The results of a submillimetre wavelength spectral line survey between 455.1 – 507.4 GHz of the Orion-KL hot cloud core are reported .
A total of 254 lines were detected to a main beam brightness temperature sensitivity T _ { mb } \sim 1 - 3 K. The detected lines are identified as being associated with 30 different molecular species or their isotopomeric variants .
The strongest line detected was the J = 4–3 transition of the CO molecule .
Apart from abundant diatomic rotors such as CO and CS , the spectrum is dominated by SO , SO _ { 2 } and CH _ { 3 } OH and large organic molecules such as ( CH _ { 3 } ) _ { 2 } O , CH _ { 3 } CN , C _ { 2 } H _ { 3 } CN , C _ { 2 } H _ { 5 } CN and HCOOCH _ { 3 } which make up \sim 72 % of the total number of lines ; unidentified lines \sim 13 % ; and other lines the remaining \sim 15 \% of the total .
Rotational temperatures and column densities derived using standard rotation diagram analysis techniques were found to range from 70 - 300 K , and 10 ^ { 14 } – 10 ^ { { 17 } } cm ^ { 2 } respectively .