the James Webb Space Telescope JWST has discovered what could be the oldest star clusters in the universe.
The James Webb Space Telescope has observed five protoglobular clusters — swarms of millions of stars bound together by gravity — within the Cosmic Gem Arc, a galaxy that formed just 460 million years after the universe began. the great explosion.
The Cosmic Gem Arc gets its name from its appearance: When viewed from our solar system, the starry galaxy appears like a thin crescent due to the strong gravitational influence of the foreground galaxy, which magnifies and distorts the appearance of the distant galaxy.
The galaxy is the most magnified region seen in the first 500 million years of our universe, giving astronomers an unprecedented window into how the movements of the first stars sculpted galaxies during the cosmic dawn.
Cosmic dawn is the time spanning the first billion years of the universe. Nearly 400 million years after the Big Bang, the era of reionization began, in which light from young stars stripped hydrogen of its electrons, creating electrons. Fundamental reconstruction of galactic structures.
“The early universe is not what we expected,” said the study’s first author Angela Adamo“Galaxies are much brighter, they form stars very quickly, and they do so in massive, dense star clusters,” the Stockholm University astronomer told Live Science. “We are building a new understanding of how early galaxies form.”
The researchers published their findings on June 24 in the journal nature.
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Lights on in the cosmic down
As stars form, They are throwing material In the form of winds and jets of ionized plasma – a process known as stellar feedback.
“To form these five star clusters, this small galaxy had to do so very efficiently,” Adamo said. “The stellar feedback from stars in star clusters must be enormous.”
Scientists discovered the Cosmic Jewel Arc in 2018 using the Hubble Space Telescope. Normally, galaxies this early emit light that is too faint to be detected by telescopes. But a phenomenon called gravitational lensing can help astronomers see it.
As Einstein explained in his book General theory of relativityGravity is the curvature and distortion of space-time in the presence of matter and energy. This curved space, in turn, sets the rules for how energy and matter move.
This means that although light travels in a straight line, the light can be bent and amplified due to the presence of gravity. In this case, the galaxy SPT-CL J0615-5746 lies between the cosmic jewel arc and our solar system, bending and amplifying the early galaxy’s light until it can be seen with telescopes.
By pointing the James Webb Space Telescope at this region of curved space, astronomers observed the cosmic gem arc in unprecedented detail, resolving the five globular clusters within it. They found that the clusters were incredibly dense, almost three times denser than star-forming regions observed near Earth.
The groups are among the first ever observed. Adamo said it is still unclear whether they were the first to be found or not.
“In principle, I expect that stars will form in a cluster manner even in completely primitive galaxies,” she added. “But to form [massive] For proto-globular clusters, the host galaxy must be able to create and retain a sufficient mass of gas. “So it all depends on how fast primitive galaxies grow.”
To learn more about the universe’s first embers in the region, researchers will continue spectroscopy using the James Webb Space Telescope. This will enable astronomers to reconstruct the physical properties of the clusters, further constrain their ages, and track the influence of the clusters’ stars on their wider galaxy.
