On the luminescence of nitrogen, argon, and other condensed gases at very low temperatures

Abstract

One of the outstanding problems awaiting solution in the field of spectroscopy is the origin of certain unknown lines in the spectra of nebulæ. Another has to do with the origin of the famous green line, λ = 5577Å in the spectrum of the auroral light. As regards the solution of the first it has been suggested that the unknown nebular lines may be found to originate in the radiation emitted by helium in the molecular- state, provided the gas is stimulated to the emission of radiation under conditions of suitably low pressures and suitably low temperatures. It has also been suggested that the unknown nebular lines may originate in radiation from a gas consisting of molecules formed of atoms of hydrogen and of helium, provided this gas is subjected to suitable conditions of pressure, temperature, and excitation.