Webb Spectra Reach New Milestone in Redshift Frontier

The JWST Advanced Deep Extragalactic Survey (JADES) focused on the area in and around the Hubble Space Telescope’s Ultra Deep Field. Using Webb’s NIRCam instrument, scientists observed the field in nine different infrared wavelength ranges. From these images (shown at left), the team searched for faint galaxies that are visible in the infrared but whose spectra abruptly cut off at a critical wavelength known as the Lyman break. Webb’s NIRSpec instrument then yielded a precise measurement of each galaxy’s redshift (shown at right). Four of the galaxies studied are particularly special, as they were revealed to be at an unprecedentedly early epoch. These galaxies date back to less than 400 million years after the big bang, when the universe was only 2% of its current age.

In the background image blue represents light at 1.15 microns (115W), green is 2.0 microns (200W), and red is 4.44 microns (444W). In the cutout images blue is a combination of 0.9 and 1.15 microns (090W+115W), green is 1.5 and 2.0 microns (150W+200W), and red is 2.0, 2.77, and 4.44 microns (200W+277W+444W).

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