Shock Corrugation by Rayleigh-Taylor Instability in GRB Afterglow Jets

Understand

Afterglow jets are Rayleigh-Taylor unstable and therefore turbulent during the early part of their deceleration.

• There are also several processes which actively cool the jet.
• In this letter, we demonstrate that if cooling significantly increases the compressibility of the flow, the turbulence collides with the forward shock, destabilizing and corrugating it.
• In this case, the forward shock is turbulent enough to produce the magnetic fields responsible for synchrotron emission via small scale turbulent dynamo.