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)

114

Subject Categories

Physical Sciences

Astronomy, Astrophysics and Cosmology

Roots

Basic sciences

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11/3/2020