A comprehensive comparative study of temporal properties between X-ray flares and GRB pulses
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We demonstrate that the optical flares, X-ray flares (XRFs), and the gamma-ray burst (GRB) pulses exhibit similar behaviors as evidenced by correlations among temporal properties and the temporal properties on energy by a comprehensive comparative analysis of 24 optical flares, 92 XRFs and 102 GRB pulses. The flare/pulse peak time, t pk , is correlated with their width, w, and with w/t pk for the three samples, but their slopes are very different. Both of the flares and GRB pulses bear the similar asymmetries and the asymmetry evolves neither with w nor with t pk . The spectral lags of the XRFs are much larger than those of the GRB pulses and almost follow the same lag versus width relation as that of the GRB pulse. In addition, the corresponding broadening of temporal properties (width, rise width and decay width) of the XRFs with energy decreasing follows the same power-law relation as those of the GRB pulses. The K-S tests show the distributions of the three corresponding power-law indices of the XRFs are the same as those of the GRB pulses at the 1 % significance level. All of our demonstrated relations and previous correlated relations seem to indicate that the XRFs as well as the optical flares should be belong to a extended class of the prompt GRBs that dominate the tail of the distribution function. Therefore, our analysis results place some constraints on the physical mechanism responsible for the pulsed emission properties.
KeywordsGamma rays: bursts Method: statistical
We acknowledge the anonymous referee for careful and helpful review. We thank Xiaohong Zhao for helpful discussions. This work was supported by the National Natural Science Foundation of China (grant 11263006), the Key Program for Science Fund of the Education Department of Yunnan Province (2011Z004), the Open Research Program of Key Laboratory for the Structure and Evolution of Celestial Objects (OP201106), the High-Energy Astrophysics Science and Technology Innovation Team of Yunnan Higher School and the Yunnan Gravitation Theory Innovation Team (2011C1).