A multiwavelength study of the S106 region

The molecular cloud associated with Sharpless 106 has been studied in a variety of (sub)millimeter CO rotational lines on angular resolution scales from 11'' to 80''. We used the KOSMA 3 m telescope to obtain an extended 12CO $J=3$ $\to$2 map, from which we calculate a total mass of 2000 $M_\odot$ and an average density of $1.4\times10^3$ cm-3 for the molecular cloud. The peak intensity region around the massive young star S106 IR was observed in 13CO $J=6$ $\to$5 and 3$\to$2 with KOSMA and in isotopomeric low-J CO lines with the IRAM 30 m telescope. A clump decomposition made for several lines yields a common clump-mass spectral index of $\alpha=1.7$, illustrating the self-similarity of the detected structures for length-scales from 0.06 to 0.9 parsec. All 12CO and 13CO line profiles within approximately 2' around S106 IR show blue wing emission and less prominent red wing emission, partly affected by self-absorption in colder foreground material. We attribute this high-velocity emission to the ionized wind of S106 IR driving a shock into the inhomogeneous molecular cloud. We do not find evidence for a smooth or fragmented disk around S106 IR and/or an expanding ring in the observed CO emission distribution. The excitation conditions along a cut through the molecular cloud/H I