We fitted the line profile with two Gaussian components, one in emission and one in absorption. However, the fit is strongly biased by the line wings and thus the resulting virial mass is most probably overestimated. Negative contours are dashed. Symbols are as in Fig. In the following we propose an interpretation of these findings.
Arrows show the gas velocity with respect to the clump .
The dashed arrows represent the gas seen in absorption toward the UC H II . 1 of Kurtz et al. 10 also show blueshifted gas emission toward the same direction, suggesting that the gas behind the H II region is moving towards the observer. This implies that the absorbing gas is moving along the line of sight towards the UC H II region. As shown in the sketch in Fig.