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 interiors of distant spiral galaxies for the first time to study their formation and evolution over time.
“We are studying 19 of our closest isotopes in our galaxy. In our galaxy, we can’t make many of these discoveries because we’re stuck indoors,” says Eric Rosulowski, a professor in the University of Alberta’s Department of Physics and co-author of a paper. Recently – 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 these grains of dust getting heated up by starlight,” Hosni says.
From the images collected, they were able to determine the age of the stars. They discovered that they noticed young stars that were “exploding.”[ed] on the scene almost immediately, much faster than many models expected,” says Rosulowski.
“The age of these [stellar] The population is very young. They are really starting to produce new stars and they are really active in building stars,” Hosny says.
A web has two sides, separated by a sun visor: a warm side facing the sun and the earth, and a cold side facing into 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 discovered a close relationship between the mass of stars in a region and their luminosity. “It turned out to be a great way to find high-mass stars,” says Rosulowski.
Rosolowsky calls high-mass stars “rock stars” because they “live fast, die young, and really 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 stimulating the galaxy and spurring star formation in other regions.
“We found that this kind of bubble foam is really necessary for long-term galactic life, because it keeps the galaxy from going through its fuel too quickly,” Rosulowski says.
It’s a complex process, El-Hassani adds, with each new star formation playing a larger role in how the galaxy evolves over time.
“If you have a star formation, that galaxy is still active. You have a lot of dust and gas and all that emissions from the galaxy that lead to the next generation of the next massive star formation and keep the galaxy alive.
The more images scientists document of these processes, the better they will be able to deduce what is happening in distant galaxies similar to our own. Rather than looking at a single galaxy in depth, Rosolowsky and Hassani want to create what Rosolowsky calls a kind of “galaxy atlas” by taking images using as many methods as possible.
“By collecting all of this data, and creating this big atlas, we’ll be able to map out what characterizes a 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. Letters from The Astrophysical Journal.
DOI: 10.3847 / 2041-8213 / aca8ab
Their paper was one of 21 papers on early results from the Physics of High Resolution Collaboration in Nearby Galaxies (PHANGS), published in a special issue of Letters from The Astrophysical Journal.