How can a supermassive black hole be so teeny?
Astronomers have found the tiniest supermassive black hole ever to be detected to date.
An artist's conception shows a black hole surrounded by a disk of hot gas, and a large doughnut or torus of cooler gas and dust. The light blue ring on the back of the torus is due to the fluorescence of iron atoms excited by X-rays from the hot gas disk.
M.Weiss/CXC/NASA
The universe is full of surprises. Some of them can be the most telling paradoxes, and the latest discovery made by researchers at the University of Michigan is just that.
Astronomers have found the tiniest supermassive black hole ever to be detected to date. Located in the center of a dwarf disk galaxy called RGG 118 about 340 million light years from Earth, this oxymoronic object could unveil how larger black holes have evolved in their host galaxies since they formed at least 13 billion years ago.
“Black holes come in several different varieties," writes The Christian Science Monitor’s Noelle Swan.
“The smallest kind, called a primordial black hole, is the size of a single atom, but it contains the mass of a large mountain. The most widely understood black holes are known as stellar black holes and can contain 20 times the mass of the sun within a ball of space with a diameter of about 10 miles.”
Yet supermassive black holes, writes Ms. Swan, can be as vast as our entire solar system. Though the latest discovery has been described as “teeny,” – in our world – it’s anything but.
Astronomers estimate the black hole in RGG 118 is about 50,000 times the mass of the Sun. But it’s nearly 100 times less massive than the supermassive black hole found in the center of the Milky Way and 200,000 times “smaller” than the biggest black hole known to exist, reports the Chandra X-Ray Observatory.
While the astronomical object may be relatively small, it could lead to some pretty big discoveries.
"These little galaxies can serve as analogs to galaxies in the earlier universe," said Vivienne Baldassare, a doctoral student at the University of Michigan, Ann Arbor and co-author of the study, in a press release.
"For galaxies like our Milky Way, we don't know what it was like in its youth," said Ms. Baldassar. "By studying how galaxies like this one are growing and feeding their black holes and how the two are influencing each other, we could gain a better understanding of how galaxies were forming in the early universe."