350
µm Molecular Line Survey of Orion KL
Astronomers reported an
unbiased spectral line survey of Orion KL throughout the 350 μm band
(from 795 to 903 GHz). This is the first systematic study of molecular
radiation in this frequency range. A total of 541 features, resulting
from 929 transitions from a total of 26 species, have been detected.
High-excitation transitions from CH3OH, CH3CN,
H2CO, HNCO, and C2H5CN indicate the
presence of a very hot (~250 K) component at the systemic velocity
characteristic of the Hot Core. Physical parameters (column density and
rotational temperature) relative to a number of species have been
estimated by fitting, in the LTE approximation, the whole 100 GHz
spectrum at once, thus taking line blending and optical depth effects
properly into account. We also report the tentative detection, for the
first time outside the Galactic center region, of the radical
NH2, one of the building blocks of the chemistry of
ammonia. The results were published by Comito
et al 2005 in Astrophysical Journal Supplement Series.
Figure 1. A spectrum towards Orion KL throughout the 350 micron band
(from 795 to 903 GHz).