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arXiv · 0901.0116

Global simulations of galactic dynamo driven by cosmic-rays and exploding magnetized stars

Michał Hanasz·Dominik Wóltański·Kacper Kowalik·Rafał Pawłaszek
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Abstract

We conduct global galactic--scale magnetohydrodynamical (MHD) simulations of the cosmic--ray driven dynamo. We assume that exploding stars deposit small--scale, randomly oriented, dipolar magnetic fields into the differentially rotating ISM, together with a portion of cosmic rays, accelerated in supernova shocks. Our simulations are performed with the aid of a new parallel MHD code PIERNIK. We demonstrate that dipolar magnetic fields supplied on small SN--remnant scales, can be amplified exponentially by the CR--driven dynamo to the present equipartition values, and transformed simultaneously to large galactic--scales by an inverse cascade promoted by resistive processes.

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Michał Hanasz, Dominik Wóltański, Kacper Kowalik, Rafał Pawłaszek. 2008-12-31. Global simulations of galactic dynamo driven by cosmic-rays and exploding magnetized stars. https://doi.org/10.1017/s1743921309031275

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