Revealing the magnetic field in a distant galaxy cluster: discovery of the complex radio emission from MACS J0717.5 +3745A. Bonafede, L. Feretti, G. Giovannini, F. Govoni, M. Murgia, G. B. Taylor, H. Ebeling, S. Allen, G. Gentile and Y. PihlströmA&A, 503 3 (2009) 707-720DOI: https://doi.org/10.1051/0004-6361/200912520