Scientists are already aware of the supermassive black hole at the center of the Milky Way, and now they have discovered thousands more black holes surrounding it. Scientists have speculated that black holes tend to sink to the center of the galaxy and now they may have found proof.
The newly discovered black holes are within about 30.9 trillion kilometres of the supermassive black hole at the centre.
"In a sense, this is the only laboratory we have to study this phenomenon". Throughout the MIlky Way, scientists have only been able to find five dozen black holes.
The galactic centre is already known to teem with stars, supernovae, pulsars, gas and dust, and the very large black hole called Sagittarius A*, whose mass is equivalent to four million suns.
This supports the hypothesis that the massive halo of gas and dust around Sagittarius A* has produced many massive stars that have lived, died and collapsed into black holes. But estimated that there could be up to 20,000 of them extending further out from Sagittarius A* based on calculations.
Some of these bind - or "mate" - to passing stars, forming binary systems.
Known as Sagittarius A (Sgr A), the supermassive black hole at the heart of our galaxy is surrounded by a halo of gas and dust - believed to be the ideal breeding ground for huge stars that collapse into black holes when they die. The takeout shows the 12 black holes scientists spotted are actually black hole binaries, with the gas of a nearby star being transferred into the disk around the black hole as it moves toward the centre.
First, she says, because "there are large clusters of hot, massive stars towards the centre of our galaxy and these stars become black holes at the end of their lives".
Astronomers have previously looked for black holes that are gravitationally bound to a companion star, which can provide fuel for very bright X-ray outbursts - but such eruptions are rare.
"It would be so easy if black hole binaries routinely gave off big bursts like neutron star binaries do, but they don't, so we had to come up with another way to look for them", Hailey said.
But binary black hole systems are likely only 5 per cent of all black holes, so that means there are really thousands of them, Hailey said.
To find the black holes, the team had to think outside the box.
"But when black holes mate with a low mass star, the marriage emits X-ray bursts that are weaker, but consistent and detectable".
But the scientists have admitted the estimates are much graver, with as many as 20,000 black hole out there in the vast depths of deep space.
The team observed the X-ray signatures of 12 black hole binaries within three light years of Sagittarius A. From this data, they extrapolated that there must be several hundred more paired black holes and about 10,000 isolated ones, NPR reported.
"This finding confirms a major theory and the implications are many", said Hailey. "It is going to significantly advance gravitational wave research because knowing the number of black holes in the center of a typical galaxy can help in better predicting how many gravitational wave events may be associated with them". This area of the universe has been the focus of the Cosmic Evolution Survey (COSMOS), which probes for signs of galaxy formation and evolution as a function of cosmic time and the local galaxy environment.
The research was funded by NASA.