12 CO, 13CO, AND C18 OBSERVATIONS TOWARD OMC-1

Abstract

Interstellar cabon monoxide and its isotopes were observed with the 13.7m radio telescope of the Daeduk Radio Astronomy Observatory toward Orion Molecular Cloud-1 (OMC-1). We derive the excitation temperature, optical depth, column density, and isotopic abundance ratios from the observed lines of 12CO, 13CO, and C18O inside of the region of 11Cx11C. The optical depths of 13CO were obtained to be 0.1~0.4, while those of C18 to be 0.01~0.03. The isotopic ratios 12C/13C were also estimated to be 2~60. We could not find the radial isotopic ratio 12C/13C gradient in the OMC-1.

Keywords

• radio observation
• molecular cloud
• OMC-1