The James Webb Space Telescope has peered into another ancient Hubble Space Telescope target, this time revealing startling details in a distant galaxy as it existed shortly after the big bang at the dawn of the universe.
Nasa released the new Webb Telescope image Wednesday morning in a blog post that also included an interview with the scientists behind the sighting, astronomer Dan Coe of the Space Telescope Science Institute, Baltimore, Tiger Yu-Yang Hsiao, an astronomer at Johns Hopkins University. , and Rebecca Larson, an astronomer from the University of Texas at Austin.
The target of the scientists’ ongoing search is MACS0647-JD, a distant galaxy billions of light-years away first discovered by Dr Coe 10 years ago using the Hubble telescope.
“With Hubble it was just this faint red dot. We could tell it was really small, just a tiny galaxy in the first 400 million years of the universe,” he said. , we are watching with Webb, and we are able to resolve TWO objects! We are actively discussing whether they are two galaxies or two star clusters within a galaxy.
“It’s really interesting to see two structures in such a small system,” Dr. Hsiao added in a statement. “We may be seeing a merger of galaxies in the very early universe.”
MACS0647-JD is not immediately noticeable in the sea of gem-like galaxies seen in the recently released image. Scientists cannot directly see galaxies that far away, even with the powerful Webb Telescope. So they instead use the gravity of a massive star cluster between Webb and MACS0647-JD to magnify the image of the background galaxy, a technique known as gravitational lensing.
In this case, scientists used the gravity of a star cluster known as MACS0647 as a “lens” to study the MACS0647-JD galaxy. The lensing process makes the background galaxy appear in three different places in the main image, which are indicated and then magnified in a sidebar.
“Due to the gravitational lensing of the massive galaxy cluster MACS0647, it is split into three images: JD1, JD2 and JD3,” Dr Coe said. “They are amplified by factors of eight, five and two, respectively.”
Studying these extremely distant galaxies can help scientists understand how the very first galaxies formed and evolved, and from there, better understand how our own galaxy came into existence and what its ultimate fate might look like. .
The Webb Telescope was launched in December 2021 after more than 20 years of development designed to allow it to study only these kinds of extremely distant objects, and according to Dr Larson, this is just the beginning.
“I think my favorite part is that for so many new Webb images that we’re getting, if you look in the background, there are all these little dots – and they’re all galaxies! All of them,” she said in a statement, “And it’s not a deep field. It’s not a long exposure. We haven’t even really tried to use this telescope to look at a place in a long time.” This is just the beginning!