reverbation mapping

reverbation mapping

(ri-ver-bĕ-ray -shŏn) An observational method used to determine the relative distance of the broad-line region from its source of ionization, the central powerhouse of an active galaxy. Variations in the brightness of the nucleus are correlated with fluctuations in the intensity of the broad emission lines, and the inferred time delay reveals the separation of the nucleus and broad line gas.