Astron. Astrophys. 345, 363-368 (1999)

4. Conclusions

In this paper 19 additional cluster candidates detected in EIS patch B have been presented. Cluster candidates have also been identified using the V-band galaxy catalogs available for patches A and B. The analysis of the cross-identification of the V- and I-band detections, as summarized in Table 3, leads to the following general conclusions:

1. About 95% of the cluster candidates with and about 30% with , primarily rich clusters, are confirmed using the V-band data. This result provides confidence about the reality of the cluster candidates detected in the areas where only I-band data are available.

2. About 80% of the low redshift () candidates show a suggestion of the CM relation expected for early-type galaxies in clusters. This detection serves as an independent confirmation of the candidate clusters. It also provides an independent redshift estimate, which is in general consistent with the estimates from the matched filter method.

3. The well-defined CM relations provide the possibility of selecting individual galaxies for follow-up spectroscopy to measure more accurate redshifts and velocity dispersions.

Unfortunately, the band data are not deep enough to use the CM relation to gain leverage for candidates at . For future surveys using wide-field cameras, such as the Pilot Survey (Renzini 1998) to be conducted at the ESO 2.2m telescope, the option of doing significantly deeper band observations should therefore be considered.

Table 3. Summary of the cross-identification rates.

© European Southern Observatory (ESO) 1999

Online publication: April 19, 1999
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