A New Measurement of the Spectral Lag of Gamma-Ray Bursts and its Implications for Spectral Evolution Behaviors [HEAP]

http://arxiv.org/abs/1610.07191


We carry out a systematical study of the spectral lag properties of 50 single-pulsed Gamma-Ray Bursts (GRBs) detected by Fermi/GBM. By dividing the light curves into multiple consecutive energy channels we provide a new measurement of the spectral lag which is independent on energy channel selections. We perform a detailed statistical study of our new measurements. We find two similar universal correlations by investigating the correlations between the photon arrival time versus energy and pulse width versus energy, respectively. We also study the spectral evolution behaviors of the GRB pulses and most of them follow neither “hard-to-soft” (HTS) nor “hardness-intensity tracking” (HIT) trends. We find that a GRB pulse with negligible spectral lag would appear to have an HIT behavior and a GRB pulse with significant spectral lag would appear to have an HTS behavior. The HTS might not be a genuinely true behavior.

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L. Shao, B. Zhang, F. Wang, et. al.
Tue, 25 Oct 16
38/69

Comments: 41 pages, 6 figures, submitted to ApJ