Dense cores in L1204/S140 - Star formation and velocity shifts

We observe the dense gas in the L1204/S140 molecular complex using CS(J = 1-0) and NH3. The large-scale CS(J = 1-0) maps show that L1204 is formed by three filamentary clouds, each being fragmented into cores of a few hundred solar masses and surrounded by low-level emission. The most prominent core is associated with S140, a well-known high-mass star-forming region. The star-forming activity, however, is not restricted to the vicinity of S140, but extends throughout the complex; very red IRAS sources lie close to most of the cores, and molecular outflows have been detected in half of them. The ammonia observations reveal velocity shifts of about 0.5-0.8 km/s in the dense gas inside the cores with embedded stars. These velocity shifts, although small, are systematic and tend to divide the cores into two velocity regimes with little overlap. Fast rotation of the cores or the interaction between the bipolar outflows and the dense gas (or a combination of both) are the most likely causes for these velocity shifts.