Abstract:
The supernova explosion of massive stars is a complex physical event. Nuclear shell
burning in the nal stages of the lives of massive stars is accompanied by strong turbulent
convection. The resulting
uctuations aid supernova explosion by amplifying the
non-radial
ow in the post-shock region. We investigate the physical mechanism behind
this ampli cation using a linear perturbation theory. We model the shock wave
as a one-dimensional planar discontinuity and consider its interaction with vorticity
and entropy perturbations in the upstream
ow. We nd that, as the perturbations
cross the shock, their total turbulent kinetic energy is ampli ed by a factor of 2,
while the average linear size of turbulent eddies decreases by about the same factor.
We also study the e ects of the interaction of acoustic perturbations with the shock
wave. We determine that the post-shock turbulent kinetic energy is dominated by
vorticity waves. In addition, we nd that the kinetic energy ampli cation of perturbations
increases as / M21
. Finally, we discuss the implication of our results for
the supernova explosion mechanism. We show that the upstream perturbations can
decrease the critical neutrino luminosity for producing explosion by several percent.