Deprojected velocities for the observed pairs (grey) and mock-observed simulation without (blue), with (red), and with doubled (turquoise) velocity errors. The light-red histogram in the background shows the v_3D intervelocity distribution for the full sample, as determined from the peculiar velocity difference of the galaxy pairs using the available full phase-space information of the simulation. Also shown are the two-Gaussian model fits to the histograms used to determine the positions of the velocity peak. The peak position and its 1σ-uncertainty are indicated by solid lines at the bottom of the figure.