This figure shows the standard quasar-galaxy gravitational lens, where a foreground galaxy magnifies a background quasar. The light from the quasar is redirected by the foreground galaxy to create two images of the quasar. In the new “reverse” quasar-galaxy gravitational lens, the quasar sits at the center of the lens system and its gravity creates two or more images of the massive background galaxy.
© NASA

This figure shows the standard quasar-galaxy gravitational lens, where a foreground galaxy magnifies a background quasar. The light from the quasar is redirected by the foreground galaxy to create two images of the quasar. In the new “reverse” quasar-galaxy gravitational lens, the quasar sits at the center of the lens system and its gravity creates two or more images of the massive background galaxy.

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