Astronomers Measure Tiny Black Hole In Nearby Galaxy

A newly discovered black hole in a nearby dwarf galaxy could provide scientists a deeper understanding of how its larger counterparts were formed. According to researchers, the black hole’s small size makes it easier to measure and study than the larger ones.

The black hole was discovered at the center of the galaxy NGC 4395 by a team of researchers including astronomer Elena Gallo of the University of Michigan. The results of their study were published in the scientific journal Nature Astronomy.

Although scientist are already aware that black holes appear in the center of large galaxies such as the Milky Way, further studies are yet to be conducted on how they form in dwarf galaxies. Through the new study, researchers are hoping to get an idea of how massive black holes are formed by studying a smaller one.

In order achieve this, Gallo and her team first measured the size of the small black hole they discovered. Through reverberation mapping, they used the radiation emitted by an accretion disk around the black hole. The accretion disk is a mass of matter that was accumulated due to the gravitational pull of black holes.

As the radiation moves away from the accretion disk, it goes through a mass of material known as the broad-line region and causes flashes to appear. By measuring the time it took for the radiation to reach the broad-line region, the researchers were able to get an idea of the tiny black hole’s mass.

“The distance is thought to depend on the black hole mass,” Gallo said in a press release. “The larger the black hole, the larger the distance and the longer you expect for light to be emitted from the accretion disk to hit the broad-line region.”

Through their observations, the researchers concluded that the black hole has a mass 10,000 times that of the Sun.

Aside from applying the same technique to measure the mass of larger black holes, Gallo noted that the new study could be used in analyzing how black holes reach massive sizes.

“Black holes somehow shape the galaxy they live in on very large scales, and because we don’t know much about smaller galaxies with their smaller black holes, we don’t know whether that’s true all the way down,” Gallo said. “With this measurement, we can add more information to this relationship.”