EDP Sciences
Free access
Volume 420, Number 2, June III 2004
Page(s) 411 - 422
Section Astrophysical processes
DOI http://dx.doi.org/10.1051/0004-6361:20035721

A&A 420, 411-422 (2004)
DOI: 10.1051/0004-6361:20035721

The cellular burning regime in type Ia supernova explosions

I. Flame propagation into quiescent fuel
F. K. Röpke1, W. Hillebrandt1 and J. C. Niemeyer2

1  Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching, Germany
    e-mail: fritz@mpa-garching.mpg.de; wfh@mpa-garching.mpg.de
2  Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
    e-mail: niemeyer@astro.uni-wuerzburg.de

(Received 21 November 2003 / Accepted 4 March 2004 )

We present a numerical investigation of the cellular burning regime in Type Ia supernova explosions. This regime holds at small scales (i.e. below the Gibson scale), which are unresolved in large-scale Type Ia supernova simulations. The fundamental effects that dominate the flame evolution here are the Landau-Darrieus instability and its nonlinear stabilization, leading to a stabilization of the flame in a cellular shape. The flame propagation into quiescent fuel is investigated addressing the dependence of the simulation results on the specific parameters of the numerical setup. Furthermore, we investigate the flame stability at a range of fuel densities. This is directly connected to the questions of active turbulent combustion (a mechanism of flame destabilization and subsequent self-turbulization) and a deflagration-to-detonation transition of the flame. In our simulations we find no substantial destabilization of the flame when propagating into quiescent fuels of densities down to $\sim $ $10^7 \,{\rm g} \,{\rm cm}^{-3}$, corroborating fundamental assumptions of large-scale SN Ia explosion models. For these models, however, we suggest an increased lower cutoff for the flame propagation velocity to take the cellular burning regime into account.

Key words: stars: supernovae: general -- hydrodynamics -- instabilities

Offprint request: F. K. Röpke, fritz@mpa-garching.mpg.de

© ESO 2004