Exploring the canonical behaviour of long gamma-ray bursts using an intrinsic multi-wavelength afterglow correlation

In this paper we further investigate the relationship, reported by Oates et al., 2012, between the optical/UV afterglow luminosity (measured at restframe 200s) and average afterglow decay rate (measured from restframe 200s onwards) of long duration Gamma-ray Bursts (GRBs). We extend the analysis by examining the X-ray light curves, finding a consistent correlation. We therefore explore how the parameters of these correlations relate to the prompt emission phase and, using a Monte Carlo simulation, explore whether these correlations are consistent with predictions of the standard afterglow model. We find significant correlations between: $\mathrm{l}\mathrm{o}\mathrm{g}{\mathrm{L}}_{\mathrm{O},200\mathrm{s}}$ and $\rm log;L_{X,200\rm{s}}$;$\alpha_{O,>200\rm{s}}$and$\alpha_{X,>200\rm{s}}$, consistent with simulations. The model also predicts relationships between $\rm log;E_{iso}$and$\rm log;L_{200\rm{s}}$, however, while we find such relationships in the observed sample, the slope of the linear regression is shallower than that simulated and inconsistent at $\gtrsim 3\sigma$. Simulations also do not agree with correlations observed between $\rm log;L_{200\rm{s}}$and$\alpha_{>200\rm{s}}$,or$\rm log;E_{iso}$and$\alpha_{>200\rm{s}}$. Overall, these observed correlations are consistent with a common underlying physical mechanism producing GRBs and their afterglows regardless of their detailed temporal behaviour. However, a basic afterglow model has difficulty explaining all the observed correlations. This leads us to briefly discuss alternative more complex models.