For decades, astronomers have divided black holes into three categories: stellar-mass, supermassive, and intermediate. Stellar-mass black holes are small, with masses 5-50 times that of the Sun, while supermassive ones are massive, with millions to billions of times more mass. Intermediate black holes (IMBHs) fall in between.
Despite numerous observations of stellar-mass and supermassive black holes, IMBHs have been elusive. They’re thought to be a crucial part of black hole evolution, but finding evidence has proven challenging.
A recent study by an international team led by researchers at Vanderbilt University’s Lunar Labs Initiative suggests that they may have found IMBHs. The team reanalyzed data from the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Virgo Collaboration to search for signs of mergers between black holes with masses 100-300 solar masses.
The results indicate that these massive collisions are the largest recorded by astronomers, placing them in the expected range for lightweight IMBHs. According to astronomer Karan Jani, “Black holes are cosmic fossils” and this new population opens a window into the early universe.
Future research, including the Laser Interferometer Space Antenna (LISA) mission, aims to verify these findings. LISA will track black hole collisions for years before they merge, allowing astronomers to study their origin and evolution.
NASA is also exploring the possibility of building a lunar gravitational wave observatory as part of its Artemis program. This would enable scientists to observe IMBHs using space-based detectors on the Moon.
Source: https://www.sciencealert.com/the-universes-missing-black-holes-may-have-been-located