Researchers got their first look inside a distant spiral galaxy to see how stars form and how they change over time, thanks to the James Webb Space Telescope’s ability to penetrate veils of dust and gas clouds. Credits: Science: NASA, ESA, CSA, Janice Lee (NOIRLab), Image Processing: Joseph DePasquale (STScI)
The Webb Space Telescope’s mid-infrared capability has allowed scientists to look past clouds of gas and dust to observe details previously hidden in distant galaxies.
Thanks to the powerful capabilities of the James Webb Space Telescope, the research team was able to see spiral galaxies deep within for the first time to study how they form and how they change over time.
“We are currently studying the 19 closest isotopes of our galaxy. In our own galaxy, we can’t make many of these discoveries because we’re stuck in it,” said Eric Rosulowski, a professor in the University of Alberta’s Department of Physics and Physics. co-author of the most recent paper — published in That[{” 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 are heated by starlight,” said Hassani.
From the collected images, they were able to determine the ages of the stars. They discovered that they were observing young, exploding stars.[ed] right on the scene, much quicker than many models anticipated,” said Rosulowski.
their age [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, separated by a sun visor: the hot side faces the Sun and Earth, and the cold side faces outer space away from the Sun and Earth. Solar panels, communication antennas, navigation systems, and electronic systems are located on the hot side facing the Sun and Earth. Mirrors and scientific instruments that are highly sensitive to infrared radiation are on the cool side, where they are protected by sun visors. Credit: STScI
The researchers also found a close relationship between the masses of stars in a region and how bright they are. “It turns out to be a great way to find high-mass stars,” said Rosulowski.
Rosolowsky called stars with high masses “rock stars” because they “live fast, die young, and form galaxies around them”. He explains that as they form, they release large amounts of solar wind and gas bubbles, which stop star formation in certain regions while simultaneously moving galaxies and triggering star formation in other regions.
“We’ve found that this is really key to the long-term life of galaxies, this type of volatile foam, because it keeps the galaxy from consuming its fuel too quickly,” said Rosulowski.
It’s a complicated process, added Hassani, with each new star formation playing a bigger role in how galaxies change over time.
“If you have star formation, the galaxy is still active. You have lots of dust and gas and all the emissions from this galaxy that are fueling the formation of the next generation of massive stars and keeping the galaxy alive.”
The more pictures scientists document of this process, the better they can deduce what is happening in distant galaxies similar to ours. Rather than just looking at one galaxy in depth, Rosulowski and Hassani wanted to create what Rosulowski calls a “galactic atlas” by taking pictures using as many methods as possible.
“By bringing all this data together, in creating this powerful atlas, we will be able to map out what sets one galaxy apart from the unifying features that make up the galaxy as a whole,” said Rosulowski.
References: “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, 16 Feb. 2023, Available Here Astrophysics Journal Letter.
DOI: 10.3847/2041-8213/aca8ab
Their paper is one of 21 papers on the early findings of physics in high-angle resolution at the Nearby Galaxies Collaboration (PHANGS), published in a special issue focused on Astrophysics Journal Letter.
