Want to visit the most distant galaxy in the early Universe? Now you can via a fantastic visualization created from JWST observations of some of the most distant galaxies ever seen.
The video takes a trip out to Maisie’s Galaxy. It began to form about 390 million years after the Big Bang and is one of the first bright galaxies to be seen during later part of the Epoch of Reionization. In cosmic terms, that’s like looking back at your baby picture when you were just an infant.
Maisie’s Galaxy is one of at least 100,000 galaxies that lie in a strip of sky between the constellations Ursa Major and Bootes. This “Extended Groth Strip” covers an area of sky about 70 arcminutes across and 10 arcminutes wide. An image of it was first made using 500 exposures from the Hubble Space Telescope’s Advanced Camera for Surveys. The strip is named for physicist Edward Groth and it contains about 50,000 known galaxies. This data is among large surveys of the early Universe that astronomers are using to understand galaxy formation throughout cosmic time.
Visualizing the Early Universe Seen by JWST
Credits: Visualization: Frank Summers (STScI), Greg Bacon (STScI), Joseph DePasquale (STScI), Leah Hustak (STScI), Joseph Olmsted (STScI), Alyssa Pagan (STScI)
JWST scientists focused on about 5,000 of the early galaxies in this new visualization, which is based on a massive set of observations made by the Cosmic Evolution Early Release Science Survey (CEERS) team. Maisie’s Galaxy is something that only JWST could see. “We couldn’t study galaxies like Maisie’s before because we couldn’t see them,” said team member Rebecca Larson. “Now, not only are we able to find them in our images, we’re able to find out what they’re made of and if they differ from the galaxies that we see close by.”
How CEERS Shows Us the Early Universe
Surveys of the earliest epochs of cosmic time keep pushing the boundaries of what we can “see” in the Universe. In particular, CEERS probes the period after the Big Bang when the first galaxies were forming. The project has many other ambitious goals. Among them are counting the early galaxies and showing their shapes and sizes. Astronomers know that galaxies began forming relatively soon after the Big Bang. What they want to see now is how they grew and evolved. Along with that, the team seeks to use JWST observations to study star formation in those very early times, as well as the growth of black holes. Those have been around as long as the Universe has existed, and their growth in the early Universe reveals more about stellar evolution and the fuels for black holes.
As astronomers study more galaxies at these high red-shift epochs, the team also wants to start looking for galaxies that have begun building structures such as bulges and disks. Those changes in shape (or morphology) contain a lot of clues about the abundances of gas and dust, as well as the earliest mergers between protogalaxies.
The period of time CEERS is focused on is roughly at the end of the Epoch of Reionization. That’s when the first light generated by stars and galaxies was able to travel through the expanding Universe. Galaxies were forming from the material in the interstellar medium, and their stars were forming. CEERS wants to characterize all the activities, from galaxy formation and early evolution to star formation rates.
What CEERS Shows
According to Steven Finkelstein, the principal investigator for the project, CEERS is delivering an amazing look at this early time. In particular, zooming into the Groth Strip provided more data than they expected. “This observation exceeded our expectations,” he said. “The sheer number of galaxies that we’re finding in the early universe is at the upper end of all predictions.” The observatory’s ability to conduct surveys like these provides a demonstration of Webb’s instruments for astronomers to reference for future observations.
The dive into the Groth Strip is sparking questions about what they’re seeing. For example, the formation of stars in early galaxies appears to be somewhat episodic and sudden. Such star burst activity is relatively common in colliding galaxies, for example. But it’s interesting to see it happening so early in history. “We’re used to thinking of galaxies as smoothly growing,” Finkelstein said. “But maybe these stars are forming like firecrackers. Are these galaxies forming more stars than expected? Are the stars they’re making more massive than we expect? These data have given us the information to ask these questions. Now, we need more data to get those answers.”
Built on Hubble’s Continuing Legacy
JWST’s accomplishment with CEERS is built solidly on work done for decades on the Hubble Space Telescope. HST paved the way with visible and near-infrared observations. However, in many cases, the views of the very earliest targets were obscured by dust, which blocks visible light. JWST and CEERS are digging in for more data further into the infrared. Now, data from both HST and JWST have enabled researchers to determine which galaxies were truly far away, giving them unprecedented views into the early Universe.
For More Information
New 3D Visualization Highlights 5,000 Galaxies Revealed by Webb
CEERS Web Page