Rosette Nebula: RRL observations of 92α transition and the modelling

Abstract Observations of H 92 α radio recombination line (RRL) and continuum emission were made towards three Celnik positions of the Rosette Nebula . The electron temperature T e (LTE) was derived for each position giving an average value of 7980±580 K. A non-LTE modelling was made which could describe the dependence of line contrast ( T L / T C ), T e (LTE) and line width on quantum number ( n ). The modelling together with a review of available data show that the Rosette Nebula should contain clumps with densities up to ∼10 3 cm −3 . The unexpected V LSR measured at one of the three positions could be interpreted as a possible jet, or some dense compact part (clump) of the HII region, moving toward the observer.