Using data from NASA's Chandra X-ray Observatory, astronomers found that multiple eruptions from a supermassive black hole over 50 million years ago have rearranged the cosmic landscape at the centre of a group of galaxies.Scientists discovered this history of black hole eruptions by studying NGC 5813, a group of galaxies about 105 million light years from Earth. These observations are the longest ever obtained of a galaxy group, lasting for just over a week. The erupting supermassive black hole is located in the central galaxy of NGC 5813.The researchers were able to determine the length of the black hole's eruptions by studying cavities, or giant bubbles, in the multi-million degree gas in NGC 5813.
These cavities are carved out when jets from the supermassive black hole generate shock waves that push the gas outward and create huge holes.Galaxy groups are like their larger cousins, galaxy clusters, but instead of containing hundreds or even thousands of galaxies like clusters do, galaxy groups are typically comprised of 50 or fewer galaxies.Like galaxy clusters, groups of galaxies are enveloped by giant amounts of hot gas that emit X-rays. A paper describing these results was published in the Astrophysical Journal.