An international team of astronomers, known as the “the black hole police” for his work disproving the discoveries of these space elements, he discovered a new stellar-mass black hole in the Large Magellanic Clouda neighboring galaxy to the Milky Way.
The lead author of the study published today by Nature Astronomy, Tomer Shenarpoints out that this is the first time that this team “comes together to publicize the discovery of a black hole, instead of to refute it”.
“We identified a needle in a haystack”says Shenar, who began the study at the KU Leuven center in Belgium and now has a Marie Curie fellowship at the University of Amsterdam in the Netherlands.
Although other similar candidates for black holes have been proposed, the science team says this is the first “dormant” stellar-mass black hole to be unequivocally detected outside our galaxy.
Stellar-mass black holes form when massive stars reach the end of their life and collapse under their own gravity.
In a binary system, consisting of two stars rotating around each other, this process leaves a black hole orbiting with a bright companion star.
The black hole is “dormant” if it does not emit high levels of X-rays.this is how these spatial elements are usually detected.
“It’s amazing that we barely know about these dormant black holes, given how common the scientific community assumes they are,” says co-author Pablo Marchant of KU Leuven.
The newly discovered black hole is at least nine times the mass of our Sun and orbits a hot blue star that weighs twenty-five times the mass of the Sun.
Dormant black holes are particularly difficult to detect because they interact little with their environment.
“For more than two years, we were looking for this type of binary black hole systems“, says co-author Julia Bodensteiner, a researcher at the European Southern Observatory (ESO) in Germany.
To find this black hole, dubbed VFTS 243, the team probed nearly a thousand massive stars in the Tarantula Nebula region of the Large Magellanic Cloud, looking for any that might have companions. black hole.
Identifying these companions as black holes is extremely difficult, as there are many alternative possibilities.
“As a researcher who has disproven possible black holes for the past few years, I was extremely skeptical of this finding,” admits Shenar.
This skepticism was shared by the co-author Kareem El Badry, from the Harvard & Smithsonian Center for Astrophysics, in the United States, which Shenar calls “the destroyer of black holes”.
“When Tomer asked me to review his findings, I had my doubts. But I couldn’t find a plausible explanation for the data that didn’t implicate a black hole,” says El-Badry.
The discovery also offers the team a unique insight into the processes that accompany the formation of black holes.
The astronomical community believes that a stellar-mass black hole forms when the core of a dying massive star collapses, but whether or not this process is accompanied by a powerful supernova explosion is unknown.
“The star that formed the black hole in VFTS 243 seems to have completely collapsedwithout any sign of a previous explosion,” Shenar explains.
“Evidence for this direct collapse scenario has only recently emerged, but our study provides arguably one of the clearest indications. This has huge implications for the origin of black hole mergers in the cosmos. ”