Image of the Day: “Einstein’s Quasar & Ring”



The Einstein Cross is a gravitationally lensed quasar that is quadruply imaged, forming a nearly perfect cross, with the lensing galaxy at its center. The quasar is located about 8 billion light years from Earth, while the lensing galaxy is located at a distance of 400 million light years. Many scientists believe quasars are powered by giant black holes feeding on nearby gas. Gas trapped in the black hole's powerful gravity is compressed and heated to millions of degrees, giving off intense light and/or radio energy. Most quasars lurk in the outer reaches of the cosmos, over a billion light years away, and are therefore distant enough to appear stationary to us.

Einstein's Ring shown below shows a foreground galaxy that acts like a huge gravitational lens, pulling the light from the background object around it, keeping it visible. This object, discovered by Radio Astronomers at England's Jodrell Bank Radio Observatory, then imaged in the near infrared with HST is probably a distant background galaxy lensed by an intermediate distance Elliptical galaxy, shown as the bright image at the center of the ring. The Ring is estimated to be about 10-20 times brighter than the background galaxy would appear without lensing.


Image Credit: L. J. King (U. Manchester), NICMOS, HST, NASA


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