Project Part A3: Magnetization of the IGM: role of starburst dwarf galaxies

Persons involved


With LOFAR becoming operational, a great opportunity exists to shed light on a problem of cosmological significance. Diffuse radio synchrotron emission not associated to any obvious discrete sources as well as Faraday rotation in clusters of galaxies both indicate that the IGM and ICM are pervaded by a weak magnetic field, along with a population of relativistic particles. Both particles and fields must have been injected into the IGM either by Active Galactic Nuclei (AGN) or by normal star-forming galaxies. Excellent candidates for the latter are starburst dwarf galaxies, which in the framework of hierarchical structure formation must have been around in large numbers. If this is true, one should be able to detect extended synchrotron haloes of formerly highly relativistic particles around local starburst or post-starburst dwarf galaxies. With LOFAR, we can find these out to at least the Coma Cluster and beyond.