Temporal variability of GRB early X-ray afterglows and GRB080319B prompt emission
Abstract
We performed the first systematic search for the minimum variability time scale between 0.3 and 10 keV studying the 28 brightest early (<3000 s) afterglows detected by Swift-XRT up to March 2008. We adopt the power spectrum analysis in the time domain: unlike the Fourier spectrum, this is suitable to study the rms variations at different time-scales. We find that early XRT afterglows show variability in excess of the Poissonian noise level on time-scales as short as about 1 s (rest frame value), with the shortest t_{min} associated with the highest energy band. The gamma-ray prompt emission of GRB080319B shows a characteristic average variability time-scale t_{var} of about 1s; this parameter undergoes a remarkable evolution during the prompt emission (BAT observation).
Keywords
Cite
@article{arxiv.0809.0189,
title = {Temporal variability of GRB early X-ray afterglows and GRB080319B prompt emission},
author = {R. Margutti and C. Guidorzi and G. Chincarini and F. Pasotti and S. Covino and J. Mao},
journal= {arXiv preprint arXiv:0809.0189},
year = {2009}
}
Comments
To be published in the "2008 Nanjing GRB Conference" conference proceedings