Fig12_13 Galaxy cluster lens

Fig12_13 Galaxy cluster lens

Fig. 12.13 . Very distant and faint galaxies can be investigated by observing them through a cluster of galaxies. The powerful gravitation of the cluster acts like a lens, bending, focusing and magnifying the light of more distant galaxies that lie behind it (see Fig. 12.14). The gravitational lens action can distort the light from the background galaxies into faint arcs, or produce magnified images of individual galaxies that would otherwise remain invisible. (Courtesy of NASA/JPL-Caltech.)

Copyright 2010, Professor Kenneth R. Lang, Tufts University