Measuring magnetic fields from water masers in the synchrotron protostellar jet in W3(H2O) C. Goddi, G. Surcis, L. Moscadelli, H. Imai, W. H. T. Vlemmings, H. J. van Langevelde and A. Sanna A&A, 597 (2017) A43 Published online: 21 December 2016 DOI: 10.1051/0004-6361/201629321