Are there any stable magnetic fields in barotropic stars?
Article first published online: 4 JUN 2012
© 2012 The Authors Monthly Notices of the Royal Astronomical Society © 2012 RAS
Monthly Notices of the Royal Astronomical Society
Volume 424, Issue 1, pages 482–494, July 2012
How to Cite
Lander, S. K. and Jones, D. I. (2012), Are there any stable magnetic fields in barotropic stars?. Monthly Notices of the Royal Astronomical Society, 424: 482–494. doi: 10.1111/j.1365-2966.2012.21213.x
- Issue published online: 5 JUL 2012
- Article first published online: 4 JUN 2012
- Accepted 2012 April 30. Received 2012 April 12; in original form 2012 February 21
- stars: general;
- stars: neutron;
- stars: magnetic field
We construct barotropic stellar equilibria, containing magnetic fields with both poloidal and toroidal field components. We extend earlier results by exploring the effect of different magnetic field and current distributions. Our results suggest that the boundary treatment plays a major role in determining whether the poloidal or toroidal field component is globally dominant. Using time evolutions we provide the first stability test for mixed poloidal–toroidal fields in barotropic stars, finding that all these fields suffer instabilities due to one of the field components: these are localized around the pole for toroidal-dominated equilibria and in the closed-field line region for poloidal-dominated equilibria. Rotation provides only partial stabilization. There appears to be very limited scope for the existence of stable magnetic fields in barotropic stars. We discuss what additional physics from real stars may allow for stable fields.