization phase, which lasts for about 2 Gyr leads to the formation of a highly carbon-enriched outer layer. This can account for the carbon-rich composition of the fastest-moving ejecta of SN 2011fe. In reaching the conclusion that the CD scenario best explains the observed properties of SN 2011fe we consider both its specific properties, like a very compact exploding object and carbon rich composition of the fastest-moving ejecta, and the general properties of SNe Ia.