Physical insights from the spectrum of the radio halo in MACS J0717.5+3745 K. Rajpurohit, G. Brunetti, A. Bonafede, R. J. van Weeren, A. Botteon, F. Vazza, M. Hoeft, C. J. Riseley, E. Bonnassieux, M. Brienza et al. (11 more) A&A, 646 (2021) A135 Published online: 18 February 2021 DOI: 10.1051/0004-6361/202039591