WSRT Faraday tomography of the Galactic ISM at lambda similar to 0.86 m - First results for a field at (l, b) = (181 degrees, 20 degrees)

D. H. F. M. Schnitzeler*, P. Katgert, A. G. de Bruyn

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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Aims. We investigate the distribution and properties of Faraday rotating and synchrotron emitting regions in the Galactic ISM in the direction of the Galactic anti-centre.

Methods. We apply Faraday tomography to a radio polarization dataset that we obtained with the WSRT. We developed a new method to calculate a linear fit to periodic data, which we use to determine rotation measures from our polarization angle data. From simulations of a Faraday screen + noise we could determine how compatible the data are with Faraday screens.

Results. An unexpectedly large fraction of 14% of the lines-of-sight in our dataset show an unresolved main component in the Faraday depth spectrum. For lines-of-sight with a single unresolved component we demonstrate that a Faraday screen in front of a synchrotron emitting region that contains a turbulent magnetic field component can explain the data.

Original languageEnglish
Pages (from-to)L21-L24
Number of pages4
JournalAstronomy & astrophysics
Issue number2
Publication statusPublished - Aug-2007


  • magnetic fields
  • radio continuum : ISM
  • ISM : magnetic fields
  • ISM : structure
  • techniques : polarimetric
  • techniques : miscellaneous
  • MHZ

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