INFRARED SPECTRA OF THE AIRGLOW AND AURORA BETWEEN 0.9 $\mu$ AND 2.0 $\mu$

Abstract

“Spectra of the airglow and aurora from 0.9 $\mu$ to 2.0 $\mu$ have been obtained with a PbS cell infrared spectrometer which is designed to work at low resolution (25\^{\prime}^{\prime}{A} to 200\^{\prime\prime}{A}) with very weak sources. Auroral spectra have been obtained which show the $0-0 N^{+}_{2}$ Meinel band at $1.11 \mu$ and further bands of the $\Delta$ $v=-1$ sequence of this system between $1.5 \mu$ and $1.6 \mu$. In the twilight airglow spectrum the $0-1$ band of the $^{1}\Delta_{g}-^{1}\Sigmma_{g}^{+}$ atmospheric $O_{2}$ system has been detected as an emission feature which decays in a way which suggests that band is emitted as a result of a phosphorescent excitation by solar radiation. The night airglow spectrum in this region consists entirely of the intense $\Delta$ $v=2$ and $\Delta$ $v=3$ sequences of Meinel OH vibration-rotation bands. Absolute intensity measurements have been made of the bands studied.”