The light from quasar J0439+1634, some 12.8 billion light years away, passes close to a faint galaxy that is about six billion light years away. The gravity of this foreground galaxy warps the space around it, according to Einstein’s theory of general relativity. This bends the light like an optical lens, magnifies the quasar image by a factor of fifty, while at the same time split the quasar image into three. Both the foreground galaxy and the multiply imaged quasar are captured by the high resolution image of the Hubble SpaceTelescope. Credit: NASA, ESA, Xiaohui Fan (University of Arizona)
Observations from Gemini Observatory identify a key fingerprint of an extremely distant quasar, allowing astronomers to sample light emitted from the dawn of time. Astronomers happened upon this deep glimpse into space and time thanks to an unremarkable foreground galaxy acting as a gravitational lens, which magnified the quasar’s ancient light. The Gemini observations provide critical pieces of the puzzle in confirming this object as the brightest appearing quasar so early in the history of the Universe, raising hopes that more sources like this will be found.
Before the cosmos reached its billionth birthday, some of the very first cosmic light began a long journey through the expanding Universe. One particular beam of light, from an energetic source called a quasar, serendipitously passed near an intervening galaxy, whose gravity bent and magnified the quasar’s light and refocused it in our direction, allowing telescopes like Gemini North to probe the quasar in great detail.