The source of the 160,000-light-year-long jet of particles is PSO J352.4034-15.3373 (PJ352-15 for short), a rapidly growing supermassive black hole, or quasar, located about 12.7 billion light-years away in the constellation of Aquarius.
An artist’s illustration of a close-up view of a quasar and its jet, like the one in PJ352-52. Image credit: NASA / CXC / M. Weiss.
“Around supermassive black holes, we think jets can take enough energy away so material can fall inward and the black hole can grow,” said Dr. Thomas Connor, an astronomer at NASA’s Jet Propulsion Laboratory.
Dr. Connor and colleagues needed to observe PJ352-15 for a total of three days using the sharp vision of NASA’s Chandra X-ray Observatory to detect evidence for the X-ray jet.
X-ray emission was detected about 160,000 light-years away from the quasar along the same direction as much shorter jets previously seen in radio waves by the Very Long Baseline Array.
PJ352-15 breaks a couple of different astronomical records.
First, the longest jet previously observed from the first billion years after the Big Bang was only about 5,000 light-years in length, corresponding to the radio observations of PJ352-15.
Second, PJ352-15 is about 300 million light-years farther away than the most distant X-ray jet recorded before it.
“The length of this jet is significant because it means that the supermassive black hole powering it has been growing for a considerable period of time,” said Dr. Eduardo Bañados, an astronomer at the Max Planck Institute for Astronomy.
“This result underscores how X-ray studies of distant quasars provide a critical way to study the growth of the most distant supermassive black holes.”
This image shows X-ray data from Chandra of PJ352-15, along with optical and infrared data from the Gemini-North telescope and the Keck I telescope, respectively. Image credit: NASA / CXO / JPL / T. Connor / Gemini / NOIRLab / NSF / AURA / W.M. Keck Observatory.
The light detected from this jet was emitted when the Universe was only 0.98 billion years old, less than a tenth of its present age.
At this point, the intensity of the Cosmic Microwave Background radiation left over from the Big Bang was much greater than it is today.
As the electrons in the jet fly away from the black hole at close to the speed of light, they move through and collide with photons making up the cosmic microwave background radiation, boosting the energy of the photons up into the X-ray range to be detected by Chandra.
In this scenario, the X-rays are significantly boosted in brightness compared to radio waves.
This agrees with the observation that the large X-ray jet feature has no associated radio emission.
“Our result shows that X-ray observations can be one of the best ways to study quasars with jets in the early Universe,” said Dr. Daniel Stern, an astronomer at NASA’s Jet Propulsion Laboratory.
“Or to put it another way, X-ray observations in the future may be the key to unlocking the secrets of our cosmic past.”
Thomas Connor et al. 2021. Enhanced X-ray Emission from the Most Radio-Powerful Quasar in the Universe’s First Billion Years. ApJ, in press; arXiv: 2103.03879