X-ray: NASA/CXC/Princeton Univ/C. Bambic et al.; Optical: SDSS; Radio: NSF/NRAO/VLA/ESO; Image processing: NASA/CXC/SAO/N.Wolk

NGC 4839 is approximately 1.5 million light-years across and holds the record for the galaxy group with the longest tail.

NASA’s Chandra X-ray Observatory (CXO) group of galaxies known as NGC 4839, with a log tail. From the analysis of this structure, we hope to better understand how galaxy clusters, which are some of the largest objects in the universe, managed to reach their size. This is what emerged from a study presented at the 242nd meeting of the American Astronomical Society in Albuquerque, New Mexico, and published in the June issue of Monthly Notices of the Royal Astronomical Society.

Galaxy clusters are groups of up to fifty galaxies that are gravitationally bound. Galaxy clusters are even larger, and instead can contain hundreds or thousands of galaxies. Both galaxy clusters and clusters of galaxies are enveloped in massive amounts of hot gas that are clearly visible in the X-ray range and account for a significant part of the mass in clusters or clusters of galaxies and are therefore essential to understanding these systems.

NGC 4839 lies near the edge of the Coma Cluster, one of the largest known clusters in the universe and lies about three hundred and forty million light-years from us. As NGC 4839 moves toward the center of this cluster, gas from the cluster is pulled along by gas from the cluster itself. This creates a kind of tail behind the galaxy cluster.

NGC 4839 is approximately 1.5 million light-years across (on the order of hundreds of thousands of times the distance between the Sun and the nearest star), and is the longest tail ever seen behind a galaxy cluster. Eventually the tail will merge with the hot gas already in the pool.