An analysis of R ≥ 1 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 the studied Abell cluster datasets is not present in our samples. There are, however, indications of residual anisotropies which we show are the result of two elongated superclusters, Ursa Majoris and Corona Borealis whose axes lie near the line-of-sight. After rotating these superclusters so that their semi-major axes are perpendicular to the line-of-sight, we find no indication of anisotropy in ξ(σ, π). The amplitude and slope of the correlation function remain the same before and after these rotations. We also remove a subset of R = 1 Abell/ACO clusters that show sizeable foreground/background galaxy contamination and again find no change in the amplitude or slope of the correlation function. We conclude that the correlation length of R ≥ 1 Abell clusters is not artificially enhanced by line-of-sight anisotropies.

The results of spectroscopic observations of 46 R º 1 clusters of galaxies from the Abell and Abell, Corwin, & Olowin (hereafter ACO) catalogs are presented. The observations were conducted at the ESO 3.6 m telescope with the Meudon-ESO Fibre Optics Spectrograph (MEFOS) multiple-Ðber spectrograph. Thirty-nine of the clusters lie in a 10¡ ] 45¡ strip of sky that contains two supercluster candidates (in Aquarius and Eridanus). These candidates were identiÐed by a percolation analysis of the Abell and ACO catalogs, using estimated redshifts for clusters that had not yet been measured. With our measurements and redshifts from the literature, the target strip is now 85% complete in redshift measurements for R º 1 ACO clusters with Seven other clusters were observed in a supercluster candidate m 10 ¹ 18.3. in the Grus-Indus region. Seven hundred thirty-seven galaxy redshifts were obtained in these 46 cluster Ðelds. We Ðnd that one of the supercluster candidates is a collection of 14 R º 1 ACO/Abell clusters with a spatial number density that is 20 times the average spatial density for rich ACO clusters. This overdensity has a maximum extent of D110 h~1 Mpc, making it the longest supercluster composed only of R º 1 clusters to be identiÐed to date. This Ðlament of clusters runs within 6¡ of the line of sight in the Aquarius region, and, on its high-z end, four R \ 0 ACO clusters (three of which are R \ 1 in the Abell catalog) appear to bridge gaps to other clusters, extending the structure to D150 h~1 Mpc. Our analysis also reveals that another supercluster, consisting of eight rich clusters with an extent of D75 h~1 Mpc, runs roughly perpendicular to Aquarius near its low-redshift end. Both of these superclusters are remarkably Ðlamentary. Fitting ellipsoids to all N º 5 clumps of clusters (at b \ 25 h~1 Mpc) in the measured-z Abell/ACO R º 1 clusters sample, we found two other superclusters with axis ratios º3 (long-to-midlength axis). The frequency of such Ðlaments (D20%) was nearly identical with that found among "" superclusters ÏÏ in Monte Carlo simulations of random and random-clumped cluster samples, however, so the Abell/ACO clusters have no particular tendency toward Ðlamentation. The Aquarius and Aquarius-Cetus superclusters, in this one region of the sky, have axis ratios of 4.3 and 3.0, respectively. The Aquarius Ðlament also contains a "" knot ÏÏ of six R º 1 clusters at z D 0.11, with Ðve of the clusters close enough together to represent an apparent overdensity of 150There are three other n6 . R º 1 cluster density enhancements similar to this knot at lower redshifts : Corona Borealis, the Shapley concentration, and another grouping of seven clusters in Microscopium. All four of these dense superclusters appear near the point of breaking away from the Hubble Ñow, and some may now be in collapse, but there is little indication of any being virialized. With four such objects, studies of them as a class may now lead to much greater insight into large-scale processes.

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We have used the MX multifiber spectrometer on the Steward 2.3m measuring redshifts of up to 25 galaxies in each of about 90 Abell cluster fields with richness class R ≥ 1 and mag10 ≤ 16.8 (estimated z ≤ 0.12) and no more than one previously-measured redshift. This work has resulted in a deeper, more complete sample for two-point correlation and other studies of large-scale structure. To date, we have collected such data for 110 clusters (a few not in our sample). For most, we have seven or more cluster members with redshifts, enough to add significantly to the available sample of cluster velocity dispersions for other studies of cluster properties.