GALACTIC HII-REGIONS AT L=234-DEGREES

We have observed with a Fabry-Perot interferometer in H alpha light 7 fields, 38' x 38' each, covering the galactic HII regions S 299, 300, 302, 305, 306, 307 and 309 (231 degrees < l < 235 degrees, -1 degrees< b < 2 degrees). The Ha profiles consist of emission lines of several layers of ionized gas superimposed along the line of sight, with diffe rent radial velocities. The discrete HII regions of this area may be s eparated into two velocity groups, V-LSR similar to 16 km s(-1) and V- LSR similar to 43 km s(-1). Two of them (S 305 and S 307) show a pecul iar velocity with respect to their associated molecular cloud which ma y be explained by a ''Champagne effect''. The H alpha profiles observe d in zones without HIII region show that there are two layers of diffu se emission all over this galactic area, with the same velocities as t he HII regions. The two groups of ionized gas are associated with gian t molecular clouds of similar velocity. Spectrophotometry of exciting stars of HII regions enables one to determine the distance of both com plexes quite accurately since we average several individual HII region distances. The first complex is found at 2.1 kpc whereas the second o ne is found at 4.2 kpc corresponding to galactocentric distances of 9. 9 and 11.5 kpc with R(o) = 8.5 kpc.