**AAS Meeting #193 - Austin, Texas, January 1999**

*Session 39. Cosmology/Large Scale Structure*

Display, Thursday, January 7, 1999, 9:20am-6:30pm, Exhibits Hall 1
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## [39.10] Discovery of Two Highly Extended, Filamentary Superclusters in Aquarius

*D. Batuski, C. Miller, K. Slinglend (U. Maine), C. Balkowski, S. Maurogordato, V. Cayatte, P. Felenbok (Obs. de Paris, Meudon), R. Olowin (St. Mary's College, CA)*

We conducted percolation analyses of a sample of all R \ge
1 Abell/ACO clusters with measured redshifts, including
results from two of our own recent redshift surveys, which
provided 200 cluster redshifts based on multiple-galaxy
observations. With a percolation parameter b = 25 h^{-1}
Mpc (spatial number density n = 8\bar{n}), the Aquarius
supercluster of Miller *et al.* 1998 (**BAAS, 28**,
1289) appears as a collection of 14 R \ge 1 clusters with
a maximum extent of ~110 h^{-1} Mpc, the longest such
supercluster identified to date. This filament of clusters
runs within 7^{\circ} of the line of sight.

Our analysis also reveals that another supercluster,
Aquarius-Cetus, consisting of eight rich clusters with an
extent of ~75 h^{-1} Mpc, runs roughly perpendicular
to Aquarius near its low-redshift end.

Both of these superclusters are remarkably filamentary.
Fitting ellipsoids to all N \ge 5 clumps of clusters (at
b = 25 h^{-1} Mpc) in the measured-z Abell/ACO R \ge 1
clusters sample, we found no significant tendency toward
filamentation (axis ratio \ge 3) in comparison with
`superclusters' in Monte Carlo simulations of random and
random-clumped cluster samples. Yet Aquarius and
Aquarius-Cetus, in this one region of the sky, have axis
ratios of 4.3 and 3.0, respectively.

The Aquarius filament also contains a `knot' of six R \ge
1 clusters at z ~0.11, with five of the clusters
close enough together to represent an apparent overdensity
of 150 \bar{n}. There are three other R \ge 1 cluster
density enhancements similar to this knot at lower
redshifts: Corona Borealis, the Shapley Concentration, and
another grouping of seven clusters that we found in
Microscopium. These four superclusters appear near the point
of breaking away from the Hubble Flow, and may even 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
phenomena.

The author(s) of this abstract have provided an email address
for comments about the abstract:
batuski@maine.edu

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