Scientists using NASA’s Chandra X-ray Observatory have detected a jet emitted by a supermassive black hole so ancient and distant that it is illuminated by cosmic microwave background radiation leftover from the Big Bang.
Coming from the black hole system known as B3 0727+409, the jet stretches as long as 300,000 light years. Its light was emitted when the universe was just 2.7 billion years old, a time when cosmic microwave background radiation was much more intense than it is today.
Jets emitted by black holes are usually detected by radio observatories because their electrons’ most powerful emissions are in the radio wavelengths.
However, no radio signals have been detected from B3 0727+409. Instead, the system is easily detected in X-ray images.
These x-rays were discovered incidentally when they appeared in Chandra’s field of view while researchers were looking for something else entirely, said Lukasz Stawarz of Poland’s Jagiellonian University, a co-author of this study.
The jet produced by B3 0727+409 is brightened in X-ray wavelengths when its electrons, which depart the black hole traveling at light speed, move through cosmic microwave background radiation and collide with microwave photons.
That collision boosts the photons’ energy into X-ray wavelengths.
“Because we’re seeing this jet when the universe was less than three billion years old, the jet is about 150 times brighter in X-rays than it would be in the nearby universe, ” explained Aurora Simionescu of the JAXA Institute of Space and Astronautical Studies (ISAS) and study leader.
Researchers estimate electrons in the jet have been traveling very close to light speed over hundreds of thousands of light years.
So far, few black hole jets remote enough to be brightened by the cosmic microwave background radiation have been detected.
This new finding, published in the January 2016 issue of The Astrophysical Journal Letters, suggests black holes with powerful jets may be more abundant in the early universe that scientists suspected.
Long jets emitted by nearby black holes have been seen, but scientists are unsure about how they give off X-rays.
Study co-author Teddy Cheung of the Naval Research Laboratory in Washington, DC, noted activity in early supermassive black holes may be different from that in the early universe.
“By finding and studying more of these distant jets, we can start to grasp how the properties of supermassive black holes might change over billions of years,” he said.