1994A&A...286..555R

The star formation region DR 21(OH) was observed in the J=5-4 transitions of CS and C³⁴S, and in several J=5-4 transitions of methanol. High velocity wings are detected in CS towards the main DR 21(OH) peak, extending over 80km/s. They are very faint, and the outer wings are detected only at the centre position. Since the outflow is not seen in the CO J=1-0 or 2-1 transitions, the CS observations suggest that this is a young, compact, dense and hot outflow. Many of the known NH₃ cores are also seen in CS and methanol. Three known submm-continuum sources, DR 21(OH)S, DR 21(OH)SW, and DR 21(OH)NW, are surprisingly faint in the CS J=5-4 line, probably because the gas, though sufficiently dense, is too cold to fully excite the CS J=5-4 transition. They are, however, strong in methanol. An additional source, DR 21(OH)SE, is strong in CS but weak in methanol. The methanol lines were interpreted with an LTE analysis to estimate rotational temperatures and column densities at the main peaks, and the results discussed in the context of chemical models.