Published online by Cambridge University Press: 25 May 2016
There are evidenves which suggest that many of the early-type galaxies in rich cluster environment formed at fairly high redshift, z > 2. If the galaxies formed at such early epoch have experienced no intensive star-formation events, their photometric properties can be traced with less ambiguity by using the stellar evolutionary sinthesis models. Here we demonstrate what conspicuous feature can be observed for those passively-evolving galaxies at high redshift and how we can constrain the epoch and period of their formation.