Webb identifies the earliest strands of the cosmic web (annotated)

Galaxies are not scattered randomly 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 became more distinct over time as gravity drew matter together.

Astronomers for the ASPIRE program using the NASA/ESA/CSA James Webb Space Telescope have discovered a thread-like arrangement of 10 galaxies that existed just 830 million years after the Big Bang. This deep galaxy field from Webb’s NIRCam (Near-Infrared Camera) hosts these 10 distant galaxies. This 3 million light-year-long filament is anchored by a very distant and luminous quasar – a galaxy with an active, supermassive black hole at its core. The quasar, called J0305-3150, on the right side of the image, outshines its host galaxy. These 10 galaxies existed just 830 million years after the big bang. The team believes the filament will eventually evolve into a massive cluster of galaxies.

These results were published in two papers in The Astrophysical Journal Letters on 29 June 2023.

[Image description: Hundreds of tiny galaxies appear across the black expanse of space. The galaxy colours vary. At the bottom right are compass arrows indicating the orientation of the image on the sky. Below the image is a color key showing which NIRCam filters were used to create the image and which visible-light color is assigned to each filter.]