Best Evidence to Date of 'Missing Links' in Black Hole Evolution Uncovered by Experts

A team of researchers may have finally resolved the mystery that is intermediate black holes (IMBHs). For decades, astronomers have been trying to detect these kinds of black holes, with very little success, according to Science Alert. It has now supposedly changed, as experts from Vanderbilt University’s Lunar Labs Initiative (LLI) have revealed that they have found evidence of IMBHs and solved this astronomical enigma. Findings regarding this discovery were detailed in The Astrophysical Journal Letters. 

Experts define intermediate black holes (IMBHs) as black holes whose mass falls somewhere between the masses of stellar-mass black holes and supermassive black holes (SMBHs). The former’s mass is five to 50 times the mass of our sun, while the latter is millions to billions of times more in mass than the sun. Amongst these three kinds of black holes, IMBHs are often labeled as a 'missing' link in black hole evolution, as most of the insights related to them have been theoretical. 

Stellar-mass black holes and supermassive black holes are regularly detected by experts, according to Daily Galaxy. However, evidence associated with IMBHs has been notably absent. Researchers have tried to uncover them, as they are a prominent transitional stage between stellar black holes and SMBHs. The team of researchers associated with this study used data garnered by the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Virgo Collaboration to detect IMBHs.

The analysis detected several gravitational events that had taken place in the universe. Researchers claimed that such events typically occurred during the merging of black holes and produced ripples across spacetime. Further examinations revealed that objects involved in these mergers ranged from 100 to 300 solar masses. This finding was valuable as this is the size range scientists associate with IMBHs. If the assertion is true, then it is the largest black hole collision ever detected by experts. 

Researchers believe that the black holes linked with these gravitational events are the best evidence found to date of IMBHs. Though ecstatic with the findings, researchers still want to further confirm them with readings by the upcoming Laser Interferometer Space Antenna (LISA) mission. The mission slated to launch in the 2030s will have equipment that would monitor these possible IMBHs before they merge. It will give experts more insights into the object’s origin and evolution. 

Another way scientists want to detect IMBHs is by establishing a gravitational wave observatory on the moon. Such an observatory would not be interrupted by Earth’s atmosphere while detecting gravitational waves and cosmic phenomena like black holes. In such circumstances, IMBHs, if present, will be more comprehensible for experts. In 2024, NASA detected a possible IMBH in Omega Centauri. The detection was made based on the fact that there were seven stars in the constellation that should not have been there.

As per estimates, an object was gravitationally pulling these stars. This object could be a black hole in the size range typically associated with an IMBH. "This discovery is the most direct evidence so far of an IMBH in Omega Centauri," Nadine Neumayer, team lead of the Max Planck Institute for Astronomy in Germany, said. "This is exciting because there are only very few other black holes known with a similar mass. The black hole in Omega Centauri may be the best example of an IMBH in our cosmic neighborhood." The team wants to conduct further analysis to confirm the findings.