Detection of candidate primordial galaxies at z>4

Abstract

We report on the detection of four primordial galaxies candidates in the redshift range 4.55 < z < 4.76, as well as 4 other candidates in the range 4.12 < z < 4.32. These galaxies have been detected with the now common technique of the Lyman break, but with a very original instrumental setup, which allows the simultaneous detection on a single exposure of three narrow (FWHM ~ 200 A) bands. Depending on between which pair of bands the Lyman break is located, it thus allows to detect two ranges of redshifts. Two of the the higher redshift candidates are located only 50 kpc apart, thus forming a possible primordial galaxy pair.