2003/11/17 by U. Geppert, M. Rheinhardt, J. Gil
Physics and Astronomy · #Astrophysical Phenomena and Observations #Electrical and Electromagnetic Research #Pulsars and Gravitational Waves Research #astro-ph
paper · pdf · doi:10.1051/0004-6361:20034605
published as Astron.Astrophys.412:L33-L36,2003 · 4 pages, 2 figures, accepted by Astronomy & Astrophysics Letters; language improved, 2nd para of Sect. 3 changed
arxiv created 2003/11/17 · openalex publication_date 2003/11/28 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
There is growing evidence, based on both X-ray and radio observations of isolated neutron stars, that besides the large-scale (dipolar) magnetic field, which determines the pulsar spin-down behaviour, small-scale poloidal field components are present, which have surface strengths one to two orders of magnitude larger than the dipolar component. We argue in this paper that the Hall-effect can be an efficient process in producing such small-scale field structures just above the neutron star surface. It is shown that due to a Hall-drift induced instability, poloidal magnetic field structures can be generated from strong subsurface toroidal fields, which are the result of either a dynamo or a thermoelectric instability acting at early times of a neutron star's life. The geometrical structure of these small-scale surface anomalies of the magnetic field resembles that of some types of “star-spots”. The magnetic field strength and the length-scales are comparable with values that can be derived from various observations.