Astronomers find three supermassive black holes in galaxy 1.2 billion years after Big Bang

August 31, 2026 at 02:15 PM2 min

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An international team led by Hannah Übler at the Max Planck Institute for Extraterrestrial Physics has identified three actively feeding supermassive black holes in galaxy J0148-4214, the first such trio found in the distant universe. The galaxy lies at a redshift of 5.0167, about 1.2 billion years after the Big Bang, and its light took 12.5 billion years to reach Earth. The discovery, published in Astronomy & Astrophysics, challenges current models of black hole growth in the early universe.

Key Facts

Galaxy J0148-4214 contains three actively feeding supermassive black holes, the first such trio identified in the distant universe.
The galaxy is at a redshift of 5.0167, about 1.2 billion years after the Big Bang, and its light took 12.5 billion years to reach Earth.
Two of the black holes sit near the galactic centre, roughly 620 light-years apart, while the third is about 5,500 light-years away.
The smallest black hole, with a mass of about 600,000 suns, is feeding faster than the Eddington limit permits.
The galaxy's total stellar mass is about 1.3 billion suns, making the black holes a significant fraction of its mass.

Detection Method

The black holes were identified through a broad smear in the hydrogen emission line H-alpha, caused by gas orbiting at speeds from 430 to 2,920 kilometres per second. The smear appears in hydrogen but not in bright oxygen lines, which come from thinner gas further out that never moves that fast. Spectro-astrometry, which measures tiny shifts in where light appears to come from across a spectral line, was used to separate the two central objects. Without the integral field unit on Webb's NIRSpec instrument, only one of the three black holes would probably have been noticed, according to the Max Planck Society.

Black Hole Properties

The primary black hole has a mass of roughly 80 million suns, its central neighbour about 600,000 suns, and the outlying one about 2 million suns. Giovanni Mazzolari, the study's second author, puts the galaxy's entire stellar mass at about 1.3 billion suns. The smallest black hole is feeding faster than the Eddington limit, the point where radiation from infalling matter should throttle its own food supply. Exceeding the Eddington limit means the standard theory of black hole growth has stopped applying in this case.

Early Universe Implications

Giant black holes appearing so early in cosmic history has been an awkward problem for decades, as steady accretion is too slow to grow them from stellar-mass seeds. Collisions between black holes offer a shortcut to rapid growth, and the presence of three in one galaxy supports this scenario.