Open AccessEmergence of magnetic field due to spin‐polarized baryon matter in neutron stars
Author(s) -
Kutschera M.
Publication year - 1999
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1999.02655.x
Subject(s) - physics , neutron star , ferromagnetism , condensed matter physics , magnetic field , astrophysics , pulsar , field (mathematics) , saturation (graph theory) , millisecond pulsar , quantum mechanics , mathematics , combinatorics , pure mathematics
A model of the ferromagnetic origin of magnetic fields of neutron stars is considered. In this model, the magnetic phase transition occurs inside the core of neutron stars soon after formation. However, owing to the high electrical conductivity the core magnetic field is initially fully screened. We study how this magnetic field emerges for an outside observer. After some time, the induced field that screens the ferromagnetic field decays enough to uncover a detectable fraction of the ferromagnetic field. We calculate the time‐scale of decay of the screening field and study how it depends on the size of the ferromagnetic core. We find that the same fractional decay of the screening field occurs earlier for larger cores. We conjecture that weak fields of millisecond pulsars, B ∼10 8 –10 9 G, could be identified with ferromagnetic fields of unshielded fraction ε ∼10 −4 –10 −3 resulting from the decay of screening fields by a factor 1− ε in ∼10 8 yr since their birth.