Figure 1: The signal from one of the LIGO detectors in Hanford, Washington, is shown with two representations of the best-fit numerical relativity (NR) waveform. The filtered NR waveform illustrates how the raw waveform is perceived by the detector, showing that for GW150914 the instrument was most sensitive to the late-inspiral, merger, and ringdown of the event (data and analysis scripts from Ref.[9]).