Bi. Jun et Ml. Norman, MHD SIMULATIONS OF RAYLEIGH-TAYLOR INSTABILITY IN YOUNG SUPERNOVA-REMNANTS, Astrophysics and space science, 233(1-2), 1995, pp. 267-272
Radio observations shows that young supernova remnants such as Tycho a
nd Cas A generally exhibit a circular clumpy shell. This shell shows a
radial magnetic field whose equipartition strength is 2 to 3 orders o
f magnitude higher than the interstellar field. A simple compression o
f the ambient field by the shock can explain neither of these observat
ions. We show that the Rayleigh-Taylor instability which occurs at the
ejecta/ISM interface can explain these observations. We have done MHD
simulations of the instability in the shell of Type-I supernova remna
nts for the first time by utilizing moving grid technique. Our simulat
ion shows that Rayleigh-Taylor and Kelvin-Helmholtz instabilities ampl
ify ambient magnetic fields locally and produce the clumpy radio shell
. Strong magnetic field lines draped around the Rayleigh-Taylor finger
s produce the radial B-vector polarization, whereas thermal bremsstrah
lung from the dense fingers themselves produce the clumpy X-ray emissi
on.