Submillimeter heterodyne detection of interstellar carbon monoxide at 434 micrometers.
A submillimeter heterodyne radiometer, developed for astronomical applications, uses an optically pumped laser local oscillator and a quasi-optical Schottky diode mixer. The resultant telescope-mounted system, which has a noise temperature less than 4000 K (double sideband) and high frequency and spatial resolution, has been used to detect the J = 6 --> 5 rotational transition of carbon monoxide at 434 micrometers in the Orion molecular cloud. The measurements, when compared with previous millimeter-wave data, indicate that the broad carbon monoxide emission feature is produced by an optically thin gas whose temperature exceeds 180 K.
Fetterman
H R
HR
Koepf
G A
GA
Goldsmith
P F
PF
Clifton
B J
BJ
Buhl
D
D
Erickson
N R
NR
Peck
D D
DD
McAvoy
N
N
Tannenwald
P E
PE