Preliminary Observations of the Far-Infrared Night-Sky Background Radiation

Abstract

We have carried out far-infrared rocket observations in the spectral range from 0.4 to 1.3 mm and have detected a flux of 5 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}9}$ W${/\mathrm{c}\mathrm{m}}^{\ensuremath{-}2}$ sr, with an uncertainty of a factor of 2. The flux is nearly two orders of magnitude greater than that to be expected from a 3\ifmmode^\circ\else\textdegree\fi{}K black cosmic background in this spectral range; its equivalent blackbody temperature would correspond to 8.3\ifmmode^\circ\else\textdegree\fi{}${\mathrm{K}}_{\ensuremath{-}1.3}^{+2.2}$\ifmmode^\circ\else\textdegree\fi{}K.