A spectral survey of the Orion Nebula from 455-507 GHz

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 similar to 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, SO2 and CH3OH and large organic molecules such as (CH3)(2)O, CH3CN, C2H3CN, C2H5CN and HCOOCH3 which make up similar to72% of the total number of lines; unidentified lines similar to13%; and other lines the remaining similar to15% 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.