Science, Maths & Technology
Introduction to active galaxies
...history of astronomy was the discovery of quasars. When first recognised, in 1963, quasars appeared at radio and optical wavelengths as faint, point-like objects with unusual optical emission spectra. The name comes from their alternative designations of 'quasi-stellar radio source' (QSR) or 'quasi-stellar object' (QSO), meaning that they resemble stars in their...