Astronomers using NASA’s James Webb Space Telescope have created the most detailed map yet of the universe’s vast cosmic web, revealing how galaxies connected and evolved across 13.7 billion years of history.
The new map gives scientists an unprecedented look at the large-scale structure of the universe during its earliest stages. Researchers traced galaxy networks back to a time when the universe was only about one billion years old.
The cosmic web forms the backbone of the universe. It consists of enormous filaments of dark matter and gas that connect galaxies and galaxy clusters across space. Massive empty voids lie between these structures.
Researchers from the University of California, Riverside, led the effort using data from COSMOS-Web, the largest survey conducted so far with the James Webb Space Telescope. The project mapped a region of sky roughly equal to the size of three full Moons.
Mapping ancient structures
The James Webb telescope’s infrared instruments allowed astronomers to detect faint galaxies hidden from older observatories. The telescope also measured galaxy distances with far greater precision.
“JWST has completely changed our view of the universe, and COSMOS-Web was designed from the start to give us the wide, deep view we need to see the cosmic web,” said Hossein Hatamnia, a graduate student at UCR and Carnegie Observatories, and lead author of the study.
COSMOS-Web map traces galaxies across nearly 14 billion cosmic years. Credit – UCR/Hossein Hatamnia
“For the first time we can study the evolution of galaxies in cluster and filamentary structures across cosmic time, all the way from when the universe was a billion years old up to the nearby universe,” he added. The nearby universe refers to regions within about one billion light-years of Earth.
Sharper than Hubble
Researchers compared the new data with earlier observations from the Hubble Space Telescope. They found that Webb revealed structures that Hubble could not clearly separate. Bahram Mobasher, a distinguished professor of physics and astronomy at UCR, said older maps blurred many details together.
“The jump in depth and resolution is truly significant, and we can now see the cosmic web at a time when the universe was only a few hundred million years old, an era that was essentially out of reach before JWST,” Mobasher said. “What used to look like a single structure now resolves into many, and details that were smoothed away before, are now clearly visible,” he added.
Hatamnia said the improvement came from Webb’s ability to identify many more faint galaxies in the same area of space. The telescope also placed those galaxies into more accurate slices of cosmic time.
Public data release
The research team has now released the maps and related tools to the public. Scientists worldwide can access the data, including a catalog containing information on 164,000 galaxies.
“The pipeline used to build the map, the catalog of 164,000 galaxies and their cosmic density, and a video showing the cosmic web evolving across billions of years, has been released to the public,” Mobasher said.
The study is published in The Astrophysical Journal.