Molecular oxygen in the ρ Ophiuchi cloud B. Larsson, R. Liseau, L. Pagani, P. Bergman, P. Bernath, N. Biver, J. H. Black, R. S. Booth, V. Buat, J. Crovisier et al. (48 more) A&A, 466 3 (2007) 999-1003 Published online: 24 April 2007 DOI: 10.1051/0004-6361:20065500