Published online by Cambridge University Press: 04 August 2017
High resolution images of the Orion Nebula in the millimeter wave emission lines of CS and CO taken with the 45-m telescope at Nobeyama are presented. They cover a field approximately 400″ square with a 15″ – 34″ resolution and reveal a wealth of information on kinematic and density structures. The images of the J=1-0 (49 GHz) and J=2-1 (98 GHz) lines of CS show a long (>1 pc) and narrow (∼0.1 pc) N-S ridge of dense molecular gas. On the ridge, two major clumps are recognized; one is associated with the KL object and the other is 100″ south of it. The images of the J=1-0 (115 GHz) CO line indicate interaction between the molecular cloud and the H II region formed by the Trapezium stars. Bright CO emission is found towards the edges of the denser part of the H II region delineated by radio continuum emission. The CO emission coincides with the emission of vibrationally excited H2 and the 3.3 μm dust emission feature. The CO images reveal filamentary structures (“streamers”) stretching radially from the KL region. On the streamers there are Herbig-Haro objects moving away from the KL region. They may be tracers of weak interaction between the ambient molecular gas and mostly unseen, highly collimated, high-velocity (>200 km/s) jets.