Pandora’s Cluster, also known as Abell 2744, is a giant galaxy located approximately 4 billion light-years from Earth in the constellation Sculptor. Previously, NASA’s Hubble Space Telescope had studied Pandora’s central core in detail.
Now, NASA’s James Webb Space Telescope features never-before-seen details in a region of space known as Pandora’s Cluster. In Webb’s view, three existing huge clusters of galaxies are seen merging to form a mega cluster.
By acting as a natural magnifying glass, the galaxy clusters’ combined mass produces a strong gravitational lens that makes it possible to detect many more distant galaxies in the early universe. The previously unknown view of Pandora’s Cluster combines four Webb images into one panoramic picture that shows almost 50,000 sources of near-infrared light.
Astronomer Rachel Bezanson of the University of Pittsburgh in Pennsylvania said, “The ancient myth of Pandora is about human curiosity and discoveries that delineate the past from the future, which I think is a fitting connection to the new realms of the universe. Webb is opening up, including this deep-field image of Pandora’s Cluster.”
“When the images of Pandora’s Cluster first came in from Webb, we were a little star-struck. There was so much detail in the foreground cluster and so many distant lensed galaxies. I found myself getting lost in the image. Webb exceeded our expectations.”
Astronomer Ivo Labbe of the Swinburne University of Technology in Melbourne, Australia, co-principal investigator on the UNCOVER program, said that “in the lensing core to the lower right in the Webb image, which Hubble has never imaged, Webb revealed hundreds of distant lensed galaxies that appear like faint arced lines in the image. Zooming in on the region reveals more and more of them.”
“Pandora’s Cluster, as imaged by Webb, shows us a stronger, wider, deeper, better lens than we have ever seen before. My first reaction to the image was that it was so beautiful; it looked like a galaxy formation simulation. We had to remind ourselves that this was real data, and we are working in a new era of astronomy now.”
The Cluster was observed by the UNCOVER team using Webb’s Near-Infrared Camera (NIRCam) over the course of around 30 hours of viewing time, with exposures lasting 4-6 hours each.
The next step is to carefully review the imaging data and choose galaxies for follow-up observation with the Near-Infrared Spectrograph (NIRSpec), which will provide accurate distance measurements along with other comprehensive information about the compositions of the lensed galaxies, providing new insights into the early stage of galaxy assembly and evolution.