Issue |
EAS Publications Series
Volume 61, 2013
Gamma-ray Bursts: 15 Years of GRB Afterglows – Progenitors, Environments and Host Galaxies from the Nearby to the Early Universe
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Page(s) | 203 - 209 | |
Section | Chapter V: Afterglow Emission-I Long GRBs (Observations) | |
DOI | https://doi.org/10.1051/eas/1361030 | |
Published online | 22 July 2013 |
A.J. Castro-Tirado, J.Gorosabel and I.H. Park (eds)
EAS Publications Series, 61 (2013) 203-209
Implications of early time observations of optical afterglows of GRBs
1 ARIES, Manora Peak, Nainital
263129, Uttarakhand,
India
2 Randall Laboratory of Physics,
University of Michigan, 450 Church
Street, Ann Arbor,
MI
48109-1040,
USA
Optical observations of afterglows at very times are very useful towards understanding the least known problem of GRB research field i.e. the transition from prompt emission to early afterglows. The comparison of a subset of well-monitored GRBs and their early time properties at optical are compared with that seen at XRT and BAT wavelengths. In most of the observed cases, the very early optical observations of GRBs do not trace the canonical decay nature seen at XRT wavelengths, suggesting different origins for the observed early emissions in the two bands. In some of the early optical light-curves, the decay followed by smooth rise features are consistent with the onset of the afterglow although such features are also expected if the emission is seen off-axis and/or the outflow is structured.
© EAS, EDP Sciences 2013