Spatially extended OH+ emission from the Orion Bar and Ridge F. F. S. van der Tak, Z. Nagy, V. Ossenkopf, Z. Makai, J. H. Black, A. Faure, M. Gerin and E. A. Bergin A&A, 560 (2013) A95 Published online: 11 December 2013 DOI: 10.1051/0004-6361/201322164