Magnetic fields in nearby galaxies: Low-frequency radio observations

• Applicants: Dr. Rainer Beck; Professor Dr. Ralf-Jürgen Dettmar
• Subject Area: Astrophysics and Astronomy
• Term: from 2010 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 108727618

The origin of the well organised magnetic fields on galactic scales is a fundamental problem in extragalactic astrophysics. For theoretical models, constraints with regard to the magnetic field strength and orientation on most relevant scales are required, from the smallest scales related to turbulence, to the largest scales related to outflows into the intergalactic environment. Radio continuum observations at low frequencies as provided by LOFAR will allow us to address in particular the latter problem. This Project focuses on investigations of magnetic fields in and around normal spiral galaxies and massive irregular galaxies using low-frequency radio continuum observations with unprecedented angular resolution and sensitivity. At low frequencies the low-energy cosmic-ray electrons trace the magnetic fields to much larger galactic radii, and the analysis of the Faraday rotation is sensitive to much smaller magnetic field strengths than previous methods. Especially, we will analyse the energy gain and loss processes of the relativistic electrons via radio spectral index maps, the strength and structure of magnetic fields in galaxy disks and halos, the bulk speed of the relativistic electrons and their relation to the flow patterns of thermal gas and to the magnetic fields generated by galactic dynamos.

• DFG Programme: Research Units
• Subproject of: FOR 1254: Magnetisation of Interstellar and Intergalactic Media: The Prospects of Low-Frequency Radio Observations
• Participating Person: Privatdozent Dr. Dominik Bomans