At least 7,000 galaxies were photographed in a glittering deep field picture in one of the first photos from the James Webb Space Telescope (JWST or Webb) to be made public. The image was released on July 11, 2022. For scientists looking to understand more about how galaxies evolve over time, the image is a treasure trove.
Large groups of stars up to 10 billion light-years away from Earth are seen in the image according to a recent study headed by Canada that is the first to determine galactic distances in the field. (The age of the cosmos is roughly 13.7 billion years.)
“The clusters represent ideal targets for future studies to better understand how galaxies and the clusters they inhabit have evolved,” research team members stated in a University of Montreal press release from Oct. 31.
Looking far into the cosmos to find alterations since the Big Bang, the event that created and quickly expanded our universe, is a major component of JWST’s goal. What happened after that is still a mystery to astronomers; they want to know how light came into being, how stars formed, and when the first galaxies collided.
The $10 billion NASA telescope, equipped with a suite of potent equipment, was launched in December 2021. Among them was the Near Infra-Red Imager and Slitless Spectrograph (NIRISS) of Canada, which is designed to collect light signatures, or spectra, from far-off stars and galaxies. Redshift, or the stretching of light toward the red edge of the spectrum as a result of the universe’s expansion drawing the bright object away from us, is one way that spectra disclose information about an object’s distance.
“NIRISS is perfect for doing this because it can measure the redshifts of hundreds of galaxies at once,” lead author Gaël Noirot, a postdoctoral researcher at Saint Mary’s University in Halifax, Nova Scotia, said in the statement. “Our recently published study will be a valuable resource for the astronomical community, and open up new avenues of research.”
The study discovered new galaxies in the massive galaxy cluster known as SMACS 0723, whose light traveled over 4 billion years to reach Earth. Scientists are still collecting this data to find out more about how dark matter affects the structures. Roughly 80% of the mass of the universe is made up of dark matter, which influences things like the pace of expansion. Charting it is challenging, though, because it is only apparent through gravitational impacts.
There were other discoveries as well. Three objects that have densities higher than those expected in a solitary galaxy known as overdensities were discovered by the researchers. The finding implies that three recently discovered galaxy clusters, located between eight and ten billion light-years away, might be housed in SMACS 0723.
What’s more, one of these overdense regions hosts the “Sparkler Galaxy” revealed in September 2022. Sparkler is nine billion light-years away and could host the universe’s first star clusters. The newly found overdensities suggest the Sparkler is not an isolated example.