Magnetic fields and radio polarization of barred galaxies |
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| Authors: | Katarzyna Otmianowska-Mazur Detlef Elstner |
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| Institution: | (1) Astronomical Observatory Jagiellonian University, Kraków, Poland;(2) Astrophysikalishes Institut Potsdam, Germany |
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| Abstract: | In order to simulate evolution of a large-scale magnetic field in a barred galaxy possessing a gaseous halo we apply a three-dimensional
(3D) MHD numerical model. We solve a induction equation using a time-dependent velocity field of molecular gas resulting from
self-consistent 3D N-body simulations of a galactic disk. The gaseous halo rotates differentially co-rotating with the disk.
In our model we introduce the dynamo process causing the amplification of the magnetic field as well as the formation of field
structures high above the galactic disk. The simulated magnetic fields are used to construct the models of a high-frequency
(Faraday rotation-free) polarized radio emission that accounts for effects of projection and limited resolution, and is thus
suitable for direct comparison with observations. We found that the resultant magnetic field correctly reproduces the observed
structures of polarization B-vectors, forming coherent patterns well aligned with spiral arms and with the bar. The process
initializing a wave-like behavior of the magnetic field, which efficiently forms magnetic maxima between the spiral arms,
is demonstrated.
This revised version was published online in August 2006 with corrections to the Cover Date. |
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| Keywords: | Simulations: MHD N-body Galaxies: magnetic fields bars |
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