Webb Telescope Discovers Hundreds of Ancient Galaxies in First Five Minutes of Universe

SPACE — The James Webb Telescope (Webb or JWST) has uncovered hundreds of ancient galaxies that were the first members of the universe. Webb’s findings are a leap from only a handful of galaxies known to exist at the start of the Big Bang.

A new study reports,

at 600 million years after the Big Bang, these very young galaxies exhibit complex structures and clusters of star formation. This research is part of an international collaboration called the JWST Advanced Deep Extragalactic Survey (JADES). This effort collected a month’s worth of observations from two small patches of sky; first in the constellation Ursa Minor and one in the direction of the Fornax cluster.

Scroll to read

Scroll to read

In this region there are more than 700 newly discovered early galaxies that reveal the appearance of the cosmos as it was in its early days.

“If you take the entire universe and condense it into a two-hour film, (the research area covers only) you see the first five minutes of the film,” said Kevin Hainline, research assistant professor at the Arizona Steward Observatory and lead author of the new study in announcing the discovery was made on Monday, June 5, 2023 at the 242nd meeting of the American Astronomical Society in Albuquerque.

“These are the galaxies that started the process of creating the elements and complexity that we see in the world around us today.”

These new findings shed light on how the first galaxies and stars formed, creating a rich catalog of the elements observed in the universe today. In just those five minutes, which marks the universe between 370 million and 650 million years old, Hainline and his colleagues studying Webb’s data found 717 young galaxies. That’s a lot more than previously predicted. Hundreds of galaxies span thousands of light years, have complex mechanical structures, and have given birth to stars in many clusters.

“Before, the earliest galaxies we could see looked just like tiny blotches. In fact, those blotches represented millions or even billions of stars in the early universe. Now, we can see that some of these are actually extended objects with visible structure.” Hailine said.

Together, the two regions used in this study are known as GOODS-South, short for The Great Observatories Origins Deep Survey, and have been studied extensively by nearly all major space telescopes, including Hubble, the Chandra X-Ray Observatory, and NASA. The now retired Spitzer. Despite previous research, 93 percent of the new galaxies Webb discovered during JADES had never been seen before.

“What we saw before was only the brightest and most extreme examples of bright galaxies in the early universe. Now we are actually investigating more normal, everyday galaxies in a young, turbulent universe,” Hainline said in his presentation Monday.

How chaotic and very dusty environment after the Big Bang

cleared into the transparent cosmos we see today has long been debated. A leading theory states that this phase of the universe’s evolution, called the Epoch of Reionization, occurred about 400,000 years after the Big Bang, when the first generation of stars formed and flooded the opaque universe with its first light. It is estimated that first-generation stars are 30 to 300 times the mass of our sun and millions of times brighter.

The ultraviolet starlight re-ionizes the universe by splitting its abundant hydrogen atoms into protons and electrons, a process that lasted up to a billion years after the Big Bang. However, some astronomers say an outflow from a supermassive black hole, similar to the one at the heart of our Milky Way, could trigger the release of ultraviolet radiation from the galaxy. Thus, it plays a more important role in cosmic evolution than previously thought.

Now, a second team from the JADES program that has studied galaxies that existed between 500 and 850 million years after the Big Bang, or between five and eight minutes of two-hour films depicting the universe, think it has the answer to that old question. “In these next views of the universe, we’re starting to really see the impact of galaxy formation on the composition of the universe at large,” said Ryan Endsley, a postdoctoral researcher at the University of Texas who led the second study in a news conference Monday.

“Galaxies in the earliest universe were much more chaotic in general in terms of how they formed stars.”

Endsley’s team studied signs of star formation in these earliest galaxies, which provided insight into how starlight ionized gas within galaxies. The team found that one in six galaxies at that time displayed extreme line emission in the galaxy’s spectrum, a feature emitted by atoms ionized by starlight when they cool and melt with other molecules.

The emission lines are evidence that early galaxies actively gave birth to stars, which then pumped “ultraviolet photon torrents” into each other’s galaxies. “In this way, the early stars of the universe became the main drivers of cosmic reionization,” said Endsley.

These extreme emission lines were relatively common in the early universe. Nearly every galaxy found exhibits signatures of unusually strong emission lines, indicating intense star formation. “These early galaxies were very good at creating hot, massive stars.”

From the same emission lines, Endsley’s team also concluded that galaxies in the early universe gave birth to stars in brief bursts followed by periods of quiescence. “Suddenly you’d have tens of suns’ worth of stellar mass clumped together in these early galaxies,” Endsley said.

According to him, the new knowledge is very important for the understanding of how reionization is caused by these hot massive stars. “They are also very efficient emitters of the ultraviolet photons we needed to ionize all the hydrogen in the early universe,” he said. Source: Space.com