Supplying angular momentum to the jittering jets explosion mechanism using inner convection layers

TL;DR

This paper uses stellar evolution simulations to show that convective angular momentum fluctuations during core collapse can form intermittent accretion disks, potentially powering supernova explosions via the jittering jets mechanism.

Contribution

It demonstrates that inner convective zones during collapse can generate sufficient angular momentum fluctuations to form intermittent accretion disks, supporting the jittering jets explosion model.

Findings

Convective zones develop large angular momentum fluctuations during collapse.

Fluctuations are sufficient to form intermittent accretion disks around neutron stars.

These disks can launch jets, aiding supernova explosions.

Abstract

We conduct one-dimensional stellar evolution simulations in the mass range $13-20 M_{\odot}$ to late core collapse times and find that an inner vigorous convective zone with large specific angular momentum fluctuations appears at the edge of the iron core during the collapse. The compression of this zone during the collapse increases the luminosity there and the convective velocities, such that the specific angular momentum fluctuations are of the order of j_{conv}~5x10^15cm^2/sec. If we consider that three-dimensional simulations show convective velocities that are three to four times larger than what the mixing length theory gives, and that the spiral standing accretion shock instability in the post-shock region of the stalled shock at a radius of ~100km amplify perturbations, we conclude that the fluctuations that develop during core collapse are likely to lead to stochastic (intermittent) accretion disks around the newly born neutron star. In reaching this conclusion we also make two basic assumptions with uncertainties that we discuss. Such intermittent disks can launch jets that explode the star in the frame of the jittering jets explosion mechanism.