EDP Sciences
Free access
Volume 393, Number 2, October II 2002
Page(s) 685 - 691
Section Physical and chemical processes
DOI http://dx.doi.org/10.1051/0004-6361:20021026

A&A 393, 685-691 (2002)
DOI: 10.1051/0004-6361:20021026

Generation of magnetic seed fields in self-gravitating protogalactic clouds

G. T. Birk1, 2, H. Wiechen2, 3 and H. Lesch1, 2

1  Institute for Astronomy and Astrophysics, University of Munich, Germany
2  Centre of Interdisciplinary Plasma Science, Garching, Germany
3  Max-Planck-Institut für extraterrestrische Physik, Garching, Germany

(Received 14 March 2002 / Accepted 11 July 2002 )

The seed magnetization of protogalaxies can be provided by relative shear flows and collisional friction of the ionized and the neutral fluid components in partially ionized self-gravitating and rotating protogalactic clouds. The gravitational potential of a collapsing protogalactic cloud is the ultimate energy source that partly is converted to magnetic fields and the associated electric currents by collisional momentum transfer in the partially ionized systems. Self-consistent plasma-neutral gas simulations, that take into account self-gravitation, show that magnetic fields of the order of some 10-14 G are generated on spatial scales of some 100 pc in about $7 \times 10^6$ years.

Key words: magnetic fields -- galaxies: formation -- methods: numerical

Offprint request: G. T. Birk, birk@usm.uni-muenchen.de

© ESO 2002