A&A 380, 55-71 (2001)
DOI: 10.1051/0004-6361:20011343
Magnetic fields in barred galaxies
II. Dynamo models
D. Moss1, A. Shukurov2, D. Sokoloff3, R. Beck4 and A. Fletcher21 Department of Mathematics, University of Manchester, Manchester M13 9PL, UK
2 Department of Mathematics, University of Newcastle, Newcastle on Tyne NE1 7RU, UK
3 Department of Physics, Moscow State University, Moscow 19899, Russia
4 Max Planck Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
(Received 5 July 2001 / Accepted 24 September 2001 )
Abstract
We study the generation and maintenance of large-scale magnetic
fields in barred galaxies. We take a velocity field (with strong
noncircular components) from a published gas dynamical simulation
of Athanassoula (1992), and use this as input to a galactic dynamo
calculation. Our work is largely motivated by recent high quality
VLA radio observations of the barred galaxy NGC 1097, and we
compare our results in detail with the regular magnetic fields
deduced from these observations. We are able to reproduce most of
the conspicuous large-scale features of the observed regular field,
including
the field structure in the central regions, by using a simple
mean-field dynamo model in which the intensity of interstellar
turbulence (more precisely, the turbulent diffusivity) is enhanced
by a factor of 2-6 in the dust lanes and near the circumnuclear
ring. We argue that magnetic fields can be dynamically important,
and therefore should be included in models of gas flow in barred
galaxies.
Key words: magnetic fields -- MHD -- galaxies: spiral -- galaxies: ISM -- galaxies: magnetic fields -- galaxies: individual: NGC 1097
Offprint request: D. Moss, anvar.shukurov@newcastle.ac.uk
SIMBAD Objects
© ESO 2001

BibSonomy
CiteUlike
Del.icio.us
Digg
Facebook
Mendeley
Twitter