The outflow in Mrk 509 - A method to calibrate XMM-Newton EPIC-pn and RGS R. G. Detmers, J. S. Kaastra, E. Costantini, F. Verbunt, M. Cappi and C. de Vries A&A, 516 (2010) A61 Published online: 28 June 2010 DOI: 10.1051/0004-6361/200913879