The Interstellar Radiation Field and Its Interaction with the Interstellar Matter

Abstract

Most stars emit most of their radiation in the wavelength range between the far ultraviolet (FUV) and near-infrared (IR). Eddington (1926) first estimated for the solar vicinity a mean radiation intensity of the interstellar radiation field (ISRF) equivalent to that of blackbody radiation of ~3 K but with a spectral distribution that can be approximated by ~10,000 K blackbody radiation diluted by a factor ≈ 10−14.