A spectral line survey from 138.3 to 150.7 GHz toward Orion-KL

We present the results of a spectral line survey from 138.3 to 150.7 GHz to ward Orion-KL. The observations were made using the 14 m radio telescope of Taeduk Radio Astronomy Observatory. Typical system temperatures were betwe en 500 and 700 K, with the sensitivity between 0.02 and 0.06 K in units of T-A*. A total of 149 line spectra are detected in this survey. Fifty lines have been previously reported; however, we find 99 new detections. Among th ese new lines, 33 are "unidentified," while 66 are from molecular transitio ns with known identifications. There is no detection of H or He recombinati on lines. The identified spectra are from a total of 15 molecular species a nd their isotopic variants. In the range from 138.3 to 150.7 GHz, the stron gest spectral line is the J = 3-2 transition of the CS molecule, followed b y transitions of H2CO, CH3OH, CH3CN, and SO2. Spectral lines from the large organic mol ecules such as CH3OH, CH3OCH3, HCOOCH3, C2H5CN, and CH3CN are prominent, with 80% of the identified lines arising from transitions of the se molecules. The rotational temperatures and column densities are derived using the standard rotation diagram analysis for CH3OH ((CH3OH)-C-13), HCOO CH3, CH3CN, and SO2 at 10-270 K and 0.2-20 X 10(15) cm(-2). These estimates are fairly comparable to the values for the same molecules found in other frequency regions by other studies.