Utah [US]: A study published in ‘The Astrophysical Journal’ revealed that astronomers have discovered a black hole which is entirely different in its making, from all other black holes that have been discovered till now.
The newly discovered back hole is smaller than the black holes found at the centre of galaxies, but bigger than the black holes that are born when stars explode. The mass of the black hole has been reported to be one hundred thousand solar masses.
“We have very good detections of the biggest, stellar-mass black holes up to 100 times the size of our sun, and supermassive black holes at the centre of galaxies that are millions of times the size of our sun, but there aren’t any measurements of black holes between these two. There’s a large gap. This discovery fills that gap,” said senior Author Anil Seth, Associate Professor of Astronomy at the University of Utah and co-author of the study.
The black hole was hidden within B023-G078, an enormous star cluster in the Andromeda galaxy.
The researchers used the object’s mass distribution to predict how fast the stars should be moving at a given location within the cluster.
“The stellar velocities we are getting, gives us direct evidence that there’s some kind of dark mass right at the centre,” said lead author Renuka Pechetti of Liverpool John Moores University, who started the research while was at the University of Utah. “It’s very hard for globular clusters to form big black holes. But if it’s a stripped nucleus, then there must already be a black hole present, left as a remnant from the smaller galaxy that fell into the larger one,” she added.
“We know big galaxies form generally from the merging of smaller galaxies, but these stripped nuclei allow us to decipher the details of those past interactions,” said Seth.