RAPTOR - I. Time-dependent radiative transfer in arbitrary spacetimes T. Bronzwaer, J. Davelaar, Z. Younsi, M. Mościbrodzka, H. Falcke, M. Kramer and L. Rezzolla A&A, 613 (2018) A2 Published online: 15 May 2018 DOI: 10.1051/0004-6361/201732149