Molecular Clouds in Cepheus and Cassiopeia

Abstract

A large-scale 13CO(J = 1-0) survey for nearby molecular clouds was performed toward the Cepheus and Cassiopeia regions (100° < l < 130° and -10° < b < 20°) with the velocity coverage of -40 < VLSR < +20 km s-1 by using the two 4 m millimeter-wave telescopes at Nagoya University. An area of 866 square degrees was covered at an 8' grid spacing with a 27 beam, and 48,750 positions were observed. Significant 13CO emission (≥1.8 K km s-1 = 3 σ) is detected at 1015 positions. On the basis of the 13CO data, 188 distinct 13CO clouds are identified whose total mass is 1.0 × 105 M☉. Physical properties of the 13CO clouds such as molecular column densities, sizes, and masses are derived for each cloud. Astronomical objects associated with the 13CO clouds were searched for in the literature: 10 H II regions, eight reflection nebulae, 23 T Tauri type stars, 28 molecular outflows, and 125 IRAS point sources selected as candidates for protostars are likely to be associated with the 13CO clouds.