Deuterium fractionation in the Horsehead edge J. Pety, J. R. Goicoechea, P. Hily-Blant, M. Gerin and D. Teyssier A&A, 464 3 (2007) L41-L44 Published online: 29 January 2007 DOI: 10.1051/0004-6361:20067009