Cluster Magnetic Fields from Galactic Outflows - AstrophysicsReport as inadecuate

Cluster Magnetic Fields from Galactic Outflows - Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: We performed cosmological, magneto-hydrodynamical simulations to follow theevolution of magnetic fields in galaxy clusters, exploring the possibility thatthe origin of the magnetic seed fields are galactic outflows during thestar-burst phase of galactic evolution. To do this we coupled a semi-analyticalmodel for magnetized galactic winds as suggested by \citet{2006MNRAS.370

319B}to our cosmological simulation. We find that the strength and structure ofmagnetic fields observed in galaxy clusters are well reproduced for a widerange of model parameters for the magnetized, galactic winds and do only weaklydepend on the exact magnetic structure within the assumed galactic outflows.Although the evolution of a primordial magnetic seed field shows no significantdifferences to that of galaxy clusters fields from previous studies, we findthat the magnetic field pollution in the diffuse medium within filaments isbelow the level predicted by scenarios with pure primordial magnetic seedfield. We therefore conclude that magnetized galactic outflows and theirsubsequent evolution within the intra-cluster medium can fully account for theobserved magnetic fields in galaxy clusters. Our findings also suggest thatmeasuring cosmological magnetic fields in low-density environments such asfilaments is much more useful than observing cluster magnetic fields to infertheir possible origin.

Author: J. Donnert, K. Dolag, H. Lesch, E. Müller


Related documents