The formation and assembly of a typical star-forming galaxy at redshift z approximately 3 Recent studies of galaxies approx23 Gyr after the Big Bang have revealed large, rotating disks, similar to those of galaxies today1, 2. The existence of well-ordered rotation in galaxies during this peak epoch of cosmic star formation indicates that gas accretion is likely to be the dominant mode by which galaxies grow, because major mergers of galaxies would completely disrupt the observed velocity fields.
LBG J2135-0102 (also known as the "Cosmic Eye" due to its morphological similarity to the Egyptian "Eye of Horus") was discovered from a Hubble Space Telescope (HST) image in an effort to survey high redshift galaxy clusters. This galaxy is a typical star-forming galaxy at z=3 (seen when the Universe was only two billion years old) which has been gravitationally lensed by a factor 28x by a foreground galaxy cluster. The discovery paper can be found in Smail et al. (2007) ApJL 654 33 , whilst the detailed lens modelling used to correct for the lensing distortion is available in Dye et al. (2007) MNRAS 379 308.