We have constructed the Mount Fuji submillimeter-wave telescope at Nishiyasugawara (alt. 3725 m) near the summit of Mt. Fuji (alt. 3774 m). Thanks to the excellent condition of Mt. Fuji, we have successfully carried out the [CI] survey toward more than 40 square degrees of sky, including qrion MC, Taurus MC, Rosetta MC, DR 15, DR 21, NGC 1333, NGC 2264, W 3, W 44, W 51, L 134, p-Oph. Our [CI] survey have revealed that the [CI] 492 GHz emission widely extends to the molecular clouds. The spatial and velocity structures of the [CI] 492 GHz emission resemble those of 13CO J=l-0 in many molecular clouds, implying that [CI] 492 GHz and 13CO J=1-0 are emitted from the same gas. The column density of C° linearly correlates with that of CO up to high Av, suggesting that C° exist in the deep interior of molecular clouds. In several regions, we have found that the distributions of C° and CO are different from each other. The C°-rich area is found in the Hieles' cloud 2. The C+/CO/C° configuration is found in DR 15, p-Oph, M 17, Orion KL, and NGC 1333. These results indicate that an origin of C° is unrelated with the photodissociation process. We discuss the observed C° distributions in relation to the non-equilibrium chemistry.

• TAKESHI SAKA(Nobeyama Radio Observatory/Mount Fuji Submillimeter-wave Telescope Group)
• SATOSHI YAMAMOTO(Department of Physics, The University of Tokyo/Mount Fuji Submillimeter-wave Telescope Group)