The Seoul National University team on June 11 announced that a black hole has an average mass, about 10,000 times the mass of the Sun.
Previously, international academics have repeatedly announced the detection of medium mass black holes. However, this is the first time, a research team has published a report on medium-mass black holes that are firmly verified through reliable scientific research.
So far, most of the black holes are known to be in the form of small mass black holes, formed by a star dying, or a supermassive black hole, tens of thousands to billions times more massive. Solar.
Although researchers have known about the existence of black holes at the center of the NGC4395 dwarf galaxy , efforts to measure the mass of black holes all end in failure.
The Seoul National University team used the "echo of light" effect to measure the mass of black holes. "Echo of light" is the difference in time depending on the size of the black hole , between the light emitted from the accretion disk (the amount of huge material absorbed by the black hole) and the light emitted from surrounding gas clouds.
The team used about 20 telescopes worldwide from 2017 to 2018, measuring the "echo of light" effect , analyzing the measured results and making conclusions.
Korean researchers estimate that this is an important finding, that it is possible to connect the lost chain between the massive mass black hole and the small mass black hole, which is a clue to understanding "seed black hole " formed from the early stage of the universe.
The results of the study are published in the online edition of Nature Astronomy, a prestigious international academic journal.