Katarzyna Otmianowska-Mazur (OA UJ Kraków)Grzegorz Kowal (Uniw. Sao Paulo, Brazylia/OA UJ Kraków)
Katarzyna Kulpa-Dybeł (OA UJ Kraków)Hubert Siejkowski, (OA UJ Kraków)
Marian Soida (OA UJ Kraków)Barbara Kulesza-Żydzik (OA UJ Kraków)
Michał Hanasz (CA UMK, Toruń)Dominik Woltański (CA UMK, Toruń)Dominik Bomans (RUHR, Bochum)
3D numerical simulations of magnetic 3D numerical simulations of magnetic field evolution in barred galaxies and in field evolution in barred galaxies and in spiral galaxies under influence of tidal spiral galaxies under influence of tidal
forcesforces
Schedule of my talk:
Introduction: observations and simulation
Magnetic field evolution in barred galaxies
Magnetic field evolution in galaxies under influence of tidal forces
Observations of magnetic field in barred and spiral galaxies
Most of spiral and barred galaxies have large-scale ordered magnetic field structures
The existence of bars, spirals and rings considerably influences large-scale magnetic field configuration
In most of barred galaxies we observe strong interactions between gas and large-scale magnetic field which undergo shear and compression
Similar facts are observed in spiral galaxies under influence of tidal forces
Ref.Beck et al.. 2002, A&A 391, 83 Patrikeev, I.; Fletcher, A.et al. 2006 A&A 458, 441
Simulations
Moss et al. 2007,A&A 465, 157
Magnetic fields in barred galaxies. Modelling of NGC 1365
Computation 3D, dynamo, velocity fitted to HI and CO
Agreement of the model and observation is good in top left and bottom right regions near the bar, differences are much higher in other regions.
Kotarba et al. 2009, MNRAS 397, 733
Magnetic field structure due to the global velocity field in spiral galaxies
Self-consistent N-body/SPH simulation with solution of induction equation in SPH parts
The Authors obtained magnetic field structures similar to observed in spiral galaxies
Results of our 3D simulations
Kulesza-Żydzik, Kulpa-Dybeł, Otmianowska-Mazur, Kowal, Soida 2009, A&A 498L, 21
Kulesza-Żydzik et al. 2010 send to publication
MHD code Grzegorz Kowal
First paper:1.2 x 1011 Msun
sizes (X, Y, Z) – 20 kpc x 20 kpc x 5 kpc,resolution: 512 x 512 x 129 (39 pc) size of bar 4 x 2 x 2 kpc
Second experiment:1.75 x 1011 Msun
sizes: 30 kpc x 30 kpc x 7.59kpcresolution 512 x 512 x 128 (59 pc)size of bar 6 x 3 x 3 kpc
Resonanses
ILR 0.24 kpc, 4.64 kpcCR 11.39 kpc OLR > 15 kpc
ILR 0.33 kpc, 3.06 kpc
CR 6.9 kpc
OLR = 10.44 kpc
ILR 0.69 kpc, 1.31 kpc
CR 3.93 kpc
OLR = 5.81 kpc
Bars with CR driven dynamo Cosmic rays are included to calculate polarization maps
Total magnetic energy
Spirals and tidal forcesr50a00 r50a60
Resolution 256 x 256 x 6430 kpc x 30 kpc x 7.5 kpcTotal mass: 810 x 109 Msun the second galaxy1010 Msun
No CR driven dynamo
Conclusions
In calculations of magnetic field evolution in barred galaxies our model reproduces large-scale structuresof magnetic field observed in such galaxies.
In the same time our simulations solve the problem ofmagnetic arms shift to inter-arm region.
Our second experiment shows that under influence of tidal forces galaxies form magnetic and spiral arms.
It also reproduces large-scale structures of magnetic field observed in spiral galaxies.
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