Astronomers using NASA's Chandra X-ray Observatory have uncovered a black hole exhibiting one of the fastest growth rates ever recorded. This colossal black hole, located a staggering 12.8 billion light-years from Earth, presents a significant challenge to our understanding of early universe cosmology. Its immense size – approximately a billion times the mass of our Sun – and its position, observable just 920 million years after the Big Bang, make it an exceptional find.
This rapidly expanding black hole powers a quasar, RACS J0320-35, an extraordinarily luminous object that outshines entire galaxies. This intense brightness is fueled by the massive influx of matter spiraling into the black hole's gravitational pull. While initially discovered two years prior, recent Chandra observations from 2023 revealed the quasar's truly remarkable characteristic: its growth rate surpasses the theoretical Eddington limit, a constraint based on the balance between radiation pressure and gravity.
Luca Ighina of the Center for Astrophysics | Harvard & Smithsonian, lead author of the study, described the discovery as "shocking." The intense radiation produced as matter falls into a black hole normally creates pressure that counteracts gravity, limiting the rate of accretion. However, RACS J0320-35 appears to violate this limit, exceeding it by a factor of 2.4.
This superlative growth rate raises questions about the black hole's origins. Slower-growing black holes, according to current theories, require an exceptionally high initial mass – around 10,000 solar masses – to reach a billion solar masses within a billion years. However, RACS J0320-35's rapid growth suggests it may have started with a far smaller mass, perhaps less than a hundred solar masses, growing from a stellar implosion. This challenges existing models of black hole formation and offers valuable insights into the processes shaping the early universe.
The researchers determined the black hole’s growth rate (between 300 and 3,000 solar masses per year) by comparing theoretical models with the detailed X-ray spectrum obtained by Chandra, confirming its super-Eddington growth. Optical and infrared data further support this interpretation. The discovery also sheds light on another astrophysical mystery: the formation of powerful jets emanating from some black holes, which are rare in quasars and may be linked to their exceptional growth rate.
This groundbreaking research, accepted for publication in *The Astrophysical Journal*, utilizes data from multiple sources, including the Australian Square Kilometer Array Pathfinder, the Dark Energy Camera, and the Gemini-South Telescope. The study provides a crucial piece of the puzzle in understanding the formation of the universe's first generation of black holes, pushing the boundaries of our current understanding of astrophysical processes and black hole evolution.
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Originally published at: https://www.nasa.gov/missions/chandra/nasas-chandra-finds-black-hole-with-tremendous-growth/
