Statistical methods for the analysis of rotation measure grids in large scale structures in the SKA era
Paper in proceedings, 2015
Determining magnetic field properties in different environments of the cosmic large-scale structure as well as their evolution over redshift is a fundamental step toward uncovering the origin of cosmic magnetic fields. Radio observations permit the study of extragalactic magnetic fields via measurements of the Faraday depth of extragalactic radio sources. Our aim is to investigate how much different extragalactic environments contribute to the Faraday depth variance of these sources. We develop a Bayesian algorithm to distinguish statistically Faraday depth variance contributions intrinsic to the source from those due to the medium between the source and the observer. In our algorithm the Galactic foreground and the measurement noise are taken into account as the uncertainty correlations of the galactic model. Additionally, our algorithm allows for the investigation of possible redshift evolution of the extragalactic contribution. This work presents the derivation of the algorithm and tests performed on mock observations. With cosmic magnetism being one of the key science projects of the new generation of radio interferometers we have made predictions for the algorithm's performance on data from the next generation of radio interferometers. Applications to real data are left for future work.
Author
V. Vacca
Max Planck Society
N. Oppermann
Canadian Institute for Theoretical Astrophysics
T.A. Enßlin
Max Planck Society
Ludwig-Maximilian University of Munich
M. Selig
Max Planck Society
Ludwig-Maximilian University of Munich
H. Junklewitz
Argelander-Institut für Astronomie
M. Greiner
Ludwig-Maximilian University of Munich
Max Planck Society
J. Jasche
Centre national de la recherche scientifique (CNRS)
C.A. Hales
National Radio Astronomy Observatory
National Radio Astronomy Observatory Socorro
M. Reinecke
Max Planck Society
E. Carretti
CSIRO Astronomy and Space Science
L Ferrari
Université Nice Sophia Antipolis (UNS)
C. Ferrari
Istituto di Radioastronomia
G. Giovannini
University of Bologna
Istituto di Radioastronomia
Cathy Horellou
INAF Osservatorio Astronomico di Cagliari
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
S. Ideguchi
Kumamoto University
M. Johnston-Hollitt
Victoria University of Wellington
M. Murgia
INAF Osservatorio Astronomico di Cagliari
R. Paladino
Istituto di Radioastronomia
University of Bologna
R. Pizzo
Netherlands Institute for Radio Astronomy (ASTRON)
A. Scaife
University of Southampton
Proceedings of Science
18248039 (eISSN)
114Subject Categories
Physical Sciences
Astronomy, Astrophysics and Cosmology
Roots
Basic sciences