China's FAST Telescope Maps Neutral Hydrogen, a Cosmic Gas for Making Stars

China's Five hundred-meter Aperture Spherical Telescope (FAST) has compiled the world's largest catalogue of neutral hydrogen beyond the Milky Way. The FAST All-Sky H I Survey (FASHI) released its second batch of data, containing 156,411 extragalactic sources. This surpasses the previous main reference for mapping the gas that fuels the formation of stars and galaxies, a long-dominant US survey. The data was collected using the 500-metre radio dish in southwest China's Guizhou province. The catalogue will serve as a crucial tool for astronomers studying the universe, providing valuable insights into the formation and evolution of galaxies. The release of the second batch of data marks a significant milestone in the FASHI project, which aims to create a comprehensive map of neutral hydrogen in the universe. The data will be used to study the distribution and properties of neutral hydrogen, shedding light on the mysteries of the cosmos.