Updated hardware on existing radio telescopes as well as the upcoming generation of telescope arrays like ASKAP, MeerKAT, SKA or LOFAR allow the observer to record a vast number of spectral channels. Applying a Fourier transform to this spectro-polarimetric data of radio continuum emission in turn provides a “Faraday spectrum”. This spectral data embodies complex information about the magneto-ionic medium along the line of sight, and within the telescope beam. A reliable detection of three-dimensional magnetic field structures, e.g. in spiral galaxies or galaxy clusters, will require the development of a “Faraday tomography” method based on the analysis of data cubes spanned by two space coordinates and a “Faraday depth” dimension.
Motivation and Outline
Applying new powerful methods based on rotation measure synthesis will require a strong intuition for interpreting the obtained Faraday spectrum. One guiding principle in exploring the range of applicability and limits of the method will be to use simple synthetic data sets. Working with a single line-of-sight towards a background source, we plan to study the signatures created by e.g. multiple Faraday screens. Complications are expected when considering more complex sight lines, e.g. including regions with significant synchrotron emissivity. Further topics will include artificial polarization maps from dynamo simulations, and statistical analysis of data cubes of multi-phase ISM turbulence with realistic cosmic ray energy distributions. Studying these artificial observations, we aim to already shape an image of the new exciting physics to be revealed by upcoming instruments.
The workshop aims to develop essential tools for interpreting polarization data provided by current and future radio telescopes. Specifically addressing the interface between theoretical modelling and observation, we will focus on effective ways to compare observational data with simulation results. To facilitate the exchange of ideas, we plan to have short talks in the morning and hands-on sessions and informal discussions in the afternoon. Registration via the application page.
Scientific Organizing Committee
- Sui Ann Mao (NRAO/U of Wisconsin Madison)
- Cathy Horellou (Chalmers Göteborg)
- Oliver Gressel (Nordita Stockholm)
- Bryan Gaensler (The University of Sydney)
- Andrew Fletcher (Newcastle University)
- Axel Brandenburg (Nordita Stockholm)
- Rainer Beck (MPIfR Bonn)
||The dirty data cube used for George's RM-clean tutorial.