The smallest supermassive black hole was spotted at the center of a dwarf galaxy. Astronomers discovered the tiny black hole at NASA’s Chandra X-ray Observatory and the Magellan II telescope in Chile.
The study was published by the Astrophysical Journal Letters, and this finding will help astronomers better comprehend the evolutionary pattern of some of the earliest galaxies and the black holes at their core.
A dwarf galaxy is a small galaxy lacking in brightness, of a medium size, in between a regular galaxy and a globular cluster. A globular cluster means an aggregation of galaxies moving together through space.
A supermassive black hole is said to have a mass in the range of millions or billions of times that of the sun. Supermassive black holes are very dense, massive objects that cannot be penetrated by light.
About their formation, astrophysicists agreed on the fact that these are in place at the core of galaxies, that they can grow by attracting and congregating matter and even by merging with other black holes.
There are two variants of black holes, formed via different processes: the stellar-mass black hole and the minimum supermassive one.
However, a few intermediate-mass black holes have been observed.
Moreover, supermassive black holes formed very early in the Universe, at the heart of the first massive galaxies.
The newly-discovered tiny supermassive black hole was found at the core of the dwarf galaxy denominated RGG 118. It encompasses 50,000 suns’ worth of mass. To make a comparison, the Milky Way’s black hole holds approximately 4-5 million solar masses.
Elena Gallo, astrophysicist at the University of Michigan, co-author of the study, reported that most galaxies are relatively small, and while she and her team were convinced there would be a black hole at the core of each big galaxy, they were not sure if that was the case regarding smaller ones. They are harder to track down.
It was unknown whether the behavior of supermassive black holes at the heart of small galaxies was similar to that of black holes in big galaxies, she said.
RGG 118 is a small galaxy, which implies that it is unlikely to have merged with other galaxies to make the awe-inspiring structures that the wide cosmos encompasses today.
Prof. Gallo finally pointed out that the particular dwarf galaxies, with their tiny black holes, gave them the opportunity for further study regarding how black holes formed very early in the Universe.
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