As many as 2,000 black holes kicked away from their homes are now living on the outskirts of our Milky Way galaxy, according to a new study.
Researchers from the University of California, Santa Cruz, used new computer simulations to look at how our galaxy grew through mergers with smaller galaxies.
Scientists believe that every galaxy may have a black hole at its centre. As galaxies merge, their central black holes merge too, building a super massive black hole millions of times the mass of the Sun.
But collisions between black holes create gravitational waves, which can kick a newly merged black hole out of its host galaxy, New Scientist reported.
Valery Rashkov and Piero Madau of the University of California, ran simulations that show 70 to 2,000 of these outcasts may now linger in the halo of the Milky Way, depending on the properties of the objects that collided.
Some might have been stripped bare, while others may carry a few clusters of stars and dark matter, said Avi Loeb of Harvard University, who has proposed a similar idea.
Though faint, these star clusters should be observable with current or future telescopes.