SCIENCE

JWST’s most ambitious view is now available to everyone | by Ethan Siegel | Starts With A Bang! | May, 2025

This view represents more than 50% of the COSMOS-Web survey: the largest, deepest view of the Universe ever acquired with JWST. It provides us with our deepest wide-field view of the Universe ever taken, revealing how galaxies and larger structures evolve throughout cosmic history. (Credit: ESA/Webb, NASA & CSA, G. Gozaliasl, A. Koekemoer, M. Franco, and the COSMOS-Web team)

The COSMOS-Web survey is now complete, combining JWST and Hubble infrared data. Its spectacular views show us the Universe as never before.

Our Universe, today, contains trillions of galaxies with sextillions of stars.

Taking us beyond the limits of any prior observatory, including all of the ground-based telescopes on Earth as well as Hubble, NASA’s JWST has shown us the most distant galaxies in the Universe ever discovered. If we assign 3D positions to the galaxies that have been sufficiently observed-and-measured, we can construct a visualized fly-through of the Universe, as the CEERS data from JWST enables us to do here. At greater distances, compact, star-forming galaxies are more common; at closer distances, more diffuse, quiescent galaxies are the norm. (Credits: Frank Summers (STScI), Greg Bacon (STScI), Joseph DePasquale (STScI), Leah Hustak (STScI), Joseph Olmsted (STScI), Alyssa Pagan (STScI); Science by: Steve Finkelstein (UT Austin), Rebecca Larson (RIT), Micaela Bagley (UT Austin))

But 13.8 billion years ago, there were none at all.

In the aftermath of inflation, signatures are imprinted onto the Universe that are unmistakably inflationary in origin. While the CMB provides an early-time “snapshot” of these features, that’s just one moment in history. By probing the large variety of times/distances accessible to us throughout cosmic time, such as with large-scale structure, we can obtain information that would otherwise be obscure from any single snapshot. (Credit: Caltech/Robert Hurt(IPAC))

It takes both time and gravity for modern cosmic structures to evolve.

This snippet from a structure-formation simulation, with the expansion of the Universe scaled out, represents billions of years of gravitational growth in a dark matter-rich Universe. Over time, overdense clumps of matter grow richer and more massive, growing into galaxies, groups, and clusters of galaxies, while the less dense regions than average preferentially give up their matter to the denser surrounding areas. The “void” regions between the bound structures continue to expand, but the structures themselves do not. (Credit: Ralf Kaehler and Tom Abel (KIPAC)/Oliver Hahn)

To understand how it occurred, we need to map cosmic structure throughout history.

With appropriate measurements taken in a variety of wavelength filters, distances and lookback times can be inferred for each galaxy imaged in a deep field view of the Universe. Galaxies can be sorted into nearby, intermediate-distance, and great distance bins in the Universe. The earliest galaxies found in the deepest images of the Universe take us back to merely a few hundred million years after the Big Bang. (Credit: NASA, ESA, and Z. Levay, F. Summers (STScI))

This includes galaxies,


Source link

Related Articles

Back to top button