James Webb Space Telescope Discovers Oldest Known Galaxies

A group of international astronomers have used data from the James Webb Space Telescope to report the discovery of the first confirmed galaxies to date.

In work, which NASA says has yet to be peer-reviewed, scientists found that light from these galaxies took more than 13.4 billion years to reach Earth, as the galaxies date back less than 400 million years after the Big Bang.

Previous Webb data had provided candidates for nascent galaxies and the targets were confirmed by obtaining spectroscopic observations.

These observations revealed characteristic and distinctive patterns in the light emitted by faint galaxies.

Using observations from the JWST Advanced Deep Extragalactic Survey (JADES) program, the observations focused on the area in and around the ultra-deep field of the Hubble Space Telescope.

Starting with the telescope’s near infrared camera, or NIRCam, the JADES program used more than 10 days of mission time to observe the field in nine different infrared colors.

In the images, the youngest galaxies are distinguished by the light stretched in wavelength up to a factor of 14.

Using observations from the JWST Advanced Deep Extragalactic Survey (JADES) program, the observations focused on the area in and around the ultra-deep field of the Hubble Space Telescope.

Starting with the telescope’s near infrared camera, or NIRCam, the JADES program used more than 10 days of mission time to observe the field in nine different infrared colors.

In picturesthe youngest galaxies are distinguished by light stretched in wavelength up to a factor of 14.

NASA said astronomers are looking for faint galaxies that are visible in the infrared but whose light abruptly cuts off at a critical wavelength.

The agency noted that the location of the cutoff in each galaxy’s spectrum is shifted by the expansion of the universe.

Then, using the Near Infrared Spectrograph instrument for three days, the team collected light from 250 faint galaxies, with a study of the patterns on the spectrum by the atoms of each galaxy, which allowed to accurately measure the redshift of each galaxy and reveal the properties of gas and stars in these galaxies.

Four of the galaxies were found to be unprecedentedly early, being at redshifts greater than 10, or when the universe was around 330 million years old.

“For the first time, we have discovered galaxies only 350 million years after the Big Bang, and we can be absolutely sure of their fantastic distances,” co-author Brant Robertson, of the University of California, Santa Cruz and member of the NIRCam science team, said. “Finding these first galaxies in images of such breathtaking beauty is a special experience.”

Next year, JADES will continue the detailed study of another field, this one centered on the iconic Hubble Deep Field.