Diagrama color-magnitud en grupos de galaxias a "redshifts" intermedios

J. L. NILO CASTELLON, M. V. ALONSO, H. CUEVAS, D. G. LAMBAS, A. RAMIREZ

San Juan

Conferencia; AAA51; 2008

Observatorio OAFA

This is a report with the first results of the photometric analysis of two low  luminosity X-ray clusters:  RXJ1117.4+0743 and  RXJ1252.0+2920, selected from the 160 Square Degree ROSAT Cluster Survey (Vikhlinin et al. 1998). This work is part of an ongoing project to study the cluster properties and the galaxy population of poor clusters in the redshift range of 0.1 $<$ z $<$ 0.5.  Preliminary results show that, while RXJ1117.4+0743 is probably  in the assembly period, the cluster RXJ1252.0+2920 would be in a more evolutionary stage.