Rocket Measurement of the Cosmic Background Submillimeter Spectrum

Abstract

Measurements of the spectrum of the night sky have been made in the wave-number region 5 to 35 ${\mathrm{cm}}^{-1\mathrm{}}$ with use of a liquid-helium-cooled rocket-borne interferometer. The observed spectrum deviates from a 2.7-K Planck spectrum, there being a deficit of energy between 5 and 11 ${\mathrm{cm}}^{-1\mathrm{}}$ and an excess at higher wave numbers.