2D histograms of combinations of parameters from power-law fits used to characterize the shape of the power spectra for the full sample; all galaxy setups, observer position and sky fractions merged together. Panel a: from top left to bottom right we have , (α^EE, α^BB), and . The main diagonals are shown in top panels for reference. In the bottom panels the horizontal lines mark values of and the vertical lines show the median of the spectral indices. Panel b: versus . The horizontal and vertical lines mark ratio values of 1 and 2 and are given for visual reference. The main diagonal is also shown.