LOFAR imaging of Cygnus A - direct detection of a turnover in the hotspot radio spectra

J.P. McKean, L.E.H. Godfrey, S. Vegetti, M.W. Wise, R. Morganti, M.J. Bentum, M.J. Hardcastle, D. Rafferty, J. Anderson, I.M. Avruch, R. Beck, M.E. Bell, I. van Bemmel, G. Bernardi