Lensing explained
Date: 07 April 2021
Satellite: Gaia
Copyright: R. Hurt (IPAC/Caltech)/The GraL Collaboration
This diagram illustrates how quadruply-imaged quasars, or quads for short, are produced on the sky. The light of a distant quasar, lying billions of light-years away, is bent by the gravity of a massive galaxy that happens to sit in front of it, as seen from our point of view on Earth. The bending of the light results in the illusion that the quasar has split into four similar objects surrounding the foreground galaxy.
Last Update: 7 April 2021