A cluster of galaxies crackles with intricate detail in new images from the James Webb Space Telescope. JWST’s sharp infrared eyes show how newborn stars form their surroundings, providing hints at how stars and galaxies grow together.
“We were just amazed,” says Janice Lee, an astronomer at the University of Arizona in Tucson. She and more than 100 astronomers reported scientists’ first look at these galaxies with JWST in a special February issue Astrophysical Journal Letters .
Ahead of JWST’s launch in December 2021, Li and her colleagues selected 19 galaxies that they believed could reveal new details about stellar life cycles. These galaxies are relatively close, within 65 million light years of the Milky Way, and they all have different types of spiral structures. The team observed the galaxies with many observatories, but parts of the galaxies always looked flat and featureless.
“By using [JWST] we see structure down to the smallest scales,” says Lee. “For the first time, we’re seeing the youngest star-forming sites in many of these galaxies.”
In the new images, the faces of the galaxies are spotted as dark voids amid glowing filaments of gas and dust. Comparisons with Hubble Space Telescope images show that these voids are bubbles carved out of gas and dust by high-energy radiation from newborn stars at their centers.
Then, when the most massive of these stars reaches the end of its life and explodes, this gas is pushed out even more. Some of the larger bubbles have smaller bubbles at their edges, which may indicate places where gas ejected by dying stars has begun to build new stars.
Comparing these processes in different types of spiral galaxies will help astronomers understand how the shapes and properties of galaxies affect the life cycles of their stars, and how galaxies grow and change along with their stellar inhabitants.
“We studied only the first few [з 19 вибраних] galaxies,” says Lee. “We need to study these things in the full sample to understand how the environment changes … how stars are born.”
