Pns dynamo: Theory and observations

We briefly review the turbulent mean-field dynamo action in protoneutron stars that are subject to convective and neutron finger instabilities during the early evolutionary phase. By solving the mean-field induction equation with the simplest model of $��$-quenching we estimate the strength of the generated magnetic field. If the initial period of the protoneutron star is short, then the generated large-scale field is very strong ($> 3 \times 10^{13}$G) and exceeds the small-scale field at the neutron star surface, while if the rotation is moderate, then the pulsars are formed with more or less standard dipole fields ($< 3 \times 10^{13}$G) but with surface small-scale magnetic fields stronger than the dipole field. If rotation is very slow, then the mean-field dynamo does not operate, and the neutron star has no global field.
4 pages, 2 figures, Exotic States of Nuclear Matter. Proceedings of the International Symposium EXOCT07. Held 11-15 June 2007 in Catania University, Italy. Edited by Umberto Lombardo, Marcello Baldo, Fiorella Burgio & Hans-Josef Schulze. Published by World Scientific Publishing