Correlation coefficients between CMB maps and the galaxy distribution map for low multipoles. Histogram shows correlation coefficients between the galaxy distribution map and simulated CMB maps, vertical line shows the same using the Planck CMB map. Clockwise from the upper left plot we show the correlation results with upper multipoles ℓ_max = 5, ℓ_max = 7, ℓ_max = 10 and ℓ_max = 16. The number in brackets show the number of simulations with a higher correlation coefficient than the data.