James Webb Telescope Has Uncovered Massive Galaxies From Cosmic Dawn
The James Webb telescope, a $10 billion space observatory that launched to the farthest reaches of the universe in July, has discovered six massive galaxies from cosmic dawn. One of them, researchers say, is 30 times smaller than our Milky Way, yet contains as many stars.
The pixelated dots of light that Webb found appear to be the remnants of ancient star systems, scientists report in the journal Nature. They look reddish because of their age, which is normal for stars and other celestial objects. That’s because the space around them is expanding, making their light stretch out to infrared wavelengths.
It’s unclear why these stars were so large when they were first forming. The current model of galaxy formation suggests that galaxies began as small clouds of stars and dust that grew over time. But if the astronomers’ findings are correct, that’s something they’ll need to rethink entirely, physicist Elijah Leja of Penn State tells New Scientist.
These spectra, which break down the observed light into different wavelengths, will help astronomers determine the true distance of these ancient galaxies, as well as their size and what they’re made of. This could help them better understand what happened to these early-day objects and determine if they really are the massive galaxies that Webb detected, or if they’re something else altogether.
What’s more, if these mysterious objects are real, they’ll be extremely distant from the big bang, which is 13.5 billion years old. That puts them in the most remote part of the cosmos, and it would push against the limits of our understanding of cosmology.
That’s why the team hasn’t ruled out any other possible explanation for the spotted objects, Nelson says. Currently, she and her colleagues are studying the data that Webb is sending back to Earth.
This information is being used to learn more about how the universe formed, which may allow astronomers to develop better models of the origins of our own galaxy. But it’s still too early to know how the discoveries will affect our current understanding of the universe.
The most interesting aspect of the results, according to astronomers, is that they show that the earliest galaxies were much larger and mature than what scientists previously believed. They have tens of billions of sun-like stars on par with the Milky Way.
As a result, the discoveries conflict with 99% of existing models that describe how galaxies formed. They call on astronomers to rethink fundamental understandings of how early galaxies formed and evolved, as well as the amount of matter that was needed for them to form.
These findings also suggest that the Milky Way’s spiral design is a misnomer, as it doesn’t reflect most of its mass. Instead, the Milky Way is composed of a patchwork of stars that are spread out in a circular shape. This is the way that most of the galaxies in our galaxy were shaped before they became galaxies, and it’s probably the reason for their massiveness, Leja said.