Bowen fluorescence mechanism
sâzokâr-e fluoresti-ye Bowen
Fr.: mécanisme de fluorescence de Bowen
A mechanism, made possible by certain chance coincidences between → spectral lines of He II, O III and N III in some → planetary nebulae , that explains the presence with a high intensity of a selected group of O III and N III lines while all other lines of these elements are missing.
A type of → luminescence in which photons of lower energy are emitted as the result of absorption of energy by an atom or molecule from other radiation. The phenomenon lasts as long as the stimulus responsible for it is present.
Coined by English mathematician and physicist Sir George G. Stokes (1819-1903) from fluor-, from → fluorspar, + → -escence, a suffix of nouns denoting action or process, change, state or condition, etc.