UH astronomer involved in major find
An international astronomy team that includes University of Hawaii astronomer Harald Ebeling has reported a powerful collision of galaxy clusters.
The "incredibly energetic collision" was captured with NASA's Chandra X-ray Observatory and Hubble Space Telescope, NASA officials announced last month.
Each of the two clusters that formed a new cluster was almost a million-billion times the mass of the sun and they merged at speeds of millions of miles per hour, NASA officials said. The hot gas in each cluster collided and slowed down but the dark matter did not, they said.
The new cluster, called MACSJ0025, shows a clear separation between dark and ordinary matter, NASA officials reported.
The finding is important, they said, because it verifies results found two years ago for the so-called Bullet Cluster and provides more evidence about dark matter and its properties.
The new cluster doesn't contain a "bullet" - a dense, bright X-ray core of gas seen moving through the Bullet Cluster, NASA said. "Nonetheless, the amount of energy involved in this mammoth collision is nearly as extreme as that found in the Bullet Cluster," a NASA news release said.
Dark matter makes up about 23 percent of the energy content of the universe, five times more than ordinary matter that can be detected by telescopes, NASA said.