Structure, dynamical impact and origin of magnetic fields in nearby galaxies in the SKA era
Paper in proceedings, 2015

Magnetic fields are an important ingredient of the interstellar medium (ISM). Besides their importance for star formation, they govern the transport of cosmic rays, relevant to the launch and regulation of galactic outflows and winds, which in turn are pivotal in shaping the structure of halo magnetic fields. Mapping the small-scale structure of interstellar magnetic fields in many nearby galaxies is crucial to understand the interaction between gas and magnetic fields, in particular how gas flows are affected. Elucidation of the magnetic role in, e.g., triggering star formation, forming and stabilising spiral arms, driving outflows, gas heating by reconnection and magnetising the intergalactic medium has the potential to revolutionise our physical picture of the ISM and galaxy evolution in general. Radio polarisation observations in the very nearest galaxies at high frequencies (3 GHz) and with high spatial resolution (500) hold the key here. The galaxy survey with SKA1 that we propose will also be a major step to understand the galactic dynamo, which is important for models of galaxy evolution and for astrophysical magnetohydrodynamics in general. Field amplification by turbulent gas motions, which is crucial for efficient dynamo action, has been investigated so far only in simulations, while compelling evidence of turbulent fields from observations is still lacking.

Magnetic fields

Polarization

Square Kilometer Arrray

Author

R. Beck

Max Planck Society

D. Bomans

Ruhr-Universität Bochum

S. Colafrancesco

University of Witwatersrand

R.J. Dettmar

Ruhr-Universität Bochum

K. Ferriere

University of Toulouse

A. Fletcher

Newcastle University

G. Heald

Netherlands Institute for Radio Astronomy (ASTRON)

V. Heesen

University of Southampton

Cathy Horellou

Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics

M. Krause

Max Planck Society

Y.-Q. Lou

Tsinghua University

S. A. Mao

Max Planck Society

R. Paladino

INAF OAS Bologna

E. Schinnerer

Max Planck Society

D. Sokoloff

Moscow State University

J. Stil

University of Calgary

F. Tabatabaei

Max Planck Society

Proceedings of Science

18248039 (eISSN)

094

Subject Categories

Physical Sciences

Astronomy, Astrophysics and Cosmology

Roots

Basic sciences

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