Alfven Wave-Driven Supernova Explosion

TL;DR

This paper explores how Alfven waves generated inside proto-neutron stars can revive stalled supernova shocks by heating matter, with simulations showing shock revival depends on magnetic field strength and wave amplitude.

Contribution

It introduces a new mechanism for supernova shock revival driven by Alfven waves, supported by 1D hydrodynamical simulations quantifying the conditions needed.

Findings

Shock revival occurs if surface magnetic field > 2e15 G.

Wave amplitude > 20% of local sound speed is necessary.

Explosion energy is self-regulating and insensitive to initial conditions.

Abstract

We investigate the role of Alfven waves in the core-collapse supernova (SN) explosion. We assume that Alfven waves are generated by convections inside a proto-neutron star (PNS) and emitted from its surface. Then these waves propagate outwards, dissipate via nonlinear processes, and heat up matter around a stalled prompt shock. To quantitatively assess the importance of this process for the revival of the stalled shock, we perform 1D time-dependent hydrodynamical simulations, taking into account the heating via the dissipation of Alfven waves that propagate radially outwards along open flux tubes. We show that the shock revival occurs if the surface field strength is larger than ~2e15 G and if the amplitude of velocity fluctuation at the PNS surface is larger than 20% of the local sound speed. Interestingly, the Alfven wave mechanism is self-regulating in the sense that the explosion energy is not very sensitive to the surface field strength and initial amplitude of Alfven waves as long as they are larger than the threshold values given above.