On non-axisymmetric magnetic equilibria in stars

被引:103
作者
Braithwaite, Jonathan [1 ]
机构
[1] Canadian Inst Theoret Astrophys, Toronto, ON M5S 3H8, Canada
关键词
MHD; stars : chemically peculiar; stars : magnetic fields; stars : neutron; white dwarfs;
D O I
10.1111/j.1365-2966.2008.13218.x
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
In previous work, stable approximately axisymmetric equilibrium configurations for magnetic stars were found by numerical simulation. Here, I investigate the conditions under which more complex, non-axisymmetric configurations can form. I present numerical simulations of the formation of stable equilibria from turbulent initial conditions and demonstrate the existence of non-axisymmetric equilibria consisting of twisted flux tubes lying horizontally below the surface of the star, meandering around the star in random patterns. Whether such a non-axisymmetric equilibrium or a simple axisymmetric equilibrium forms depends on the radial profile of the strength of the initial magnetic field. The results could explain observations of non-dipolar fields on stars such as the B0.2 main-sequence star tau Sco or the pulsar 1E 1207.4-5209. The secular evolution of these equilibria due to Ohmic and buoyancy processes is also examined.
引用
收藏
页码:1947 / 1958
页数:12
相关论文
共 38 条
[1]   Precession of the isolated neutron star PSR B1828-11 [J].
Akgün, T ;
Link, B ;
Wasserman, I .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2006, 365 (02) :653-672
[2]   Weak magnetic fields in Ap/Bp stars - Evidence for a dipole field lower limit and a tentative interpretation of the magnetic dichotomy [J].
Auriere, M. ;
Wade, G. A. ;
Silvester, J. ;
Lignieres, F. ;
Bagnulo, S. ;
Bale, K. ;
Dintrans, B. ;
Donati, J. F. ;
Folsom, C. P. ;
Gruberbauer, M. ;
Hoa, A. Hui Bon ;
Jeffers, S. ;
Johnson, N. ;
Landstreet, J. D. ;
Lebre, A. ;
Lueftinger, T. ;
Marsden, S. ;
Mouillet, D. ;
Naseri, S. ;
Paletou, F. ;
Petit, P. ;
Power, J. ;
Rincon, F. ;
Strasser, S. ;
Toque, N. .
ASTRONOMY & ASTROPHYSICS, 2007, 475 (03) :1053-U111
[3]   ZEEMAN EFFECT IN STELLAR SPECTRA [J].
BABCOCK, HW .
ASTROPHYSICAL JOURNAL, 1947, 105 (01) :105-119
[4]   Chandra X-ray observatory observations of the globular cluster M28 and its millisecond pulsar PSR B1821-24 [J].
Becker, W ;
Swartz, DA ;
Pavlov, GG ;
Elsner, RF ;
Grindlay, J ;
Mignani, R ;
Tennant, AF ;
Backer, D ;
Pulone, L ;
Testa, V ;
Weisskopf, MC .
ASTROPHYSICAL JOURNAL, 2003, 594 (02) :798-811
[5]   AN ENERGY PRINCIPLE FOR HYDROMAGNETIC STABILITY PROBLEMS [J].
BERNSTEIN, IB ;
FRIEMAN, EA ;
KRUSKAL, MD ;
KULSRUD, RM .
PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL AND PHYSICAL SCIENCES, 1958, 244 (1236) :17-40
[6]  
Beuermann K, 2007, ASTRON ASTROPHYS, V463, P647, DOI 10.1051/0004-6361:20066332
[7]   Protoneutron star dynamos: pulsars, magnetars, and radio-silent X-ray emitting neutron stars [J].
Bonanno, A ;
Urpin, V ;
Belvedere, G .
ASTRONOMY & ASTROPHYSICS, 2006, 451 (03) :1049-1052
[8]   The stability of poloidal magnetic fields in rotating stars [J].
Braithwaite, J. .
ASTRONOMY & ASTROPHYSICS, 2007, 469 (01) :275-284
[9]   Stable magnetic fields in stellar interiors [J].
Braithwaite, J ;
Nordlund, Å .
ASTRONOMY & ASTROPHYSICS, 2006, 450 (03) :1077-1095
[10]   Evolution of the magnetic field in magnetars [J].
Braithwaite, J ;
Spruit, HC .
ASTRONOMY & ASTROPHYSICS, 2006, 450 (03) :1097-1106