Large groups in the Chile-UK quasar survey

Abstract

The Chile-UK quasar survey, a new-generation 140 deg^2 UVX survey to B = 20, is now \sim 25 per cent complete. The catalogue currently contains 319 quasars and 93 emission line galaxies. Using the minimal-spanning tree method, we have independently confirmed the \sim 200 h^-1 Mpc group of quasars at z \simeq 1.3 discovered by Clowes & Campusano (1991). We have discovered a new \sim 150 h^-1 Mpc group of 13 quasars at median z \simeq 1.51. The null hypothesis of a uniform, random distribution is rejected at a level of significance of 0.003 for both groups.