Astronomers using archival data from the Gemini North telescope have measured a binary supermassive black hole located within the elliptical galaxy B2 0402+379.
The pair of compact objects in the center of B2 0402+379 is the only supermassive black hole binary ever resolved in enough detail to see both objects separately.
It holds the record for having the smallest separation ever directly measured — a mere 24 light-years.
While this close separation foretells a powerful merger, further study revealed that the pair has been stalled at this distance for over 3 billion years, begging the question; what’s the hold-up?
To better understand the dynamics of the system and its halted merger, Stanford University’s Professor Roger Romani and his colleagues looked to archival data from Gemini North’s Gemini Multi-Object Spectrograph (GMOS), which allowed them to determine the speed of the stars within the vicinity of the black holes.
“The excellent sensitivity of GMOS allowed us to map the stars’ increasing velocities as one looks closer to the galaxy’s center. With that, we were able to infer the total mass of the black holes residing there,” Professor Romani said.
The authors estimate the binary’s mass to be a whopping 28 billion times that of the Sun, qualifying the pair as the heaviest binary black hole ever measured.
Not only does this measurement give valuable context to the formation of the binary system and the history of its host galaxy, but it supports the long-standing theory that the mass of a supermassive binary black hole plays a key role in stalling a potential merger.
“The data archive serving the International Gemini Observatory holds a gold mine of untapped scientific discovery,” said Dr. Martin Still, NSF program director for the International Gemini Observatory.
“Mass measurements for this extreme supermassive binary black hole are an awe-inspiring example of the potential impact from new research that explores that rich…
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