Free Astronomy Magazine September-October 2023

24 such a long, distinctly thin structure.” “This is one of the earliest filamentary structures that people have ever found associated with a distant quasar,” added Feige Wang of the University of Arizona in Tucson, the principal investigator of this program. This discovery is from the ASPIRE proj- ect (A SPectroscopic survey of biased halos In the Reionization Era), whose main goal is to study the cosmic envi- ronments of the earliest black holes. In total, the program will observe 25 quasars that existed within the first billion years after the big bang, a time known as the Epoch of Reionization. “The last two decades of cosmology research have given us a robust un- derstanding of how the cosmic web forms and evolves. ASPIRE aims to understand how to incorporate the emergence of the earliest massive black holes into our current story of the formation of cosmic structure,” explained team member Joseph Hen- nawi of the University of California, Santa Barbara. G alaxies are not scattered ran- domly across the universe. They gather together not only into clusters, but into vast interconnected filamentary structures with gigantic barren voids in between. This “cosmic web” started out tenuous and be- came more distinct over time as grav- ity drew matter together. Astronomers using NASA’s James Webb Space Telescope have discovered a thread-like arrangement of 10 galax- ies that existed just 830 million years after the big bang. The 3 million light- year-long structure is anchored by a luminous quasar – a galaxy with an active, supermassive black hole at its core. The team believes the filament will eventually evolve into a massive cluster of galaxies, much like the well- known Coma Cluster in the nearby universe. “I was surprised by how long and how narrow this filament is,” said team member Xiaohui Fan of the University of Arizona in Tucson. “I expected to find something, but I didn’t expect Webb identifies the earliest strands of the cosmic web by NASA/ESA/CSA Ann Jenkins Christine Pulliam !