Australian astronomers have presented evidence for the existence of intermediate mass black holes. The first object that can be confidently attributed to this class was recorded by them as a result of the analysis of gravitational lensing of gamma-ray bursts. The results of the study are published in the journal Nature Astronomy.
Astronomers have long sought to find an intermediate-mass black hole - the long-awaited "missing link" between supermassive black holes many millions of times heavier than the Sun in galactic cores and stellar mass black holes that form after a single massive star collapses or two stars merge. Until recently, the very existence of such black holes was questioned and hotly discussed in the scientific community.
Researchers at the University of Melbourne and Monash University have reported that they have discovered the first legendary "intermediate" black hole with a mass about 55 thousand times the mass of the Sun. The effect of the distortion of light from an explosion that occurred in the early Universe helped to identify it.
The authors analyzed thousands of bursts of gamma rays from collapsing or merging stars to look for signs of gravitational lensing, which occurs when an object acting as a lens is in the path of gamma waves. In this case, it is a black hole.
This is the only way to detect the presence of dark objects in the path of gamma waves that would otherwise remain invisible. When waves bend around such an object, the radiation of distant explosions is distorted, and from the delay time of the waves - a kind of "echo" - you can calculate the mass of the obstacle object.
Powerful software, specially designed to detect black holes using gravitational waves, has confirmed that two gamma-ray bursts, detected with a certain delay, are evidence of an intermediate mass black hole.
According to the researchers, this discovery is critical to understanding how black holes form and grow over time, and how low-mass black holes become supermassive "monsters" located in the centers of galaxies.
"While we know that supermassive black holes lurk in the cores of most, if not all galaxies, we do not yet understand how these monsters grew so large," the first author of the article, graduate student James Paynter, said in a press release from the University of Melbourne.).
"This newly discovered black hole may be an ancient relic, the primordial black hole that formed in the early universe before the first stars and galaxies were formed," continues study leader Professor Eric Train of the Monash University School of Physics and Astronomy, Principal Investigator of the Center of Excellence for the discovery of gravitational waves (OzGrav) of the Australian Research Council. "Such early intermediate-mass black holes could be the seeds of the supermassive black holes that live in the hearts of galaxies today."
The authors believe that now it will be easier for them to find other similar objects and estimate their total number in the Universe. According to researchers, only in the vicinity of our Galaxy there should be about 46 thousand black holes of intermediate mass.