Large-scale mapping observations of the C-I P-3(1)-P-3(0) line toward Heiles cloud 2 in the Taurus dark cloud

A distribution of the neutral carbon atom (C I) in Heiles cloud 2 (HCL2) ha s been investigated with the Mount Fuji submillimeter-wave telescope. A reg ion of 1.2 deg(2) covering a whole region of HCL2 has been mapped with the P-3(1)-P-3(0) fine-structure line (492 GHz) of C I. The global extent of th e C I emission is similar to that of (CO)-C-13, extending from southeast to northwest. However, the C I intensity is found to be rather weak in dense cores traced by the J = 1-0 line of (CO)-O-18. On the other hand, strong C I emission is observed in a south part of HCL2 in which the (CO)-O-18 inten sity is fairly weak. The C I/CO abundance ratio is greater than 0.8 for the C I peak, whereas it is 0.1 for the dense cores such as the cyanopolyyne p eak. The C I-rich cloud found in the south part may be in the early evoluti onary stage of dense core formation where C I has not yet been converted co mpletely into CO. This result implies that formation of dense cores is taki ng place from north to south in HCL2.