first galaxies

First galaxies are targets of some searches, e.g., Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS), typically searching in near infrared. The goal is to find ancient galaxies with ever higher redshifts, and with little or no metal. Candidates are in the z=7-to-12 range. Deep photometric survey images are scanned, e.g., for dropouts in the images taken through the shorter-wavelength filters. JWST is basically tailored to find and study such galaxies: an early program is JADES, which is finding candidates, including some with photometric redshifts of z beyond 12. Observation has overtaken theory since galaxy formation theories don't create galaxies as soon after the Big Bang as observation is revealing.