Centre and maximum velocities of the two components in the Hα contrast profiles of the three active spectra in CME candidate 1. Panel A presents the centre velocities of the components shown by the dashed green lines in Fig. 4, and panel B shows the corresponding maximum velocities. Panel C presents the centre velocities of the components shown by the dashed blue lines in Fig. 4, and panel D shows the corresponding maximum velocities. The error bars represent the double Gaussian fitting errors.