Astronomers have uncovered a rogue black hole speeding through a distant dwarf galaxy, challenging long-held assumptions about black hole behavior.
This black hole is not a supermassive one fixed at the galactic core but rather an intermediate-mass black hole wandering with its active region.
The discovery is significant because it proves that black hole growth is not limited to galactic centers. It also sheds light on how supermassive black holes grew rapidly in the early universe.
The off-center accreting black hole resides in the dwarf galaxy MaNGA 12772-12704, about 230 million light-years away. Positioned 3,260 light-years from the center, it emits jets as it travels.
“This is like a cosmic lighthouse lit by a wandering black hole,” said Shanghai Astronomical Observatory astronomer Liu Yuanqi. Despite drifting, it radiates immense energy.
Traditionally, galaxies are thought to house supermassive black holes at their cores, fueling active galactic nuclei. Yet evidence grows that some massive black holes drift into disks or outskirts.
Wandering black holes are best hunted in dwarf galaxies, whose simpler structures preserve more clues about early cosmic history. Mergers or gravitational recoil can dislodge black holes from galactic centers.
Using MaNGA survey data, astronomers detected weak AGN activity at the center of MaNGA 12772-12704. Surprisingly, strong radio emissions were found offset 3,000 light-years away.
Follow-up observations with the Very Long Baseline Array revealed temperatures above 1.8 billion degrees Fahrenheit and a 7.2 light-year-long jet. These signatures resemble central AGNs.
Archival data from 1993 to 2023 showed the region brightening and dimming over decades, a sign of ongoing accretion. The black hole’s mass is around 300,000 suns, classifying it as an intermediate-mass black hole.
Such black holes are considered missing links between stellar-mass and supermassive black holes. This finding confirms they can feed and generate jets even away from galactic centers.
The study suggests black holes can grow “offsite,” explaining how early supermassive black holes expanded to immense sizes within the universe’s first billion years.
“This discovery prompts us to rethink black hole–galaxy co-evolution,” said team leader An Tao. “Black holes may also reshape galaxies quietly from the outskirts.”
