what is happening here: the light from a single quasar is being bent to create four images from the point of view of Earth- bound observers.
Second, this image supports the prevailing theory about the distance of quasars. The name ΓÇ£quasarΓÇ¥ comes from ΓÇ£quasi-stellar objectsΓÇ¥; these objects received this name because they appeared to be like stars but had very different spectral features, including a number of emission lines that could not, at first, be identified. Eventually, it was recognized that the spectral lines were actually well-known lines of hydrogen Doppler shifted to the red end of the spectrum. Such great Doppler shift displacement implied that quasars were moving away from
