Jeon Ji-gook (left), professor of astronomy and space science at Yonsei University, and first author Hyung-jin Joo. Courtesy of Yonsei University
Cluster light is the light produced by stars wandering between galaxies in a cluster of hundreds of galaxies. Astronomers have debated the origins of the light-producing wandering stars. The claim that the wandering star was created recently and the claim that it was created in the early days of the universe collided.
A research team in Korea has come up with research findings that put an end to this debate. He succeeded in detecting light within galaxy clusters created by wandering stars in galaxy clusters in the early stages of the universe.
A research team led by Professor Jeon Ji-kook of the Department of Astronomy and Astronomy at Yonsei University announced that the research results were published in the international journal “Nature” on the 5th.
The research team used NASA’s Hubble Space Telescope to detect the infiltration of galaxy clusters created by wandering stars in 10 initial galaxy clusters that are only a third of the current age of the universe. The brightness of the internal light of this galaxy cluster is about 17% of the light produced by the cluster as a whole, similar to today’s measurements in the nearby universe.
The research team said: ‘The fact that many wandering stars have been discovered in young clusters of galaxies means that wandering stars formed in large numbers in the early universe.’
Wandering stars are supposed to be used as “dark matter” tracers. Dark matter accounts for 85% of the total mass of matter that makes up the universe, but its identity is still unknown. It does not interact with normal matter other than gravity and is invisible. The identity of dark matter remains one of the greatest challenges of physics in the 21st century.
Professor Ji explained why a wandering star can be used as a dark matter tracker by comparing it to an invisible man. However, if the amount of flour is not enough, only a part of the shape such as the head or arms is visible.
Wandering stars play a role in spreading the flour. It is explained that the wandering star, which is shown to have been created in the early universe, must have interacted with dark matter through gravity as it traveled around the galaxy cluster. Professor Ji said, “Where dark matter goes, the wandering star must have moved with it.”
In 2007, Professor Ji published a study that found evidence proving the existence of dark matter using gravitational lensing. At the time, it was rated as the most compelling piece of evidence in the history of dark matter research.
