The distant radiogalaxies recently discovered at the most remote distances (z≥3.5) are among the best cosmological targets. However so various features caracterize these galaxies (red stellar energy distribution, huge emission lines, high density of galaxy companions, alignment of ultraviolet and radio axes, large degree of polarisation) that their structures are not simple to understand. Stellar populations will only become the best indicators of evolution of galaxies if these structures are clearly understood from a two-dimension spectroscopy on each image point. The integral field spectrograph TIGER is a unique instrument at the CFHT to give details on the nature and velocities of the various components of distant radiogalaxies.We present the observations with TIGER of an intermediate-redshift galaxy 3C435A (z=0.471) (Rocca-Volmerange et al, 1994). The two nebular lines [OII], [OIII] and the largely extended stellar continua are observable, allowing to date galaxy with the help of our evolution model. The present and past star formation activities and the origin of alignment will be thus analysed in terms of galaxy evolution.
The Northern Sky Optical Cluster Survey. IV. An Intermediate-Redshift Galaxy Cluster Catalog and the Comparison of Two Detection Algorithms