The
Primeval Structure Telescope (PaST), also called
21 Centimetre Array (21CMA), is a Chinese radio telescope array designed to detect the earliest luminous objects in the universe, including the first stars, supernova explosions, and black holes. All of these objects were strong sources of
ultraviolet radiation, so they ionised the material surrounding them. The structure of this
reionisation reflects the overall density structure at the redshift of luminous-object formation.