Washington: The James Webb Telescope has discovered that the early universe had more than 700 galaxies, a finding not known before.
Scientists led an investigation into galaxies that existed millions of years after the big bang. This was a crucial time known as the Epoch of Reionization. For hundreds of millions of years after the big bang, the universe was filled with a gaseous fog that made it opaque to energetic light. By one billion years after the big bang, the fog had cleared and the universe became transparent, a process known as reionization.
Kevin Hainline of the University of Arizona in Tucson and his team used Webb's NIRCam (Near-Infrared Camera) instrument and identified more than 700 candidate galaxies that existed when the universe was between 370 million and 650 million years old.
The sheer number of these galaxies was far beyond predictions from observations made before Webb's launch. The observatory's exquisite resolution and sensitivity are allowing astronomers to get a better view of these distant galaxies than ever before. "Previously, the earliest galaxies we could see just looked like little smudges. And yet those smudges represent millions or even billions of stars at the beginning of the universe," said Hainline.
"Now, we can see that some of them are actually extended objects with visible structure. We can see groupings of stars being born only a few hundred million years after the beginning of time."
The study is part of an international collaboration called the JWST Advanced Deep Extragalactic Survey (JADES), which gathered observations from two tiny patches in the sky: One in the Ursa Minor constellation and another in the direction of the Fornax cluster. These new findings shed light on how the first galaxies and stars formed, creating the rich catalogue of elements observed in the universe today.
However, the researchers stated that 93 per cent of the newfound galaxies had never been seen before. "We're finding star formation in the early universe is much more complicated than we thought," Marcia Rieke of the University of Arizona in Tucson, co-lead of the JADES programme. The findings were reported at the 242nd meeting of the American Astronomical Society in Albuquerque in New Mexico. —IANS
