Breathtaking early stages of star formation captured by the James Webb Space Telescope

Researchers get their first glimpses inside distant spiral galaxies to see how stars formed and how they change over time, thanks to the ability of the James Webb Space Telescope to pierce the veil of dust and gas cloud. Credit: Science: NASA, ESA, CSA, Janice Lee (NOIRLab), Image Processing: Joseph DePasquale (STScI)

The mid-infrared capabilities of the Webb Space Telescope have allowed scientists to see past clouds of gas and dust to observe details previously obscured in distant galaxies.

Thanks to the powerful capabilities of the James Webb Space Telescope, a team of researchers has been able to see the distant spiral galaxies within them for the first time to study how they form and how they change over time.

“We’re studying 19 of our galaxy’s closest isotopes. In our own galaxy, we can’t make many of these discoveries because we’re stuck inside it,” says Eric Rosulowski, a professor in the University of Alberta’s Department of Physics and co-author of a recent paper — published in the[{” attribute=””>Astrophysical Journal Letters — analyzing data from the James Webb telescope.

Unlike previous observation tools, the telescope’s mid-infrared instrument can penetrate dust and gas clouds to provide critical information about how stars are forming in these galaxies, and consequently, how they are evolving.

“This is light that is longer wavelength and represents cooler objects than the light we see with our eyes,” says Rosolowsky.

“The infrared light is really key to tracing the cold and distant universe.”

James Webb Space Telescope artist concept. Credit: NASA

So far, the telescope has captured data from 15 of the 19 galaxies. Rosolowsky and Hamid Hassani, a PhD student and lead author on the paper, examined the infrared light emitted from dust grains at different wavelengths to help categorize what they were seeing, such as whether an image showcased regular stars, massive star-forming complexes or background galaxies.

“At 21 micrometers [the infrared wavelength used for the images collected]“If you look at a galaxy, you will see all the dust grains being heated by starlight,” Hassani explains.

From the images collected, they were able to determine the age of the stars. They discovered that they were observing young stars that were “exploding”.[ed] on the scene practically immediately, much faster than a lot of models would have anticipated,” Rosulowski says.

The age of those [stellar] The population is very young. They are just starting to produce new stars and are really active in star formation.

Webb has two sides, divided by a sun visor: a hot side facing the Sun and Earth, and a cold side facing space away from the Sun and Earth. The solar panels, communications antenna, navigation system, and electronic systems are located on the hot side facing the Sun and Earth. Mirrors and scientific instruments that are very sensitive to infrared radiation are on the cool side, where they are protected by a sun visor. Credit: STScI

The researchers also found a close relationship between the mass of stars in a region and how bright they are. “It turned out that this was a great way to find high-mass stars,” says Rosulowski.

Rosolowsky calls high-mass stars “rock stars” because they “live fast, die young, and shape the galaxy around them.” He explains that when they form, they release huge amounts of solar wind and gas bubbles, which stop star formation in that particular region, while simultaneously moving the galaxy and triggering star formation in other regions.

“We’ve discovered that this is really key to the long-term life of the galaxy, this kind of volatile froth, because it keeps the galaxy from going through its fuel too quickly,” Rosulowski says.

It’s a complex process, Hassani adds, with each new star formation playing a larger role in how the galaxy changes over time.

“If you have star formation, that galaxy is still active. You have a lot of dust and gas and all these emissions from the galaxy that are spurring the next generation of massive star formation and keeping the galaxy alive.”

The more images scientists document of these processes, the better they can deduce what is happening in distant galaxies that are similar to ours. Rather than looking at just one galaxy in depth, Rosulowski and Hassani want to create what Rosulowski calls a “galaxy atlas” of sorts by taking images using as many methods as possible.

“By bringing together all of this data, in creating this great atlas, we will be able to map out what distinguishes a single galaxy versus the unifying features that make up galaxies as a whole,” Rosulowski says.

Reference: “PHANGS-JWST First Results: 21 μM Compact Population Source” by Hamid Hassani, Eric Rosolosky, Adam K. , Melanie Schiffans, Daniel A. Dale, Oleg F. Egorov, Eric Emsselm, Christopher M. Weissey, Kathryn Gracha, Jaeun Kim, Ralph S. Karen M. Sandstrom, Eva Schinerer, David A. Thelker, Elizabeth J. Watkins, Bradley C. Whitmore and Thomas G. Williams February 16, 2023, Available here. Astrophysical Journal Letters.
DOI: 10.3847/2041-8213/aca8ab

Their paper was one of 21 papers on the preliminary findings of physics in high angular resolution in the Collaboration of Nearby Galaxies (PHANGS), published in a special issue focusing on Astrophysical Journal Letters.