Shock–turbulence interaction in core-collapse supernovae

Abstract

Nuclear shell burning in the final stages of the lives of massive stars is accompanied by strong turbulent convection. The resulting fluctuations aid supernova explosion by amplifying the non-radial flow in the post-shock region. In this work, we investigate the physical mechanism behind this amplification using a linear perturbation theory. We model the shock wave as a one-dimensional planar discontinuity and consider its interaction with vorticity and entropy perturbations in the upstream flow. We find that, as the perturbations cross the shock, their total turbulent kinetic energy is amplified by a factor of ∼ 2, while the average linear size of turbulent eddies decreases by about the same factor. These values are not sensitive to the parameters of the upstream turbulence and the nuclear dissociation efficiency at the shock. Finally, we discuss the implication of our results for the supernova explosion mechanism. We show that the upstream perturbations can decrease the critical neutrino luminosity for producing explosion by several percent.

Crucial Physical Dependencies of the Core-Collapse Supernova Mechanism

“…However, when spherical progenitor models do not readily lead to explosion, the initial perturbation spectrum in the progenitor's convective silicon and oxygen zones could certainly affect the timescales for the generation of turbulence behind the stalled shock and be a factor in the onset of explosion (Couch and Ott 2013;Müller and Janka 2015;Abdikamalov et al 2016;Müller et al 2017). Specifically, the magnitude, character, and spectra of seed perturbations will affect how quickly turbulence reaches the non-linear regime and, perhaps, whether turbulence grows to non-linearity at all during the finite time the accreta are in the unstable gain region.…”

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).…”

Gravitational Waves from the Phase Transition of NS to QS

“…Some amount of energy will be released in the form of neutrino emission. However, a significant amount of it can go into emitting gravitational waves [25,26].…”

“…Also, there will be other dissipation mechanisms, hence in this approach the energy budget available to gravitational waves is uncertain. In other approach implemented by Lin et al [25] and Admikamalov et al [26], it is considered that quark matter content when appears inside an NS, due to quark matter EoS having less pressure than nuclear matter the star undergoes a micro-collapse. This results in quadrupole moment change, and the gravitational wave is generated.…”