MOLECULAR CLOUDS IN CYGNUS .1. A LARGE-SCALE (CO)-C-13 SURVEY

A large-scale (CO)-C-13(J = 1-0) survey was performed with a 2.'7 angular resolution toward the Cygnus region, using the two 4 m millimeter telescopes at Nagoya University. An area of 432 deg(2) was covered with an 8' grid spacing, and 24,300 positions were observed. Significant (CO)-C-13 emission (>1.2 Kkm s(-1) = 3 sigma) is detected at 2191 positions, corresponding to a detection rate of 9%. On the basis of the (CO)-C-13 data, 159 distinct clouds are identified. Physical properties of these clouds such as molecular column densities, sizes, and masses are derived for the individual clouds. Astronomical objects associated with the molecular clouds were searched for in the literature. Seven H II regions, three SNRs, 45 T Tauri-type stars, 18 molecular outflows, and 215 IRAS point sources selected as candidates for protostars are likely to be associated with the molecular clouds. This paper presents the observational technique used for this survey and a complete list of the detected molecular clouds in Cygnus.