Spruit 2007 Review on the origin of NS magnetic fields

主要内容:
Three popular scenarios: 1. fossil magnetic field (almost excluded); 2. generated internally in the protostars; 3. generated in the collapsing.

精彩摘抄:


文章信息:

arXiv:0711.3650 [pdf, other]

Title: Origin of neutron star magnetic fields

Authors: H.C. Spruit

Comments: Review to appear in "40 years of pulsars", ed. A. Cumming, AIP

Subjects: Astrophysics (astro-ph)

Possible origins of the magnetic fields of neutron stars include inheritance from the main sequence progenitor and dynamo action at some stage of evolution of progenitor. Inheritance is not sufficient to explain the fields of magnetars. Energetic considerations point to differential rotation in the final stages of core collapse process as the most likely source of field generation, at least for magnetars. A runaway phase of exponential growth is needed to achieve sufficient field amplification during relevant phase of core collapse; it can probably be provided by a some form of magnetorotational instability. Once formed in core collapse, the field is in danger of decaying again by magnetic instabilities. The evolution of a magnetic field in a newly formed neutron star is discussed, with emphasis on the existence of stable equilibrium configurations as end products of this evolution, and the role of magnetic helicity in their existence.