Three spectra of galaxies in the cluster RXJ0152.7-1357

Three spectra of galaxies in the cluster RXJ0152.7-1357 from GMOS-North are shown here. The top spectrum is of the brightest galaxy in the cluster (id=766). This galaxy has a spectrum typical of an old stellar population with no recent star formation. The middle spectrum (id=566) is one of a handful of galaxies that show very weak star formation and an abundance of young stars together with older stars. The weak emission line marked [OII] shows the presence of star formation, while the strong Balmer absorption Hδ and Hγ show the young stars. The bottom spectrum (id=896) is typical of a spiral galaxy with strong star formation and therefore has a very strong [OII] emission line. Black lines represent galaxy spectra. Green lines represent spectra noise multiplied by 4.