input $E_{\rm peak}$ energy within the 1$\sigma$ confidence interval of the fits. The simulations were performed over a grid of amplitude, alpha, beta, and $E_{\rm peak}$ values and the plot marginalizes over all parameters except $E_{\rm peak}$. The orange region denotes the GBM energy range. \[EpeakRecover\]](EpeakRecover.pdf)

Hard-to-soft [$E_{\rm peak}$]{} Evolution in Pulses
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Recent work has firmly established that pulses, defined as an emission episode with a rise in brightness to a peak followed by a decay, are the prime building blocks that make up the prompt emission light curve in GRBs [@HakkilaCumbee]. One piece of evidence supporting this conclusion is the observation of temporal evolution of [$E_{\rm peak}$]{} throughout many bright, isolated pulses. In the hard-to-soft (HTS) case, [$E_{\rm peak}$]{} evolves smoothly (in many cases as a power law) from an initial high value at the onset of the pulse, through the rising portion, the peak and the decaying portion to a final low energy when the pulse can no longer be detected [@lu10; @NorrisCat; @axelsson; @preece2014; @burgess14]. Another behavior, called hardness-intensity ‘tracking’ (HIT), is where the fitted value of [$E_{\rm peak}$]{} follows the pulse intensity (expressed as integrated counts over a standard energy range) with good correlation. @HakkilaPreece 