Scientists in a neighboring galaxy of the Milky Way have discovered a rare black hole of a variety called dormant black holes, which in theory should be very common but very difficult to find.
The challenge of discovering what astronomers call silent black holes stems from the fact that these objects are not fueled by matter such as gas, dust, or stellar material separated from a companion star. Without surrounding material, these black holes do not emit the X-rays that scientists use to identify ordinary black holes.
Now, according to researchers, the new discovery could help better understand how stars collapse at the end of their lives. slow Tomer Shenar, an astrophysicist at the University of Amsterdam in the Netherlands and the lead author of the new study, which was published on July 18 in the journal Nature Astronomy, said: "We have identified a needle in a haystack. .
He and his colleagues succeeded in discovering a black hole with a stellar mass of about nine times that of the Sun, growing in the Tarantula Nebula, a galactic star-forming region in our neighboring galaxy, the Magellanic Cloud. This black hole revolves around a large blue star with a mass equivalent to 25 times that of the Sun, and the two form a binary system called VFTS 243.
Although it is expected that there are billions of dormant black holes in almost every galaxy. Yes, but this is the first definitive discovery of this type of black hole with a stellar mass outside the Milky Way. But VFTS 243's black hole may be rare for another reason.
Stellar-mass black holes usually form when massive stars run out of fuel to continue nuclear fusion. The end of fusion also ends the outward force that protects the star from collapsing inward due to gravity. Thus, the collapse of the star's core occurs, often accompanied by a massive cosmic explosion called a supernova, which ejects the star's outer layers. There is no such thing as a supernova with a collapsing star.
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Shenar added: The star that formed the black hole in the VFTS 243 system appears to have completely collapsed (collapsed inward), with no signs of a previous explosion. Evidence of this direct collapse scenario is only just being identified, but our study is arguably one of the most direct indications of this.
The Tarantula star forming nebula where this black
hole was discovered.
Credit: ESO, ALMA (ESO/NAOJ/NRAO)/Wong et al., ESO/M.-R. Cioni/VISTA Magellanic Cloud survey. Acknowledgment: Cambridge Astronomical Survey Unit
Black hole police
The discovery of such a black hole by this particular team of scientists may come as a surprise to the astronomical community, as this team usually looks for possible black holes rather than the existence of them. Confirm them. These explorations have made Kareem El-Badry of the Harvard and Smithsonian Center for Astrophysics to call them the "black hole police". Check again, I hesitated. But I couldn't find a plausible explanation that the data didn't involve a black hole.
The discovery of VFTS 243 required a careful review of six years of data collected by the Very Large Telescope (VLT), located in the Atacama Desert in northern Chile. . In this data, the scientists examined 1,000 massive stars in the Tarantula Nebula region of the Large Magellanic Cloud to find out which could have a dormant black hole companion.
The research team analyzed the spectrum of each star at different wavelengths. and thus in the VFTS 243 data, he detected strange points in the star's orbit that could have been created by a compact but massive companion." I expect others in the field to scrutinize our analysis and try to propose alternative models for it.
Cover photo: A graphic representation of a black hole and a hot blue star in a binary system. Credit: ESO/L. Calada