Bibcode
Barrena, R.; Ramella, M.; Boschin, W.; Nonino, M.; Biviano, A.; Mediavilla, E.
Bibliographical reference
Astronomy and Astrophysics, Volume 444, Issue 3, December IV 2005, pp.685-695
Advertised on:
12
2005
Journal
Citations
10
Refereed citations
9
Description
We continue the development of our Voronoi Galaxy Cluster Finder (VGCF)
technique by applying it to galaxy catalogs obtained with B and R band
observations of four high galactic latitude fields of 0.5 × 0.5
square degrees each. These fields are deep (Rlim ˜ 23,
Blim ˜ 26) and partially overlap the Palomar Distant
Cluster {Survey} (PDCS) fields at 0h and 2h. We
run the VGCF also on the original V and I band PDCS galaxy catalogs. We
identify a total of 48 clusters that are particularly reliable, being
detected in at least two bands. The analysis of color-magnitude diagrams
and, in a few cases, spectroscopic observations allow us to further
increase the reliability of 25 of the 48 clusters. For these 26 clusters
we also estimate redshifts that fall in the approximate range 0.2 < z
< 0.6. We detect 41 VGCF clusters within the strict limits of the
PDCS fields at 0h and 2h. The PDCS catalog for the
same regions consists of 28 clusters. The two catalogs have 20 clusters
in common. These clusters together with the remaining PDCS and VGCF
clusters lead to a total number of 46 "independent" clusters. The total
number of clusters is therefore 20% larger than the number of VGCF
clusters and more than 60% larger than the number of PDCS clusters.
These results confirm a) that the VGCF is a competitive algorithm for
the identification of optical clusters, and b) that a combined catalog
of matched-filter and VGCF clusters constitutes a significant progress
toward a more complete selection of clusters from bidimensional optical
data.