Thermal Radiation

Emitted radiation, the characteristics of which depend on the temperature of the source. BlackbodyIdeal object that is a perfect absorber of light and also a perfect emitter of light. A perfect black body will absorb all radiation that falls on it, and will emit radiation that has a continuous spectrum determined only by the temperature of the black body: Where, T is the radiation emitted by stars and heated dust, and thermally excited spectral line emission are the two primary sources of thermal radiation in galaxies.