text: FIG. 2: Crab light curve. Horizontal scale is in modiﬁed 
  Julian days over the 490 day GBM exposure period. Ver- 
  tical scale is in photons/cm2/sec/keV averaged over daily 
  intervals. Horizontal lines show the average ﬂux in each of 
  ﬁve energy bands increasing from top to bottom 