Session 74 - Supernova Remnants.
Display session, Thursday, June 13
Great Hall,

## [74.10] A New Model for Protrusions from a Supernova Shell

B. Jun, T. W. Jones (U.Minnesota), M. L. Norman (U.Illinois)

A new mechanism is proposed for protrusions from a supernova shell observed in SN 1986J. Our numerical simulation demonstrates that protrusions can be generated by large Rayleigh-Taylor fingers developed near the contact discontinuity as the supernova remnant expands into a clumpy (cloudy) circumstellar medium. The Rayleigh-Taylor fingers obtain a sufficient terminal velocity to penetrate the forward shock by taking extra kinetic energy from vortices generated by shock-cloud interactions. Ambient magnetic fields are stretched and amplified as the Rayleigh-Taylor fingers protrude, which indicate the possible site of strong radio emission. The material in the protrusions originates from the ejected stellar material with greatly enhanced heavy elements, therefore it can be a strong X-ray emitter. The timescale for the protrusions to form depends on the size and mass density of clouds being engulfed by the supernova shock. Our model suggests that the circumstellar medium of SN 1986J includes a number of small clumps (roughly r \sim 1.5 \times 10^15cm) originating possibly from presupernova winds.