Collisional excitation of sulfur dioxide in cold molecular clouds J. Cernicharo, A. Spielfiedel, C. Balança, F. Dayou, M.-L. Senent, N. Feautrier, A. Faure, L. Cressiot-Vincent, L. Wiesenfeld and J. R. Pardo A&A, 531 (2011) A103 Published online: 21 June 2011 DOI: 10.1051/0004-6361/201016216