NASA JWST has given us a picture of older candidate galaxies that the Hubble telescope couldn’t see previously.
The JWST, or James Webb Space Telescope, has been giving us a great look into the cosmos ever since it went up last year. After a stunning bunch of pictures last year that stunned the internet, JWST has now given a team of scientists the first glimpse into what could be a bunch of the first galaxies that were created after the Big Bang. Astronomer Haojing Yan from the University of Missouri published a new study that catalogues 87 galaxies in the universe that could date back to almost 13.6 billion years ago. That would be just 200 million years after the Big Bang.
“This is the first large sample of candidate galaxies beyond the reach of the Hubble Space Telescope,” said Haojing Yan at a press conference at the American Astronomical Society meeting in Seattle. The birthdates of these galaxies are yet to be confirmed, which is why they are termed as candidate galaxies. If confirmed, we could be looking at the earliest galaxies that the universe created, although we won’t know if those galaxies are still alive and in what form.
JWST finds oldest galaxies of universe
Although scientists have been studying several older galaxies that were discovered previously, Yan’s report could give his team the chance to break a record since these galaxies could be closer to the Big Bang’s date.
Finding the birthdate of these galaxies could be a big challenge. Scientists will need to measure its redshift, a technique that calculates how much light it emits is stretched towards the longer red wavelengths. This tells astronomers how fast the galaxy is moving away from us, thereby telling us the distance in the process. This could help scientists determine the time for the light to reach us, which is currently expected to be 13.6 billion years ago.
Yan’s team used the JWST’s NIRCam at six near infrared wavelengths. The 87 candidate galaxies mostly look like light blobs and can only be detected in the longer near-infrared wavelengths. This suggests there are very far away and very old.
The NIRCam on the JWST could help others to determine the shape of these older galaxies, something which the Hubble telescope struggled with. “The increased resolution of JWST allows us to see the structure more clearly, and the high sensitivity of the NIRCam instrument allows us to see faint features that we just couldn’t see before,” says Jeyhan Kartaltepe, an astrophysicist at the Rochester Institute of Technology who’s part of the Cosmic Evolution Early Release Science survey.