JWST reveals remarkably new insights into early star formation

"We're studying 19 of our closest analogs to our own galaxy. In our own galaxy, we can't make a lot of these discoveries because we're stuck inside it," says Erik Rosolowsky, professor in the Department of Physics and co-author of a recent paper analyzing data from the James Webb telescope. 

The penetration through the dust and gas 

In contrast to earlier observational methods, the telescope's mid-infrared equipment can penetrate dust and gas clouds to offer vital details about how stars are developing in these galaxies and 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." 

The telescope has so far collected data from 15 of the 19 galaxies. To classify what they saw, such as whether an image featured regular stars, massive star-forming complexes, or background galaxies, Rosolowsky and Hamid Hassani, a Ph.D. student and lead author on the paper, examined the infrared light emitted from dust grains at various wavelengths. 

"At 21 micrometers [the infrared wavelength used for the images collected], if you look at a galaxy you will see all of those dust grains heated with light from the stars," explains Hassani. 

Telescopic resolution severely restricted previous infrared studies of stellar nurseries, so they mainly concentrated on star clusters in the Milky Way, the Magellanic Clouds, and other neighboring galaxies in the Local Group. But the JWST's enormous 21-foot (6.5 meters) primary mirror gives it the strength to see considerably further into space, exposing previously unimaginable views.