Bivariate distributions of measured properties from the global H I profiles of the H I detected sources. Peak flux density (a) and integrated flux density (b) as a function of W₂₀ line width, derived from the global H I profiles. The detection thresholds based on the three velocity smoothing kernels used for the source-finding are represented by the black lines in Fig. 10b. The colours of the data points represent the over-density to which the galaxy belongs: A2626 sources are green, The Swarm sources are orange, A2637 sources are pink, and the sources coloured blue belong to the Perseus-Pegasus filament. Grey data points are galaxies in the volume that do not belong to a spectral over-density. The histograms along the top and right side of the panels show the 1D distribution of the observable along that axis.