1995A&A...302..202C

The Manchester echelle spectrometer has been used on the William Herschel telescope at a resolution of 10km/s to observe the kinematics of a group of high-speed (≥70km/s) knots close to the ionizing O & B stars in the core of the Rosette nebula. A data cube composed of spatially resolved [OIII]5007A line profiles was generated by stepping a 5-element, long, multi-slit across the sky. High-speed, blue-shifted, filaments linking two of the knots have been revealed in the subsequent velocity imagery. Of particular interest is a high-speed bow-shaped filament surrounding the highest speed knot C. This filament is exceptionally bright in the [OIII]5007A line. Various mechanisms for the creation of these curious high-speed phenomena are considered in the light of the wealth of data now becoming available on localised high-speed flows in HII regions generally. The winds from the central O stars as the driving force are now discounted. The predictions of a model involving a bullet or flowing finger of molecular gas are promising but not completely consistent with the observed phenomena. The identities of possible local, or more energetic, displaced, driving sources are discussed. None of these explanations, however, are conclusive and further observations are proposed.