What impact does a black hole located at the center of a galaxy have on the entire galaxy? Recently, Professor Wang Tao's team and collaborators from the School of Astronomy and Space Sciences at Nanjing University revealed for the first time that the larger the mass of the black hole at the center of a galaxy, the lower the atomic hydrogen gas content of the entire galaxy, and the more likely the galaxy is to "age". The relevant results were published online on the 14th by the internationally renowned academic journal Nature. As the first author and corresponding author of the paper, Wang Tao introduced that the astronomical community generally divides galaxies into two categories: one is young galaxies that constantly produce new stars, known as "star forming galaxies"; The other type is "passively evolving galaxies", which are older and have almost no new star formation. Studying how the former transforms into the latter, that is, how galaxies age, is an important topic in the astronomical community. In the 1970s, theoretical scholars proposed that the massive energy released by supermassive black holes at the center of galaxies during the process of accreting matter would affect the evolution of galaxies. After decades of exploration, this viewpoint has become the core argument of the current mainstream theoretical models of galaxy evolution, but there has been a lack of clear observational evidence Wang Tao said. His team and collaborators have reviewed the observation data of neighboring galaxies from multiple observatories at home and abroad over the past 20 years. The analysis results show that the larger the mass of the black hole at the center of the galaxy, the lower the atomic hydrogen gas content of the entire galaxy, and the higher the possibility of this galaxy becoming a "passively evolving galaxy". Atomic hydrogen gas is the main component of cold gas in galaxies, and cold gas is the raw material for star formation Wang Tao said, "Due to the fact that black holes release energy during the process of accreting matter, the larger the mass of a black hole, the more energy is released, which will 'heat' or even directly 'blow away' cold gas, making it difficult to form new stars." The reviewer of Nature commented that this study directly links atomic hydrogen gas, the raw material for star formation, with black holes, which is of great significance for understanding the formation and evolution of galaxies. (New Society)