Light Curve Characteristic of Gamma-Ray Burst
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Date
2024-03
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Addis Ababa University
Abstract
The long-lasting afterglow emissions, which shift from a higher energy X-ray band to a lower energy radio band, are produced by the interaction between the relativistic jet and the surrounding medium. Our understanding of afterglow, both theoretically and observationally, was fundamentally altered with the launch of the Swift satellite.
One of Swift’s observational findings was the identification of an X-ray afterglow’s canonical behavior, in which the light curves generally comprise four different
power law segments: initial steep decay, followed by a very shallow decay, a normal decay followed by late steep decay. Here we aimed to verify the consistency of our sampled Swift / XRT data with theoretically proposed canonical X -ray model. For this purpose, a sample of nine afterglow data randomly identified from Swift / XRT data catalogues that detected over the past ten to fifteen years. The data analysed using jupyter lab software, and various fitting parameters are generated and interpreted to justify our objectives. The results of temporal analysis show that, the dominant fraction (67%) of sampled data consistent with the shallow phase [0.5 < 2 < -1] and normal phase [1 < 3 < 1.5]. On the other hand, the analysis of data tells us, the majority of long afterglow GRBs (80 %) characterized by larger amplitudes, that indicates long afterglows associated with higher energy than short afterglows. Results of analysis also show, 67% of the sampled has R2 value nearly closer to 1, which implies the data distributed about best fitting line. Similarly, correlation coefficients of all the sampled range between -0.98 and -1.00, which indicates there is a strong negative relationship between the variables, and agreed with power law decay. Error bars on the top of histograms tell the fluctuation of photons count about mean value. On our histograms, fluctuation of photons in short GRBs afterglow higher than that of long GRBs, that ensures both classes from different sources.
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Gamma-Ray Burst, Prompt and Afterglow Emission, Fireball Shock Internal - External Shocks, Synchrotron and Inverse Compton Scattering