RACS J0320-35 Quasar Growing Faster Than Expected, Chandra Reveals

The RACS J0320-35 quasar is one of the fastest-growing black holes ever recorded. NASA’s Chandra X-ray Observatory has revealed that it is expanding at a rate 2.4 times faster than the Eddington limit. This challenges current theories about how supermassive black holes formed in the early universe.

A Billion-Solar-Mass Giant

Weighing about one billion Suns, the RACS J0320-35 quasar lies 12.8 billion light‑years from Earth. Astronomers are seeing it as it was only 920 million years after the Big Bang. It emits more X‑rays than any other black hole known from the universe’s first billion years.

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This quasar’s brilliance comes from huge amounts of matter spiraling inward. As the material falls in, it heats up and produces intense radiation across the spectrum. Normally, radiation pressure limits growth — the Eddington limit — but this object is exceeding that threshold.

Breaking the Rules of Growth

Chandra’s 2023 data show the RACS J0320-35 quasar is gaining between 300 and 3,000 solar masses per year. This suggests it may have started with a smaller mass, possibly under 100 Suns, formed by the collapse of a massive star. Its rapid growth could also explain the rare jets of particles blasting from it at near‑light speed.

Discovery and Observations

First spotted in a radio survey with the Australian Square Kilometre Array Pathfinder, it was later confirmed with optical data from the Dark Energy Camera and distance measurements from the Gemini South Telescope.

A paper on these findings has been accepted by The Astrophysical Journal. NASA’s Marshall Space Flight Center manages Chandra, while the Smithsonian Astrophysical Observatory operates its science and flight control.