opp14_foreground.fits -- Obtained from https://wwwmpa.mpa-garching.mpg.de/ift/faraday/2014/index.html

Download this file for the 2022 version
faraday2020v2.fits -- Obtained from https://wwwmpa.mpa-garching.mpg.de/~ensslin/research/data/faraday2020.html
  Also available here:  https://drive.google.com/file/d/1m_oEdjCwrnHFkWV8SI1EGpa-xTEB_b7k/view?usp=sharing
