The complex light-curve of the afterglow of GRB071010A
Abstract
We present and discuss the results of an extensive observational campaign devoted to GRB071010A, a long-duration gamma-ray burst detected by the Swift satellite. This event was followed for almost a month in the optical/near-infrared (NIR) with various telescopes starting from about 2min after the high-energy event. Swift-XRT observations started only later at about 0.4d. The light-curve evolution allows us to single out an initial rising phase with a maximum at about 7min, possibly the afterglow onset in the context of the standard fireball model, which is then followed by a smooth decay interrupted by a sharp rebrightening at about 0.6d. The rebrightening was visible in both the optical/NIR and X-rays and can be interpreted as an episode of discrete energy injection, although various alternatives are possible. A steepening of the afterglow light curve is recorded at about 1d. The entire evolution of the optical/NIR afterglow is consistent with being achromatic. This could be one of the few identified GRB afterglows with an achromatic break in the X-ray through the optical/NIR bands. Polarimetry was also obtained at about 1d, just after the rebrightening and almost coincident with the steepening. This provided a fairly tight upper limit of 0.9% for the polarized-flux fraction.
Keywords
Cite
@article{arxiv.0804.4367,
title = {The complex light-curve of the afterglow of GRB071010A},
author = {S. Covino and P. D'Avanzo and A. Klotz and D. A. Perley and L. Amati and S. Campana and G. Chincarini and A. Cucchiara and V. D'Elia and D. Guetta and C. Guidorzi and D. A. Kann and A. Küpcü Yoldaş and K. Misra and G. Olofsson and G. Tagliaferri and L. A. Antonelli and E. Berger and J. S. Bloom and M. Böer and C. Clemens and F. D'Alessio and M. Della Valle and S. di Serego Alighieri and A. V. Filippenko and R. J. Foley and D. B. Fox and D. Fugazza and J. Fynbo and B. Gendre and P. Goldoni and J. Greiner and D. Kocevksi and E. Maiorano and N. Masetti and E. Meurs and M. Modjaz and E. Molinari and A. Moretti and E. Palazzi and S. B. Pandey and S. Piranomonte and D. Poznanski and N. Primak and P. Romano and E. Rossi and R. Roy and J. M. Silverman and L. Stella and G. Stratta and V. Testa and S. D. Vergani and F. Vitali and F. Zerbi},
journal= {arXiv preprint arXiv:0804.4367},
year = {2008}
}
Comments
11 pages, 3 figures, MNRAS, in press