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

M51, total power 6cm +B-vectors, VLA + Effelsberg + HST optical image

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

Bars without CR driven dynamo

Initial curve of rotation

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

r50a30

r50a30

r100a00

r50a30

Densities cuts

r50a60r100a30 r50a00

r50a30

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.

Invitations to posters:

Siejkowski et al. „Cosmic ray driven dynamo in the ISM of irregular galaxies”

Kulpa-Dybeł et al. „Can turbulent reconnection be fast in 2D”

Kulpa-Dybeł et al. „3D MHD simulations of magnetic field and radio polarization of barred galaxies”