Spiral instability can drive thermonuclear explosions in binary white dwarf mergers
Astrophysical Journal Letters
American Astronomical Society
© 2015. The American Astronomical Society. All rights reserved.
Thermonuclear, or Type Ia supernovae (SNe Ia), originate from the explosion of carbon–oxygen white dwarfs, and serve as standardizable cosmological candles. However, despite their importance, the nature of the progenitor systems that give rise to SNe Ia has not been hitherto elucidated. Observational evidence favors the double-degenerate channel in which merging white dwarf binaries lead to SNe Ia. Furthermore, significant discrepancies exist between observations and theory, and to date, there has been no self-consistent merger model that yields a SNe Ia. Here we show that a spiral mode instability in the accretion disk formed during a binary white dwarf merger leads to a detonation on a dynamical timescale. This mechanism sheds light on how white dwarf mergers may frequently yield SNe Ia.
We thank James Guillochon, Lars Bildsten, Matthew Wise, and Gunnar Martin Lellep for useful discussions and Matthias Aegenheyster for his contributions to the FLASH analysis codes. E.G.B. acknowledges support from MCINN grant AYA2011–23102, and from the European Union FEDER fund. The software used in this work was in part developed by the DOE NNSA-ASC OASCR Flash Center at the University of Chicago. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number ACI-1053575. Simulations at UMass Dartmouth were performed on a computer cluster supported by NSF grant CNS-0959382 and AFOSR DURIP grant FA9550-10-1-0354. This research has made use of NASA's Astrophysics Data System and the yt astrophysics analysis software suite Turk et al. (2011). R.T.F. is grateful to have had the opportunity to complete this paper during a visit to the Kavli Institute for Theoretical Physics, which is supported in part by the National Science Foundation under grant No. NSF PHY11-25915.
This is the final version of the article. Available from American Astronomical Society via the DOI in this record.
Vol. 800, No. 1, L7