Weighing the largest mass concentrations in the Great Attractor region

We propose XMM observations of 10 galaxy clusters at z<0.075 , located within a 40\\times 40 deg ^2 region around the approximate location of the Great Attractor (GA), to explain the observed largescale flow toward and beyond the GA. All targets were found in the course of the CIZA Xray cluster survey, 9 of them are new discoveries. Our total sample of 12, which also includes A3627 andTriangulum Australis, represents a complete census of the most Xray luminous and thus likely most massive clusters in this region. The proposed observations will allow us to measure accurate cluster masses, which in turn will permit a reconstruction of the local gravitational field that is independent of and complementary to the one based on the density of IRASselected field galaxies. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]