A 42.3-43.6 GHz SPECTRAL SURVEY OF ORION BN/KL: FIRST DETECTION OF THE ν=0 J=1-0 LINE FROM THE ISOTOPOLOGUES 29SiO AND 30SiO

We have surveyed molecular line emission from Orion BN/KL from 42.3 to 43.6 GHz with the Green Bank Telescope. Sixty-seven lines were identified and ascribed to 13 different molecular species. The spectrum at 7 mm is dominated by SiO, SO2, CH3OCH3, and C2H5CN. Five transitions have been detected from the SiO isotopologues (SiO)-Si-28, (SiO)-Si-29, and (SiO)-Si-30. We report here for the first time the spectra of the (SiO)-Si-29 and (SiO)-Si-30 nu = 0 J = 1-0 emission in Orion BN/KL, and show that they have double- peaked profiles with velocity extents similar to the main isotopologue. The main motivation for the survey was the search of high-velocity (100-1000 km s(-1)) outflows in the BN/KL region as traced by SiO Doppler components. Some of the unidentified lines in principle could be high-velocity SiO features, but without imaging data their location cannot be established. Wings of emission are present in the v = 0 (SiO)-Si-28, (SiO)-Si-29, and (SiO)-Si-30 profiles, and we suggest that the v = 0 emission from the three isotopologues might trace a moderately high-velocity (similar to 30-50 km s(-1)) component of the flows around the high-mass protostar Source I in the Orion BN/KL region. We also confirm the 7 mm detection of a complex oxygen-bearing species, acetone (CH3COCH3), which has been recently observed toward the hot core at 3 mm, and have found further indications of the presence of long cyanopolyynes (HC5N and HC7N) in the quiescent cold gas of the extended ridge.