The TeV blazar Markarian 421 at the highest spatial resolution M. G. Blasi, R. Lico, M. Giroletti, M. Orienti, G. Giovannini, W. Cotton, P. G. Edwards, L. Fuhrmann, T. P. Krichbaum, Y. Y. Kovalev et al. (7 more) A&A, 559 (2013) A75 Published online: 18 November 2013 DOI: 10.1051/0004-6361/201321858