Magnetic Fields in barred galaxies: II Dynamo models

Moss, D. and Shukurov, A. and Sokoloff, D. and Beck, R. and Fletcher, A. (2001) Magnetic Fields in barred galaxies: II Dynamo models. Astronomy & Astrophysics, 380. pp. 55-71. ISSN 0004-6361

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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.

Item Type:	Article
Uncontrolled Keywords:	MAGNETIC FIELDS, MHD, GALAXIES: SPIRAL, GALAXIES: ISM, GALAXIES: MAGNETIC FIELDS, GALAXIES: INDIVIDUAL: NGC 1097
Subjects:	PACS 2010, the AIP's Physics and Astronomy Classification Scheme > 90 GEOPHYSICS, ASTRONOMY, AND ASTROPHYSICS > 98 Stellar systems; interstellar medium; galactic and extragalactic objects and systems; the Universe
Depositing User:	Dr David Moss
Date Deposited:	26 Sep 2006
Last Modified:	20 Oct 2017 14:12
URI:	https://eprints.maths.manchester.ac.uk/id/eprint/610

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