A spectral survey of the Star Forming Core 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 ~ 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_3OH and large organic molecules such as (CH_3)_2O, CH$_3CN, C_2H_3CN, C_2H_5CN and HCOOCH_3 which make up ~ 72% of the total number of lines; unidentified lines ~ 13%; and other lines the remaining ~ 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. Accepted by Astronomy & Astrophysics 22 May 2003