Fig. 3.
An analysed IceTop-IceCube coincidence event from 7 February. The main graph shows the optical module depth in metres versus the arrival time of the first photon. The insets show the hits in the IceTop tanks and the waveform observed at the top optical module. The two fitted lines show the fit dz/dt for the muon, both for the in-ice digital optical modules only ("IceCube") and including the IceTop hits ("combined").