They detect an intermediate mass black hole with a gravitational lens

Australian researchers have detected, thanks to a gravitational lens, a black hole of about 55,000 solar masses, a kind of body whose formation process has yet to be explained, according to a study published in the journal “Nature Astronomy”.

Scientists know the mechanisms that lead to the appearance of small black holes from the collapse of stars, as well as those of the supermassive holes that reside in the center of galaxies, but it has not yet been described in detail how the elusive ones are formed. intermediate mass holes.

The LIGO gravitational wave detector first identified such a body last September, but direct evidence of its existence remains “scant and inconclusive,” according to the scientific publication.

Astronomers are now trying to gather more observations of intermediate-mass holes to estimate how many may exist in the universe and infer what their formation process is.

With this objective, a group of researchers from the University of Melbourne analyzed thousands of gamma ray bursts, the luminous explosions that occur after the collapse of a star or the collision of two of them.

Among those data, they looked for signs of gravitational lensing, a phenomenon that occurs when a high-mass object gets in the path of light and deflects its path, allowing them to identify bodies that would otherwise remain hidden.

One of the bursts showed a distortion, caused, the researchers have concluded, by an object of tens of thousands of solar masses that they consider a good candidate to be an intermediate black hole.

“This newly discovered black hole could be an ancient relic, a primordial hole created in the early universe, before the first stars and galaxies appeared,” said Eric Thrane, one of the authors of the work, in a statement from his university.

“These early black holes could be the seeds of the supermassives that today live in the center of galaxies,” he added.