Underlying global features of the X-ray light curves of Swift gamma-ray bursts

Abstract

With its rapid response, Swift has revealed plenty of unexpected properties of gamma-ray bursts (GRBs). With an abundance of observations, our current understanding is only limited by the complexity of early X-ray light curves. In this work, based on the public Swift data of 150 well-monitored GRBs with measured redshifts, we find some interesting global features in the rest-frame X-ray light curves. The distinct spectral behaviors between the prompt emission and the afterglow emission imply dissimilar radiation scenarios. Interestingly, an unforeseen plateau is exhibited in the prompt X-ray light curves despite the presence of complex spikes, which might indicate the presence of a steady central engine. In particular, the seemingly continuous evolution with a single power law from the prompt to the afterglow of most GRBs might place strong constraints on the theoretical models. © 2010. The American Astronomical Society. All rights reserved.