ImpZ: a new photometric redshift code for galaxies and quasars

We present a combined galaxy-quasar approach to template-fitting photometric redshift techniques and show the method to be a powerful one. The code, ImpZ, is presented, developed and applied to two spectroscopic redshift catalogues, namely the Isaac Newton Telescope Wide Angle Survey ELAIS N1 and N2 fields and the Chandra Deep Field North. In particular, optical size information is used to improve the redshift determination. The success of the code is shown to be – – – – –