Astronomers have discovered extraordinarily powerful X-ray jets emerging from two ancient supermassive black holes, with each jet stretching nearly 300,000 light-years—almost three times the diameter of the Milky Way galaxy.
The discovery, revealed on June 9 at the 246th meeting of the American Astronomical Society in Anchorage, Alaska, is being hailed as a major step toward understanding the early universe. The research team, led by Jaya Maithil, a postdoctoral fellow at the Harvard-Smithsonian Centre for Astrophysics, made the discovery using NASA’s Chandra X-ray Observatory and the Karl G. Jansky Very Large Array (VLA).
“These quasars are like cosmic time capsules,” said Dr Maithil, referring to the supermassive black holes powering the jets. “If we understand them, we can understand how they were impacting the growth of their galaxy and the environment in which they resided.”
The black holes are located at distances of roughly 11.6 and 11.7 billion light-years from Earth, which means the jets are being observed as they existed when the universe was only about three billion years old. This was a period of rapid growth for galaxies and the black holes at their centres.
One of the jets, originating from a quasar labelled J1610+1811, can be seen in a Chandra image released with the findings. A faint purple line extends from the quasar's bright white core, suggesting the scale and intensity of the phenomenon. A second, dimmer jet appears to extend in the opposite direction.
Dr Maithil compared the challenge of observing the jets to “looking for candlelight in close vicinity to a flashlight that’s blazing toward us,” noting the difficulty in detecting such faint structures over vast cosmic distances.
What makes the discovery particularly significant is that the jets remain visible across billions of light-years. According to a paper accepted for publication in The Astrophysical Journal, the jets are likely illuminated by interactions with the cosmic microwave background (CMB) radiation — the faint afterglow of the Big Bang.
The study suggests that as the jets travel through space, electrons within them interact with the CMB photons, boosting them to X-ray energies. This phenomenon, known as inverse Compton scattering, allows these ancient jets to remain detectable even now.
“These black holes are transforming the first light of the universe into high-energy jets,” Maithil said, emphasising the role such structures may have played in shaping their host galaxies and surrounding cosmic environments.
