This image shows the Webb Deep Field of Galaxies, the very first unveiled science image by JWST. Credits: NASA, ESA, CSA, STScI. Post-stamps: Shannon MacFarland (SMU).
Dr. Gaël Noirot, a postdoctoral researcher at Saint Mary’s University, is playing a leading role in studying an image called “Webb’s Deep Field of Galaxies,” the extraordinary first image produced by the James Webb Space Telescope (JWST) which contains at least 7,000 galaxies.
Along with Saint Mary’s professor and CRC Chair Dr. Marcin Sawicki, a team of Canadian astronomers have used the Canadian NIRISS instrument on board JWST to collect spectra from galaxies in the image. These spectra are a type of scientific data created by breaking down the light of an object to reveal additional information such as the object’s age or distance.
The team has now measured the redshifts—a precise measurement of a galaxy’s distance based on the unique chemical signatures seen in its spectra—of nearly 200 galaxies whose distances from Earth were previously unknown.
“NIRISS is perfect for doing this because it can measure the redshifts of hundreds of galaxies at once,” said Dr. Noirot who is Principal Investigator of this observing program and lead author of the study published this month in the Monthly Notices of the Royal Astronomical Society.