The consistency of the Rapid Decay Phase of GRBs with High Latitude Emission
The rapid decay phase (RDP) of gamma-ray bursts (GRBs) has been shown to be a smooth temporal and spectral continuation of the prompt emission, strongly suggesting it is its tail. The most popular model to explain it is the high latitude emission (HLE) model, in which when the emission stops photons from increasingly larger angle from the line of sight still reach the observer. Several authors have studied the consistency of the RDP with this model, but often with simplifying assumptions that made the result uncertain. It is very important to know if the RDP can be explained by HLE, since that would allow us to distinguish between models for the prompt emission that give rise to HLE, like the popular internal shocks model, or those who do not, like magnetic reconnection in a Poynting flux dominated outflow. I will describe the physically motivated model we developed, then results from fitting this model to a set of data. I will insist on the particular case of short bursts with extended emission, and show that their RDP behave differently. I will conclude that the HLE is a valid explanation for the RDP, even if another mechanism may be at work for burst with extended emission.