[The Epoch Times, April 29, 2022](The Epoch Times reporter Di Rui compiled and reported) Astronomers have determined that the mass between 100 times and 100,000 times the mass of the sunblack holecalledmedium black hole. Such black holes are rare.A new study suggests they may be in some galaxiesnuclear cluster(nuclear star cluster).
Over the past few decades, astronomers have detectedblack holeThere are mainly two types, one is a small black hole with a mass only a hundred times less than the sun, and the other is a super black hole with a mass millions of times the sun.medium black holeWhy it is so rare has always been a mystery.
Scientists generally believe that medium-sized black holes exist, but there are two types of theories.”Most theories suggest that the formation of these black holes depended on the conditions of the very early universe,” said lead investigator Vivienne Baldassare, assistant professor of physics and astronomy at Washington State University. . We want to test another class of theories—they are some of the densernuclear clusterformed within. “
Nucleus clusters, also called compact nuclei, are high-density star clusters in most galaxies, near their central regions. This type of star cluster is the densest star cluster structure known to astronomers to date.
Therefore, the research group used theChandra X-ray Observatory(Chandra X-ray Observatory) to look for traces of these black holes. The Chandra X-ray Observatory, a space telescope orbiting the Earth, is the most powerful X-ray detector in the world today, capable of detecting very faint X-rays from distant space. The researchers focused on the nuclear clusters in 108 galaxies to look for clues regarding black holes.
The analysis revealed that nuclear clusters above a certain mass emit twice as much X-rays characteristic of black holes as those below this mass. In addition, the research team also found some evidence that the internal environment of this nuclear cluster is suitable for small black holes to grow into medium-sized black holes.
Therefore, the research team believes that nuclear star clusters with masses exceeding a certain value are suitable for the growth of black holes, and it is very likely that many nuclear star clusters contain medium-sized black holes. “The evidence we found means that the environment inside a sufficiently massive, dense star cluster is capable of forming black holes,” Baldassare said. This provides exciting new clues for the search for medium-sized black holes.
The study was published April 14 in The Astrophysical Journal. ◇#
Responsible editor: Ye Ziwei
