AAS Meeting #193 - Austin, Texas, January 1999
Session 92. Clusters of Galaxies
Oral, Friday, January 8, 1999, 2:00-3:30pm, Room 9 (A and B)

[Previous] | [Session 92] | [Next]

[92.01] Projection, Correlation, and Anisotropy in the Abell Catalog

C. Miller, K. Slinglend, D. Batuski (UMaine), J. M. Hill (Steward Obs.)

An analysis of R > 0 Abell clusters is presented for samples containing recent redshifts from the MX Northern Abell Cluster Survey. The newly obtained redshifts from the MX Survey, as well as those from the ESO Nearby Abell Cluster Survey (ENACS), provide the necessary data for spatial analyses of the largest (in number and in volume) sample of rich clusters in the entire sky (excluding the galactic plane). The MX Survey, undertaken primarily to provide data for large-scale structure studies, has also provided a large compilation of galaxy redshifts within Abell cluster fields for the examination of projection effects. We determine the two-point spatial correlation function and also examine previously suggested anisotropies within the Abell catalog. Specifically, we utilize three subsets of the Abell/ACO catalogs: (1) all Northern Hemisphere R > 0 Abell clusters with m10 <= 16.8 (Ncl = 198). (2) all measured Northern Hemisphere cD Abell clusters within 300h-1Mpc (Ncl = 104); (3) all Southern and Northern Hemisphere R > 0 Abell/ACO clusters with m10 <= 16.8 (Ncl = 284).

We examine the sample for contamination due to projection effects and find that single-galaxy cluster redshifts produce erroneous results (> 2000 km s-1) 14% of the time. An analysis of the cluster galaxy populations show that the richness levels assigned to the Abell clusters are roughly consistent with the estimates originally made by Abell (1958). After excluding R = 0 clusters, we show that specific superclusters elongated along the line-of-sight, contribute entirely to the remaining anisotropy within the Abell catalog. We conclude that the R \ge 1 subset of Abell/ACO clusters provides a large dataset that is substantially free of projection contamination, as long as multiple-galaxy cluster redshift observations are made.

[Previous] | [Session 92] | [Next]