AST/RO observations of atomic carbon near the Galactic center

We present a coarsely sampled map of the region \l\ less than or equal to 2 degrees, \b\ less than or equal to 0.degrees1 in the 492 GHz (P-3(1) --> P -3(0)) fine-structure transition of neutral carbon, observed with the Antar ctic Submillimeter Telescope and Remote Observatory (AST/RO). The distribut ion of [C I] emission is similar on the large scale to that of CO J = 1 --> 0. On average, the ratio of the integrated intensities, I-[C I]/I-12CO, is higher in the Galactic disk than in the Galactic center region. This resul t is accounted for by the absorption of (CO)-C-12 within the clouds located in the outer Galactic disk. The ratio I-[C I]/I-12CO is surprisingly unifo rm over the variety of environments near the Galactic center. On average, [ C I] is optically thin [or as optically thin as (CO)-C-13 (J = 1 --> 0)], e ven in the dense molecular clouds of the Galactic center region.