2.3 μm CO emission and absorption from young high-mass stars in M 17 V. H. Hoffmeister, R. Chini, C. M. Scheyda, D. Nürnberger, N. Vogt and M. Nielbock A&A, 457 3 (2006) L29-L32 Published online: 12 September 2006 DOI: 10.1051/0004-6361:20065946