This pair of images represents an extraordinarily large survey of galaxies studying the slowdown of supermassive black hole growth from about ten billion years ago, when their growth was at its peak, to today. Galaxy 2CXO J033225.7-274936 glows more strongly in X-rays than 2CXO J033215.3-275044 because it is consuming material more quickly. Astronomers used Chandra, XMM-Newton, and eROSITA data to study about 1.3 million galaxies and 8,000 supermassive black holes. The team found that black holes’ consumption of material has greatly slowed down as the universe has aged, probably because the amount of cold gas available for them to ingest has decreased