Abstract
High redshift clusters of galaxies are amongst the largest cosmic structures. Their properties and evolution are key ingredients to our understanding of cosmology. However, not much is yet known about the properties of clusters at redshifts of cosmological interest. We propose here a radically new method for studying large samples of cluster galaxies using microslits to perform spectroscopy of huge numbers of objects in single fields in a narrow spectral range--chosen to fit an emission line at the cluster redshift. Our objective is to obtain spectroscopy in a very restricted wavelength range ( ≈ 100 Å in width) of several thousands of objects for each single 8 × 8 square arcmin field. Approximately 100 of them will be identified as cluster emission line objects and will yield basic measurements of the dynamics and star formation in the cluster (that figure applies to a cluster at z ≈ 0.50, and becomes ≈ 40 and ≈ 20 for clusters at z ≈ 0.75 and z ≈ 1.00 respectively). This is a pioneering approach that, once proven, will be followed in combination with photometric redshift techniques and applied to other astrophysical problems.
