Single-degenerate Type Ia Supernovae Without Hydrogen Contamination
Abstract
The lack of hydrogen in spectra of type Ia supernovae (SNe Ia) is often seen as troublesome for single-degenerate (SD) progenitor models. We argue that, since continued accretion of angular momentum can prevent explosion of the white dwarf, it may be natural for the donor stars in SD progenitors of SNe Ia to exhaust their envelopes and shrink rapidly before the explosion. This outcome seems most likely for SD SN Ia progenitors where mass transfer begins from a giant donor star and might extend to other SD systems. Not only is the amount of hydrogen left in such a system below the current detection limit, but the donor star is typically orders of magnitude smaller than its Roche lobe by the point when an SD SN Ia occurs, in which case attempts to observe collisions between SN shocks and giant donor stars seem unlikely to succeed. We consider the constraints on this model from the circumstellar structures seen in spectra of SN 2006X and suggest a novel explanation for the origin of this material.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 2011
- DOI:
- 10.1088/2041-8205/730/2/L34
- arXiv:
- arXiv:1102.4913
- Bibcode:
- 2011ApJ...730L..34J
- Keywords:
-
- binaries: close;
- supernovae: general;
- white dwarfs;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- Accepted to ApJ Letters on 25 February. This version contains some final improvements suggested by the referee and corrects one daft typo