The discovery of this superwalled black hole was made possible by the newly identified tidal disruption event, AT2024TVD.
Tidal Disruption Event AT2024TVD. Image credits: NASA/CXC/University of California, Berkeley/Yao et al. /ESA /STSCI /HST /J. DEPASQUALE.
“A tidal disruption event (TDE) occurs when stars are either stretched or ‘spaghettified’ by the immense gravitational forces of black holes,” explained UC Berkeley researcher Dr. Yuhanyao.
“The remnants of the torn-apart stars are pulled into a circular orbit around the black hole.”
“This process creates high-temperature shocks and emissions that can be detected in ultraviolet and visible light.”
The AT2024TVD event enabled astronomers to utilize the NASA/ESA Hubble Space Telescope to identify elusive wandering supermassive black holes, supported by observations from NASA’s Chandra X-ray Observatory.
Interestingly, these 1 million rogue black holes are often found to be supermassive and actively consuming surrounding material.
Among the roughly 100 TDEs recorded by the Light Sky Survey, this marks the first instance of an offset TDE being identified.
In fact, at the center of the host galaxy lie ultra-massive black holes differing in mass by 100 million solar masses.
Hubble’s optical precision indicates that the TDE is located just 2,600 light-years from the larger black holes at the galaxy’s core.
This distance is comparable to just one minute of the span between our Sun and the central ultra-massive black hole of the Milky Way.
The larger black hole expels energy as it accumulates material, classifying it as an active galactic nucleus.
Interestingly, the two supermassive black holes exist within the same galaxy but are not gravitationally linked like a binary pair.
Smaller black holes can potentially spiral toward the center of the galaxy, eventually merging with their larger counterparts.
However, at this point, they are too distant to be bound by gravity.
“AT2024TVD is the first offset TDE captured through optical observations, opening up new possibilities for studying this elusive population of black holes in future surveys,” Dr. Yao remarked.
“Currently, theorists have not focused extensively on offset TDEs.
“I believe this discovery will drive scientists to search for more instances of this type of event.”
The black holes responsible for AT2024TVD are traversing the bulges of gigantic galaxies.
Black holes periodically consume stars every tens of thousands of years, lying dormant until their next “meal” arrives.
How did the black hole become displaced from the center? Previous studies suggest that three-body interactions can eject lower-mass black holes from a galaxy’s core.
This theory may apply here, given its proximity to the central black hole.
“If a black hole undergoes a three-body interaction with two other black holes in the galaxy’s core, it can remain bound to the galaxy and orbit the central region,” explained Dr. Yao.
Another possibility is that these black holes are remnants from a smaller galaxy that merged with the host galaxy over a billion years ago.
In such a case, the black hole could eventually merge with the central active black hole in the distant future. As of now, astronomers remain uncertain about its trajectory.
“There is already substantial evidence that the galaxy will increase its TDE rate, but the presence of a second black hole associated with AT2024TVD suggests a past merger has occurred.”
The team’s survey results will be published in the Astrophysical Journal Letters.
____
Yuhan Yao et al. 2025. A massive black hole located 0.8 kpc from the host nucleus. apjl in press; Arxiv: 2502.17661
Source: www.sci.news
