Radiative Transfer

Definition

Radiative transfer is the theory describing how electromagnetic radiation is created, transmitted, absorbed, and scattered in a medium such as a planetary atmosphere, stellar photosphere, or interstellar medium. The medium can emit, absorb, and scatter radiation with a behavior that could vary strongly with wavelength according to the different species composing the medium and their physical state.

Overview

In astrophysics, if we except the objects of the solar system visited by probes, the intrinsic properties of a celestial object must be derived from the only available information: the observed radiation. To interpret the spectrum that is emerging from the atmosphere of a planet, an interstellar cloud or from the outer layer of a star, called the photosphere, it is necessary to model not only the production of radiation at any point of the medium but also the way it is locally absorbed or scattered in any direction. The emerging radiation, which the observer will collect,...