A KINEMATIC STUDY OF ORION NEBULA IN THE EMISSION-LINE [S-II] 6731 ANGSTROM

Fabry-Perot Interferometric observations were made on Orion Nebula in the forbidden emission line [S II] 6731 angstrom line. The observed fi eld is about 6' x 6' on the face of the nebula and it covers the Orion Trapezium stars and the nearby regions. The relative line of sight ve locities which denote the average deviations from the systematic veloc ities were derived at a large number of points in the nebula. Velociti es were found to show a gradient towards the north of Trapezium stars. Large blue shifted velocities were found at the nebular boundaries, p robably associated with the ionization fronts. The observed velocities , in general, show agreement with the flow model of Balick, Gull and S mith (1980).