A&A 457, 209-222 (2006)
Axisymmetric simulations of magnetorotational core collapse: approximate inclusion of general relativistic effectsM. Obergaulinger1, M. A. Aloy1, 2, H. Dimmelmeier1 and E. Müller1
1 Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching, Germany
2 Departamento de Astronomía y Astrofísica, Universidad de Valencia, 46100 Burjassot, Spain
(Received 7 February 2006 / Accepted 1 May 2006)
We continue our investigations of the magnetorotational collapse of stellar cores by discussing simulations performed with a modified Newtonian gravitational potential that mimics general relativistic effects. The approximate TOV gravitational potential used in our simulations captures several basic features of fully relativistic simulations quite well. In particular, it is able to correctly reproduce the behavior of models that show a qualitative change both of the dynamics and the gravitational wave signal when switching from Newtonian to fully relativistic simulations. For models where the dynamics and gravitational wave signals are already captured qualitatively correctly by a Newtonian potential, the results of the Newtonian and the approximate TOV models differ quantitatively. The collapse proceeds to higher densities with the approximate TOV potential, allowing for a more efficient amplification of the magnetic field by differential rotation. The strength of the saturation fields ( at the surface of the inner core) is a factor of two to three higher than in Newtonian gravity.
Key words: magnetohydrodynamics (MHD) -- gravitational waves -- stars: magnetic fields -- supernovae: general
© ESO 2006