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Monday, June 5, 2023 (Halifax) _ An international team of astronomers has detected complex organic molecules in the most distant galaxy to date using NASA’s James Webb Space Telescope. The discovery of the molecules, which are familiar on Earth in smoke, soot and smog, demonstrates the power of Webb to help understand the complex chemistry that goes hand-in-hand with the birth of new stars even in the earliest periods of the universe’s history.

At least for galaxies, the new findings cast doubt on the old adage that where there’s smoke, there’s fire.

Using the Webb Telescope the team, including Dalhousie University astrophysicist Scott Chapman and Texas A&M University astronomer Justin Spilker, found the organic molecules (polycyclic aromatic hydrocarbons or PAH) in a galaxy more than 12 billion light years away. Because of its extreme distance, the light detected by the astronomers began its journey when the universe was less than 1.5 billion years old, about 10 per cent of its current age. The galaxy was first discovered by the National Science Foundation’s South Pole Telescope in 2013.

The discovery, published today in the journal Nature, was made possible through the combined powers of Webb and fate, with a little help from a phenomenon called gravitational lensing. Lensing, originally predicted by Albert Einstein’s theory of relativity, happens when two galaxies are almost perfectly aligned from our point of view on Earth. The light from the background galaxy is stretched and magnified by the foreground galaxy into a ring-like shape, known as an Einstein ring.

"This galaxy is one of the most luminous in the universe, forming stars at a very high rate -- 100s of times more rapidly than our own Milky Way. We were hoping to get new insights in the chemistry of the gas supply for forming stars to understand how galaxies like this are forming stars so rapidly," says Dr. Chapman, a professor in Physics and Atmospheric Science at Dalhousie.

The data from Webb found the telltale signature of large organic molecules akin to smog and smoke – building blocks of the same cancer-causing hydrocarbon emissions on Earth that are key contributors to atmospheric pollution. However, the implications of galactic smoke signals are much less disastrous for their cosmic ecosystems and are quite common in space. It was thought their presence was a sign that new stars were being created.

The new results from Webb show that this idea might not exactly ring true in the early universe.

"Thanks to the high-definition images from Webb, we found a lot of regions with PAH or 'smoke,' but no star formation, and others with new stars forming but no smoke," says Dr. Chapman. "This is very unlike local galaxies -- where if there's PAH, there are stars forming."

Discoveries like this are precisely what Webb was built to do: understand the earliest stages of the universe in new ways.

"This was incredibly exciting to get some of the first observations coming off the new JWST.  And extra exciting to see how powerful the telescope is, and how well it works," says Dr. Chapman.

The team, which included dozens of astronomers from around the world, says the discovery is Webb’s first detection of complex molecules in the early universe – a milestone moment seen as a beginning rather than an end.

“Detecting smoke in a galaxy early in the history of the universe? Webb makes this look easy. Now that we’ve shown this is possible for the first time, we’re looking forward to trying to understand whether it’s really true that where there’s smoke, there’s fire," says Dr. Spilker, an assistant professor in the Texas A&M Department of Physics and Astronomy.

"The only way to know for sure is to look at more galaxies, hopefully even further away than this one.” 

JWST is operated by the Space Telescope Science Institute under the management of the Association of Universities for Research in Astronomy, Inc.

Media contact:
Alison Auld
Senior Research Reporter
Communications, Marketing and Creative Services
Dalhousie University
Cell: 1-902-220-0491
Email: alison.auld@dal.ca

Author contacts:
Justin Spilker, Texas A&M University, jspilker@tamu.edu
Kedar Phadke, University of Illinois Urbana-Champaign, kphadke2@illinois.edu
Joaquin Vieira, University of Illinois Urbana-Champaign, jvieira@illinois.edu
Jane Rigby, NASA Goddard Space Flight Center, jane.r.rigby@nasa.gov
Shana Hutchins, Texas A&M University, shutchins@tamu.edu

This image is available in multiple resolutions: Spilker - JWST Smoke - Graphics: Astronomers using the Webb telescope discovered evidence of complex organic molecules similar to smoke or smog in the distant galaxy shown here. The galaxy, more than 12 billion light years away, happens to line up almost perfectly with a second galaxy only 3 billion light years away from our perspective on Earth. In this false-color Webb image, the foreground galaxy is shown in blue, while the background galaxy is red. The organic molecules are highlighted in orange. (Credit: J. Spilker / S. Doyle, NASA, ESA, CSA)

This image is available in multiple resolutions: Spilker - JWST Smoke - Graphics: The galaxy observed by Webb shows an Einstein ring caused by a phenomenon known as lensing. Lensing occurs when two galaxies are almost perfectly aligned from our perspective on Earth. The gravity from the galaxy in the foreground causes the light from the background galaxy to be distorted and magnified, like looking through the stem of a wine glass. Because they are magnified, lensing allows astronomers to study very distant galaxies in more detail than otherwise possible. (Credit: S. Doyle / J. Spilker)