The IRAM 3O-m telescope has been used to obtain a fully sampled 29" resolution map of the J =5-4 (K = 0 to 3) lines of methyl acetylene (CH3C2H) in a 2' x 4' region in OMC1. This map shows a number of clumps along the ridge of OMC1. The kinetic temperatures and CH3C2 Hcolumn densities are derived at most positions using the rotation diagram method. Towards IRc2 and towards the positions of four peaks within the J = 5-4 map, the J = 13-12 (K = 0 to 4) lines have been observed with the KOSMA 3-m telescope. The kinetic temperatures (30 to 50 K) and column densities from the J = 13 - 12 lines are consistent with those of J = 5-4 lines. Our analysis shows that the cloud consists of three clumps with velocities (from south to north) 6.5, 8, and 10 km s-1. These clumps overlap near IRc2 and about 60" south of IRc2. These results give no support for a model involving a single rotating cloud near Orion KL.
Astronomy and Astrophysics
- Pub Date:
- September 1993
- ISM: clouds - ISM: individual ohjects: OMC1 - ISM: molecules - radio lines: interstellar