The expression “radiative processes” encompasses all the various physical processes by which a medium releases energy in the form of electromagnetic radiation. At the microscopic level, this involves the emission of a photon by an elementary particle, as the result of specific interactions with other particles or particular conditions of temperature, acceleration, and/or excitation. Several radiative processes producing continuum emission can be identified: on one side, blackbody and bremsstrahlung radiation which are the source of thermal emission and, on the other side, cyclotron, gyrosynchrotron, and synchrotron emission, which are linked to the spiraling of charged particles in a magnetic field and considered as nonthermal processes. Note that we do not consider in this entry spectral line emission, which results from quantum transitions between energy levels of an atom, molecule, or ion.
Since the quasi-unique source of information on celestial objects is...
KeywordsRadiation Electromagnetic radiation Radiative transfer Blackbody Free-free Photon
References and Further Reading
- Gary DE (nd) Radio emission mechanisms. http://web.njit.edu/∼gary/728/Lecture2.html
- Goody R, Yung YL (1989) Atmospheric radiation. Oxford University Press, New YorkGoogle Scholar
- Mihalas D (1978) Stellar atmospheres. Freedman, San FranciscoGoogle Scholar
- Rybicki GB, Lightman AP (1979) Radiative process in astrophysics. Wiley, New YorkGoogle Scholar
- Shu FH (1991) The physics of astrophysics 1: radiation. University Science, Mill ValleyGoogle Scholar
- Spitzer L (1978) Physical processes in the interstellar medium. Wiley, New YorkGoogle Scholar