By Will Dunham
WASHINGTON (Reuters) – The James Webb Space Telescope, operational since last year, has made groundbreaking observations of some of the universe’s earliest galaxies – what some astronomers have called “galactic infants.”
Recent research has determined that Webb has collected even more detailed data on galaxies that are a little further along in their development, comparable to what we might consider galactic “teenagers.” These galaxies, it turns out, bear some similarities to human teenagers, such as experiencing growth spurts and exhibiting a degree of immaturity.
The study focused on galaxies that formed about 2-3 billion years after the Big Bang, offering insights into their “chemical DNA” by analyzing light at various wavelengths from 23 such galaxies to create a composite image of teenage galactic characteristics.
“These teenage galaxies have very unique chemical DNA, suggesting that they have formed a significant number of stars – they’re fairly grown already – but are still growing rapidly,” said Allison Strom, lead author of the study and a professor at Northwestern University’s physics and astronomy department.
These teenage galaxies do not yet resemble or behave like the galaxies we observe today, according to the researchers.
“These galaxies undergo crucial processes during this period, many of which we do not yet completely understand but hope to better comprehend in the near future, which will determine the type of galaxies they will become,” said Gwen Rudie, co-leader of the study and an astronomer at Carnegie Observatories in California.
One intriguing finding was the detection of much hotter gas in the star-forming areas of teenage galaxies, at about 24,000 degrees Fahrenheit (13,350 degrees Celsius), compared to what is observed in present-day galaxies.
Rudie mentioned that more than just the observed eight elements probably exist within these galaxies, but have yet to be detected.
“Because elements heavier than hydrogen and helium are predominantly formed in stars, knowing what galaxies are made of tells us about how many stars they formed in the past and how quickly that happened,” Strom said.
“The findings point towards a scenario where these galaxies are still chemically ‘immature’ and are forming very rapidly,” Strom added.
Webb, launched in 2021, has reshaped our understanding of the early universe and is enabling new insights into the chemistry of distant galaxies with the first results from the CECILIA Survey using Webb. The name CECILIA stands for Chemical Evolution Constrained using Ionized Lines in Interstellar Aurorae, and honors pioneering astronomer Cecilia Payne-Gaposchkin.
“There has been a lot of excitement about how Webb has allowed us to view some of the very first galaxies. At the same time, the telescope is letting us observe galaxies a little later in the universe’s history in a stupendous amount of detail, and CECILIA is the first and best example of this,” Strom said.
(Reporting by Will Dunham, Editing by Rosalba O’Brien)
