5.3. Large Scale Voids in space (~ 100 to 200 Mpc)
There exists a substantial decrease of galaxies toward the center of the Bootes Void, and an increase of galaxies in a shell around the Void, with a total Void diameter of 120 Mpc. The Bootes Void (center and shell) was searched for any excess magnetic effects, over the large scale background to the left and right. No excess rotation measure (< 10 rad/m2) was found, implying a shell magnetic field to < 0.1 µGauss for the ordered component (Vallée, 1991a).