GW190521, as the colossal event has been named, is the most massive black hole collision we've ever directly detected. The instruments on May 21 a year ago were triggered by a strong signal that lasted just for one-tenth of a second.
Both black holes combined when the Universe was just roughly seven billion years old, which is approximately 50% of its current age.
The result of the merger created an even more massive black hole, of about 142 solar masses.
Then, there is this new intermediate black hole, which is in between the two.
The gravitational waves were traced on Earth on May 21, 2019, by the dual detectors of the National Science Foundation's Laser Interferometer Gravitational-wave Observatory in the United States, as well as the Virgo gravitational-wave detector in Italy. The most recent detection is the farthest merger that LIGO and Virgo have ever found.
R. Abbott et al (LIGO Scientific Collaboration and Virgo Collaboration).
Findings on the discovery were published in Physical Review Letters.
"The mass of the larger black hole in the pair puts it into the range where it's unexpected from regular astrophysics processes", said Peter Shawhan, a physics professor at the University of Maryland.
"This is of tremendous importance since it showcases the instrument's ability to detect signals from completely unforeseen astrophysical events".
When the two black holes collided a massive burst of energy was released. Other black holes, called "supermassive", are unfathomably large, amounting to billions of times the mass of the sun, such as Sagittarius A*, at the center of the Milky Way.
Alberta employment stagnant as people exit the workforce: Statistics Canada
Despite the challenging outlook, Donald Trump hailed Friday's report and latest unemployment rate as "much better than expected". Democratic nominee Joe Biden downplayed the report and said the viral outbreak is still weighing on the economy .
Now to the final 142 solar-mass black hole.
The other common path by which black hole mergers form is via dynamical interactions.
Stellar-class black holes are typically created when a large star runs out of its nuclear fuel and the churning engine of light and heat stops. Galaxies are often surrounded by dense clumps of stars called globular clusters. But in the very biggest stars, the collapse is even more catastrophic, causing a runaway thermonuclear explosion that destroys the star and leaves nothing behind.
The researchers suggest that the 85-solar-mass black hole was not the product of a collapsing star, but was itself the result of a previous merger. Puzzlingly, however, the two black holes that merged are heavier than expected: their masses fall in a gap in which theorists believe it is impossible to make a black hole via the usual route of a collapsing star.
"This event opens more questions than it provides answers", said Alan Weinstein, LIGO member and a professor of physics at the California Institute of Technology, in a statement. We are very excited to have achieved the first direct observation of an IMBH in this mass range.
But LIGO's most recent discovery, which has been labeled GW190521, stands out from the crowd. Scientists with the LIGO and VIRGO Scientific Collaboration report spotting an IMBH billions of light-years away thanks to peculiar gravitational waves. The paper accompanying the discovery also discusses alternate scenarios - including elliptical orbits, head-on collision of the black holes, core-collapse supernovae, etc.
However, scientists have caught another unusual feature of GW190521: a clear gravitational signal was identified using algorithms that carry out a general search for sources of gravitational waves.
"Up to now we knew of two populations of black holes", Berry said. It also released a huge "bang" of leftover energy, equivalent to about eight solar masses, in the form of gravitational waves able to be detected on Earth. But he assured that they were produced so far from the Solar System that we could never detect them. Astrophysicists often estimate the size of the object from the properties of gravitational waves. "The signal also could be from a cosmic string produced just after the universe inflated in its earliest moments - although neither of these exotic possibilities matches the data as well as a binary merger".
So this is the first ever observation of a black hole in a range between stellar mass and supermassive black holes.
The possibility of the hierarchical merger, where each black hole in this merger likely formed from the merger of two smaller black holes, is included by the researchers in the second study.
"No matter what we do, we can not easily produce this event in these more common formation channels", Vitale says.