Astronomers find the most distant known galaxies

A mosaic of six distant galaxies located by gravitational lensing. Each image, taken with the NIRSPEC instrument on Keck II, reveals a faint spectrum line (circled) in the infrared spectral region which the astronomers interpret as arising from a line of neutral hydrogen, significantly `redshifted' from its normal location in the ultraviolet. The team has invested significant amounts of observing time to eliminate the possibility that each faint line arises from a different atomic species, for example as would be the case if the galaxies were at less extreme distances. Image credit: Caltech