Effects of Rotation and Magnetic Field on the Revival of a Stalled Shock in Supernova Explosions

Kotaro Fujisawa, Hirotada Okawa, Yu Yamamoto, Shoichi Yamada

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

We investigate axisymmetric steady solutions of (magneto)hydrodynamics equations that approximately describe accretion flows through a standing shock wave onto a protoneutron star and discuss the effects of rotation and magnetic field on the revival of the stalled shock wave in supernova explosions. We develop a new powerful numerical method to calculate the two-dimensional steady accretion flows self-consistently. We first confirm the results of preceding papers that there is a critical luminosity of irradiating neutrinos, above which there exists no steady solution in spherical models. If a collapsing star is rotating and/or has a magnetic field, the accretion flows are no longer spherical owing to the centrifugal force and/or Lorentz force, and the critical luminosity is modified. In fact, we find that the critical luminosity is reduced by about 50%-70% for very rapid rotations; the rotation frequencies are 0.2-0.45 s -1 at the radius of r = 1000 km (equivalent to spin periods ∼0.5-0.22 ms at r = 10 km) and about 20%-50% for strong toroidal magnetic fields (the strengths of which are 1.0 × 10 12 -3.0 × 10 12 G at r = 1000 km), depending on the mass accretion rate. These results may also be interpreted as the existence of a critical specific angular momentum or critical magnetic field, above which there exists no steady solution and the standing shock wave will be revived for a given combination of mass accretion rate and neutrino luminosity.

Original languageEnglish
Article number155
JournalAstrophysical Journal
Volume872
Issue number2
DOIs
Publication statusPublished - 2019 Jan 1

Fingerprint

supernovae
explosions
explosion
shock
accretion
magnetic field
shock wave
luminosity
shock waves
magnetic fields
standing wave
neutrinos
stars
centrifugal force
hydrodynamic equations
Lorentz force
angular momentum
numerical method
hydrodynamics
effect

Keywords

  • magnetohydrodynamics (MHD)
  • methods: numerical
  • shock waves
  • stars: magnetic field
  • stars: rotation
  • supernovae: general

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Effects of Rotation and Magnetic Field on the Revival of a Stalled Shock in Supernova Explosions. / Fujisawa, Kotaro; Okawa, Hirotada; Yamamoto, Yu; Yamada, Shoichi.

In: Astrophysical Journal, Vol. 872, No. 2, 155, 01.01.2019.

Research output: Contribution to journalArticle

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