7th Asia-Pacific Conference on Plasma Physics, 12-17 Nov, 2023 at Port Messe Nagoya

Dependence of the magnetic field and rotation on the explosion mechanism ofcore-collapse supernovae
J. Matsumoto1, T. Takiwaki2, K. Kotake3, Y. Asahina4 and H. R. Takahashi51Keio Institute of Pure and Applied Sciences, Keio University,
2
National Astronomical Observatory of Japan,
3
Department of Applied Physics, Fukuoka University,
4
Center for Computational Sciences, Tsukuba University,
5
Department of Natural Sciences, Faculty of Arts and Sciences, Komazawa University
e-mail (speaker): jin@rk.phys.keio.ac.jpMassive stars undergo explosive phenomena during theterminal stage of their lives. These explosions are called
core-collapse supernovae (CCSNe) and manifest as
exceptionally energetic and luminous occurrences in theUniverse. An outwardly propagating shock wave isexcited after the bounce of the core due to thegravitational collapse of the massive star. The explosion
occurs when this shock wave reaches the surface of themassive star. However, its advancement is arrested
within the Fe core because of the ram pressure exerted
on the shock surface within the upstream region.
Although the neutrino-heating mechanism is considered
to be a key process in driving the explosion of massive
stars, the CCSN explosion mechanism is not completely
understood yet. Within this framework, neutrinos emitted
by a protoneutron star, generated at the epicenter of thecollapsing massive star, serve to thermally energize thematter behind the stalled shock wave. The turbulencebehind the shock, resulting from convection arising due
to negative entropy gradients and/or hydrodynamic
instabilities, profoundly amplifies the efficacy ofneutrino heating. This is because if the turbulence fully
develops, the matter is effectively exposed by neutrinos
and can gain substantial thermal energy to overcome theram pressure due to the mass accretion.

The impact of the magnetic field on the explosion
mechanism of CCSNe is a long-standing mystery.
Recently,
wehaveupdated
ourneutrino-radiation-hydrodynamics
supernovacode(3DnSNe)[1] to include magnetohydrodynamics (MHD)[2].
Using this code, we have performed three-dimensional(3D) MHD simulations for the evolution of non- andslowly-rotating stellar cores[3,4]. Figure 1 shows 3D
configuration of magnetic field lines and shock surface
before/after the onset of the development of theturbulence for a slowly-rotating model. We find that theneutrino heating is the main driver for the explosion in
our non-rotating model, whereas the drastic
amplification of the magnetic field in a turbulent flow isresponsible for the explosion in our rotating models.
This work was supported by JSPS KAKENHI Grant
Number JP22H01223.
References[1] T. Takiwaki et al., MNRAS, 2016, 461, L112
[2] J. Matsumoto et al., MNRAS, 2020, 499, 4174
[3] J. Matsumoto et al., MNRAS, 2022, 516, 1752
[4] J. Matsumoto et al., submitted to MNRAS Letters,2023

Figure 1. Snapshots of 3D configuration of magnetic field lines and the shock surface (whitish sphere) for a
slowly-rotating model. The colors of magnetic field lines mean the absolute strength of the magnetic field.
Panel (a) and (b) corresponds to the time tpb=100 and 150 ms after bounce, respectively.