THE S-140 L-1204 COMPLEX - RADIO RECOMBINATION LINES OF HYDROGEN, CARBON AND SULFUR/

We have used the Effelsberg 100-m telescope to observe the hydrogen an d carbon 165 alpha and 166 alpha radio recombination lines towards the S 140/L 1204 complex. In addition to the transitions known from earli er observations, we detect a feature due to ionized sulphur. On the ba sis of the observed H line parameters, we conclude that the emission n ebula S 140 is only a part of a larger partially obscured H II region which has an electron temperature of 6400 K and an electron density of order 10 cm(-3). The obscured fraction of the H II region appears to be either behind or partially immersed in the molecular and C II regio ns. We derive parameters for the C II region by combining our results with measurements of the C II 158 mu m fine structure line by Boreiko et al. (1990) and conclude that the temperature is in the range 75-200 K whereas the electron density is in the range 0.5-9 cm(-3). If there is pressure equilibrium between H II and C II gas, then the lower val ues of the temperature and density are preferable.