Broadband radio spectro-polarimetric observations of high-Faraday-rotation-measure AGN Alice Pasetto, Carlos Carrasco-González, Shane O’Sullivan, Aritra Basu, Gabriele Bruni, Alex Kraus, Salvador Curiel and Karl-Heinz Mack A&A, 613 (2018) A74 Published online: 04 June 2018 DOI: 10.1051/0004-6361/201731804