Astronomers using the Webb telescope discovered evidence of complex organic molecules in a galaxy more than 12 billion light-years away. The galaxy lines 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
Key points:
- Researchers have detected complex organic molecules in a galaxy more than 12 billion lightyears away.
- The molecule, called PAH, is considered the basic building block for the earliest forms of life.
- The power of the JWST enabled the finding, shedding light on the complex chemical interactions that occur in the first galaxies in the early universe.
Using the James Webb Space Telescope (JWST), researchers have detected complex organic molecules in a galaxy more than 12 billion light years away—the most distant galaxy in which these molecules are now known to exist.
A new study published in Nature lends gives critical insight into the complex chemical interactions that occur in the first galaxies in the early universe.
In the new study, international researchers collaborated to differentiate between infrared signals generated by the massive and larger dust grains in the galaxy and those of the newly observed hydrocarbon molecules.
The team focused the JWST on SPT0418-47, an object discovered using the National Science Foundation’s South Pole Telescope and previously identified as a dust-obscured galaxy magnified by a factor of about 30 to 35 by gravitational lensing.
Spectroscopic data from the JWST suggest that the obscured interstellar gas in SPT0418-47 is enriched in heavy elements, indicating that generations of stars have already lived and died. The specific compound the researchers detected is a type of molecule called polycyclic aromatic hydrocarbon, or PAH. On Earth, these molecules can be found in the exhaust produced by combustion engines or forest fires. Being comprised of carbon chains, these organic molecules are considered the basic building blocks for the earliest forms of life.
“What this research is telling us right now, and we are still learning, is that we can see all of the regions where these smaller dust grains are located—regions that we could never see before the JWST,” said study author Kedar Phadke, graduate student at University of Illinois Urbana-Champaign. “The new spectroscopic data lets us observe the galaxy’s atomic and molecular composition, providing very important insights into the formation of galaxies, their lifecycle and how they evolve.”