A submillimeter exponential disk in M 51: Evidence for an extended cold dust disk R. Meijerink, R. P. J. Tilanus, C. P. Dullemond, F. P. Israel and P. P. van der Werf A&A, 430 2 (2005) 427-434 Published online: 20 January 2005 DOI: 10.1051/0004-6361:20040469