New Map Of The Cosmic Web Is The Most Detailed Map

Using data from NASA’s James Webb Space Telescope, astronomers have produced the most detailed map of the cosmic web ever made.

This article was written by Iqbal Pittalwala – UC Riverside and originally published by Futurity.

The work traces the network of galaxies all the way back to when the universe was one billion years old.

The cosmic web is the universe’s vast, skeleton-like framework—a network of interwoven filaments and sheets of dark matter and gas that surround immense, nearly empty voids. It forms the underlying architecture of the cosmos, linking galaxies and clusters into a single, intricate, and far-reaching structure.

The study in The Astrophysical Journal used the largest James Webb Space Telescope (JWST) survey conducted so far—the COSMOS-Web—to trace how galaxies form a network across 13.7 billion years of cosmic history.

Since its launch in 2021, JWST has transformed astronomy with its extraordinary sensitivity and sharpness. Its infrared instruments pick up faint, distant galaxies that were invisible to earlier observatories, allowing scientists to see further back in time than ever before, and through cosmic dust.

To harness this power, an international team designed COSMOS-Web, the largest General Observer (GO) program selected for JWST. The GO program is the primary way astronomers gain access to the telescope for their research. Covering a contiguous area of the sky about the size of three full Moons, the survey was designed to map the cosmic web.

“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,” says Hossein Hatamnia, a graduate student at University of California, Riverside and Carnegie Observatories, and lead author of the study.

“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.”

The nearby universe refers to our cosmic neighborhood within approximately 1 billion light-years. Approximately 5.88 trillion miles, a light-year is the distance light travels in one Earth year, used to measure massive distances in space.

Bahram Mobasher, a distinguished professor of physics and astronomy at UCR and Hatamnia’s advisor, explains that the large-scale structure identified from the JWST cosmic web data is much more informative than earlier maps of the same region of sky taken by the Hubble Space Telescope. A direct side-by-side comparison, he says, shows how much the previous generation of data had been smoothing over structures.

“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 says.

“What used to look like a single structure now resolves into many, and details that were smoothed away before, are now clearly visible.”

Hatamnia explains that the improvement comes from two JWST strengths working together.

“The telescope detects many more faint galaxies in the same patch of sky, and the distances to those galaxies are measured far more precisely,” he says. “Each galaxy can therefore be placed into the correct slice of cosmic time, sharpening the map’s resolution.”

In keeping with COSMOS’s long tradition of open science, the team is releasing the large-scale structure maps publicly.

“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 says.

Mobasher and Hatamnia were joined in the study by scientists in the US, Denmark, Chile, France, Finland, Switzerland, Japan, China, Germany, and Italy.

The study was supported by grants from the European Union’s Horizon 2020 research and innovation program.

Source: UC Riverside