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arXiv · 0901.2219

The unusual X-ray light-curve of GRB 080307: the onset of the afterglow?

K. L. Page·R. Willingale·P. T. O'Brien·N. R. Tanvir·J. P. Osborne·B. Zhang·S. T. Holland·A. J. Levan·A. Melandri·R. L. C. Starling·D. Bersier·D. N. Burrows·J. E. Geach·P. Maxted
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Abstract

Swift-detected GRB 080307 showed an unusual smooth rise in its X-ray light-curve around 100 seconds after the burst, at the start of which the emission briefly softened. This `hump' has a longer duration than is normal for a flare at early times and does not demonstrate a typical flare profile. Using a two component power-law-to-exponential model, the rising emission can be modelled as the onset of the afterglow, something which is very rarely seen in Swift-X-ray light-curves. We cannot, however, rule out that the hump is a particularly slow early-time flare, or that it is caused by upscattered reverse shock electrons.

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K. L. Page, R. Willingale, P. T. O'Brien, N. R. Tanvir, J. P. Osborne, B. Zhang, S. T. Holland, A. J. Levan, A. Melandri, R. L. C. Starling, D. Bersier, D. N. Burrows, J. E. Geach, P. Maxted. 2009-01-15. The unusual X-ray light-curve of GRB 080307: the onset of the afterglow?. https://doi.org/10.1111/j.1365-2966.2009.14509.x

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