Cosmic Magnetism
Magnetic fields on large scales are observed within galaxies,
along galactic outflows and even within the intra-cluster medium (ICM),
filling the space inside galaxy clusters. It is expected that also the
diffuse baryons within filaments and maybe even in voids -- which are the
largest structures observed in the Universe -- are magnetized. However,
despite their importance for various transport processes, our understanding
of the origin, evolution and interplay of magnetic fields with structure
formation is still very limited.
Therefore, numerical experiments are a key tool for understanding the build up of
large scale magnetic fields. They also enable the prediction of the expected properties of the
magnetic field among different classes of objects (voids, filaments or
galaxy clusters). Numerical simulations of the formation of cosmological
structures and predictions of their magnetic field properties allow
to put constraints on different models for the origin of cosmic magnetism.
This also puts constraints onto the various mechanisms proposed for the magnetic seed
fields, and relates the evolution of the magnetic field structure to the dynamical
state of the cosmic structures. Particularly in case of galaxy clusters this allows
to put additional constraints on the presence of cosmic ray protons by comparing
in detail the induced radio emission in such simulations with observations.
Additionally, such simulations can be used to constrain the transport and the deflection
of ultra high energy particles (e.g. protons, photons) within the large scale
structures of the universe.
K.Dolag