The second largest black hole in the Milky Way galaxy – which was discovered by a team of Japanese astronomers – located two hundred light-years from the galaxy’s biggest black hole may shed some light on the evolution of supermassive black holes.
Researchers at the National Astronomical Observatory of Japan (NAOJ) used the Nobeyama 45-meter Radio Telescope – single-dish radio telescope that operates in short-millimetre wavelengths – to detect the black hole. The findings could help answer the question of how supermassive black holes occur and grow at the core of large galaxies, according to the researchers.
There are two types of black holes known to astronomers so far: the supermassive black holes and the stellar-mass black holes. Supermassive black holes are often found at the centre of large galaxies, such as the Milky Way. In our galaxy, Sagittarius A* – a bright astronomical radio source at the centre of the Milky Way – is thought to be the location of a supermassive black hole and is approximately four hundred million times the mass of the Sun. Stellar-mass black holes occur after large stars release big explosions.
Tomoharu Oka, lead researcher and a professor in the Department of Physics at Keio University’s Faculty of Science and Technology, said that the Nobeyama 45-meter Radio Telescope detected something that appears to be an intermediate-mass black hole (IMBH) – located at about two hundred light-years from Sagittarius A*.
In the new paper – published in the Astrophysical Journal – researchers stated that the gas cloud CO-0.40-0.22 was caught in a gravitational storm that was pulling matter at various speed and in different directions. Using computer models, the team of researchers determined that a black hole was at the centre of the unusual storm. The intermediate-mass black hole, which is about one hundred thousand times the size of our sun, may be the second largest in the Milky Way galaxy.
Radio telescopes could become a new method of discovering intermediate-mass black holes. If intermediate-mass black holes are in fact very difficult to find, rather than exceptionally rare, then the new radio telescope technique could find numerous such black holes – which could answer questions about the evolution of our galaxy.
Some theories suggest that there are about one hundred million black holes throughout the Milky Way galaxy. However, only a fraction of that number has so far been detected through X-ray surveys, according to the researchers. If black holes do in fact grow by merging with other black holes, then the newfound intermediate-mass black hole may soon become a supermassive black hole.
Image Source: i1. web. de
