Turbulence Generation by Shock-Acoustic-Wave Interaction in Core-Collapse Supernovae

Abstract

Convective instabilities in the advanced stages of nuclear shell burning can play an important role in neutrino-driven supernova explosions. In our previous work, we studied the interaction of vorticity and entropy waves with the supernova shock using a linear perturbations theory. In this paper, we extend our work by studying the effect of acoustic waves. As the acoustic waves cross the shock, the perturbed shock induces a field of entropy and vorticity waves in the post-shock flow. We find that, even when the upstream flow is assumed to be dominated by sonic perturbations, the shock-generated vorticity waves contain most of the turbulent kinetic energy in the post-shock region, while the entropy waves produced behind the shock are responsible for most of the density perturbations. The entropy perturbations are expected to become buoyant as a response to the gravity force and then generate additional turbulence in the post-shock region. This leads to a modest reduction of the critical neutrino luminosity necessary for producing an explosion, which we estimate to be less than ∼ 5%.

Acoustic wave generation in collapsing massive stars with convective shells

“…In addition, the convective eddies have to constantly adjust to new pressure equilibriums, a process that generates strong acoustic waves (e.g., Foglizzo & Tagger 2000). When these perturbations arrive ahead of the supernova shock, their physical properties affect they way they interact with the shock (Abdikamalov et al 2016;Abdikamalov et al 2018;Huete et al 2018;Huete & Abdikamalov 2019;Radice et al 2018).…”

Interaction of two-dimensional spots with a heat releasing/absorbing shock wave: linear interaction approximation results

“…Note that, while ∆Q is here formulated as an independent parameter, a classical assumption for strong detonations (see, e.g. Williams 1985) , the heat absorption typically depends on the shock strength for endothermic processes (which typically ends when saturation is reached), as is the case in ionizing, nuclear dissociating shocks as those occurring in core collapsing supernovae Abdikamalov et al 2018;Huete & Abdikamalov 2019), shock-induced condensation in vapor-liquid two-phase flow (Zhao et al 2008) or cooling induced by radiative loss (Narita 1973).…”

Impact of rotation on the evolution of convective vortices in collapsing stars

“…The convective shell encounters the shock ∼200 ms later (Müller et al 2017). The interaction of the convective vortices with the shock generates perturbations in the postshock flow (Abdikamalov et al 2016;Abdikamalov et al 2018;Huete et al 2018;Huete & Abdikamalov 2019), which amplify the turbulence in that region, pushing the shock forward. Large-scale perturbations were found to have partic-ularly strong impact on the shock expansion (Müller et al 2016;Kazeroni & Abdikamalov 2020).…”