Astronomers have made a groundbreaking discovery about a distant supermassive black hole in the quasar RX J1131, located about 6 billion light-years from Earth. This black hole has a corona, a hot cloud of gas that gives off intense energy as it pulls in nearby materials.
Using the Atacama Large Millimeter/submillimeter Array (ALMA) telescope in Chile, researchers observed how the black hole’s light changed over the years. These small changes helped them learn about the size and brightness of the gas surrounding the black hole.
The work was led by Matus Rybak from Leiden University, who studies the hot gases and magnetic fields around active black holes. The corona around RX J1131 is extremely hot, measuring millions of degrees. This heating causes the gas to shine in high-energy X-rays and lower-energy radio waves.
The setup is fascinating. A galaxy between us and RX J1131 causes gravitational lensing, bending the light from the quasar. This effect splits the light into four different images. Each image takes a unique path through space, and individual stars in the lensing galaxy can briefly magnify parts of the quasar’s light, a phenomenon called microlensing.
Thanks to this unusual alignment, scientists gained a clearer view of the corona, a feat impossible with most telescopes. Rybak’s team analyzed past and recent data and discovered that the brightness changes indicated the light was coming from a small area near the black hole. They estimated that this emitting zone spans about 50 astronomical units—about the distance from the Sun to the outer part of our solar system.
These findings suggest that the corona’s size is compact and shaped by powerful magnetic fields. Earlier theories hinted that emissions in radio-quiet quasars like RX J1131 might come from regions closer to the black hole, rather than from star-forming areas. The correlation between radio and X-ray outputs in this quasar supports this idea.
Moreover, monitoring RX J1131 has changed recent views on how stable the radiation from these quasars can be. Researchers now observe variations in X-rays and millimeter waves, indicating dynamic behaviors near the black hole’s corona.
Looking ahead, ALMA is set to explore lower radio frequencies, where black hole coronas shine the brightest. This expansion will help astronomers find more distant quasars and explore their environments.
The findings were published in Astronomy & Astrophysics and open the door to new discoveries about black holes and their surrounding regions. As tools improve and new telescopes like the Vera C. Rubin Observatory come online, we’re likely to uncover thousands of examples similar to RX J1131, enriching our understanding of the universe.
For further insights, you can read more on the ALMA website or check out the Chandra X-ray Observatory’s observations.
