Are the Perseus-Pisces chain and the Pavo-Indus wall connected?

Abstract

In this paper we present a new redshift survey undertaken to address the rather interesting question that arises when all the currently available redshift information from the LEDA data base is plotted in 'hypergalactic' coordinates. A significant empty region was found between the southern Pavo-Indus (PI) wall and the northern Perseus-Pisces (PP) chain. This survey tests the reality of this void which may simply reflect previously poor sampling of the galaxies in this region. Redshifts for a magnitude-selected sample of 379 galaxies were obtained covering the four UKST/SERC survey fields: #537, #470, #346 and #290 with 15.5 ≤ BT ≤ 17.0 mag. All redshifts were obtained with the FLAIR multi-object spectroscopy system on the 1.2-m UK Schmidt Telescope at Siding Spring, Australia. Two highly significant density enhancements were found in the galaxy distribution at 133 and 200 Mpc (H0 = 75 km s-1 Mpc-1). We claim that no connection exists between PP and PI. However, a southern extension of PP was detected and makes the total length of this chain more than 150 Mpc.