Pure Rotational Spectra of CO, NO, and N2O between 100 and 600 Microns

The pure rotational absorption lines of carbon monoxide (CO) for J = 3 to J = 23, of nitrous oxide (N2O) for J = 19 to J = 40, and of nitric oxide (NO) for J = 5½ to J = 24½ have been observed for the first time. The possibility of using lines of CO and N2O for calibrating a far infrared spectrograph is considered. The pure rotational absorption spectrum of NO yields rotational constants of the molecule in the ground state.