Credit: X-ray: NASA/CXC/Leiden Univ./A. Botteon et al.; Radio: LOFAR/ASTRON; Optical/IR:PanSTARRS
When the titans of space — galaxy clusters — collide, extraordinary things can happen. A new study using NASA's Chandra X-ray Observatory examines the repercussions after two galaxy clusters clashed.
Galaxy clusters are the largest structures in the Universe held together by gravity, containing hundreds or even thousands of individual galaxies immersed in giant oceans of superheated gas. In galaxy clusters, the normal matter — like the atoms that make up the stars, planets, and everything on Earth — is primarily in the form of hot gas and stars. The mass of the hot gas between the galaxies is far greater than the mass of the stars in all of the galaxies. This normal matter is bound in the cluster by the gravity of an even greater mass of dark matter.
Because of the huge masses and speeds involved, collisions and mergers between galaxy clusters are among the most energetic events in the universe.
In a new study of the galaxy cluster Abell 1775, located about 960 million light years from Earth, a team of astronomers led by Andrea Botteon from Leiden University in the Netherlands announced that they found a spiral-shaped pattern in Chandra's X-ray data. These results imply a turbulent past for the cluster.