The Pisces-Cetus supercluster: a remarkable filament of galaxies in the 2dF Galaxy Redshift and Sloan Digital Sky surveys

The Pisces-Cetus supercluster (redshift z∼ 0.06) is one of the richest nearby (z < 0.1) superclusters of galaxies, and emerges as a remarkable filament of galaxies at the edges of the two-degree Field Galaxy Redshift Survey (2dFGRS) and the ongoing Sloan Digital Sky Survey (SDSS). We explore the extent of the supercluster on the sky and in redshift space, and map the distribution of its constituent clusters and groups. We find evidence of enhanced star formation in galaxies belonging to groups in the supercluster compared to those in the field. This effect appears to be higher among the poorer groups than in the richer ones. In contrast, star formation is suppressed in the galaxies in rich clusters, which is consistent with previous studies. We identify two major filaments in this supercluster, consisting of 11 and 5 Abell clusters, including Abell 133 and Abell 85, respectively, and estimate the virial masses of the clusters from their velocity dispersions and optical surface brightness profiles. The lower limit to the masses of these filaments, amounting to the total virial mass of the constituent clusters, turns out to be 5.2 × 1015 h−170 M⊙ and 6.0 × 1015 h−170 M⊙ over volumes of almost 6750 h−370 Mpc3 and 19 600 h−370 Mpc3, respectively. This corresponds to mass overdensities of Ω/Ωcrit=δM > 4.7 and δM > 1.3 for the two filaments making up the supercluster.