Strong CH+ J = 1–0 emission and absorption in DR21 E. Falgarone, V. Ossenkopf, M. Gerin, P. Lesaffre, B. Godard, J. Pearson, S. Cabrit, Ch. Joblin, A. O. Benz, F. Boulanger et al. (23 more) A&A, 518 (2010) L118 Published online: 16 July 2010 DOI: 10.1051/0004-6361/201014671