A circumbinary disc in the final stages of common envelope and the core-degenerate scenario for Type Ia supernovae

By A. Kashi, N. Soker. 2011

201 citations recorded by the source corpus.

We study the final stages of the common envelope (CE) evolution and find that a substantial fraction of the ejected mass does not reach the escape velocity. To reach this conclusion we use a self-similar solution under simplifying assumptions. Most of the gravitational energy of a companion white dwarf (WD) is released in the envelope of a massive asymptotic giant branch (AGB) or the red giant branch (RGB) star in a very short time. This rapid energy release forms a blast wave in the envelope. We follow the blast wave propagation from the centre of the AGB outwards, and show that ∼1–10 per cent of the ejected envelope remains bound to the remnant binary system. We suggest that due to angular momentum conservation and further interaction with the binary system, the fall-back material forms a circumbinary disc around the post-AGB Core and the companion WD. The interaction of the circumbinary disc with the binary system will reduce the orbital separation much more than expected of the dynamical phase (where the envelope is ejected) of the CE alone. The smaller orbital separation favours a merger at the end of the CE phase or a short time after, while the core is still hot. This is another channel for the formation of a massive WD with super-Chandrasekhar mass that might explode as a Type Ia supernova. We term this the core-degenerate (CD) scenario.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/2aea180a890b778c33a8f0c21a33e929966f48a0

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Citations in the corpus

AN AMR STUDY OF THE COMMON-ENVELOPE PHASE OF BINARY EVOLUTION (2011, background): “It is possible that ejection of the envelope will be incomplete as some matter may fall back, and the effect of any material surrounding the system in the form of a circumbinary disk (Kashi & Soker 2011) may lead to further orbital decay.”
On the Progenitors of Type Ia Supernovae (2018, unknown): “This scenario has later been picked up and expanded upon by Soker and collaborators (e.g., Kashi & Soker 2011; Ilkov & Soker 2012) to constitute a potential progenitor scenario for SNe Ia in general.”
Observational Clues to the Progenitors of Type Ia Supernovae (2013, background): “Kashi & Soker (2011) have introduced a “core-degenerate” model, in which a WD and the core of an asymptotic-giant-branch (AGB) star merge already in the common-envelope phase.”
Type-Ia Supernova Rates and the Progenitor Problem: A Review (2011, background): “Kashi and Soker (2011) propose a “core-degenerate” model, in which a WD and the core of an AGB star merge already in the commonenvelope phase.”
Common envelope evolution: where we stand and how we can move forward (2012, background): “4.2 Interaction with a post-CE disk If not all of the envelope is ejected then, due to angular momentum conservation and further interaction of the fall-back gas with the binary system, a circumbinary disk may well be formed (Kashi and Soker 2011; De Marco et al. 2011).”
TYPE Ia SUPERNOVA RATE MEASUREMENTS TO REDSHIFT 2.5 FROM CANDELS: SEARCHING FOR PROMPT EXPLOSIONS IN THE EARLY UNIVERSE (2014, background): “More recent variations on these pathways to explosion include the “core degenerate” scenario (Kashi & Soker 2011) and perturbationinduced mergers in triple systems (Thompson 2011).”
The delay-time distribution of Type Ia supernovae from Sloan II (2012, background): “Several ‘SN on hold’ scenarios have also been proposed (Di Stefano, Voss & Claeys 2011; Justham 2011; Kashi & Soker 2011; Ilkov & Soker 2012), where ignition is potentially long delayed.”