Melandri, A;
Covino, S;
Zaninoni, E;
Campana, S;
Bolmer, J;
Cobb, BE;
Gorosabel, J;
... Vergani, SD; + view all
(2017)
Colour variations in the GRB 120327A afterglow.
Astronomy and Astrophysics
, 607
, Article A29. 10.1051/0004-6361/201731759.
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Abstract
AIMS: We present a comprehensive temporal and spectral analysis of the long Swift GRB 120327A afterglow data to investigate possible causes of the observed early-time colour variations. METHODS: We collected data from various instruments and telescopes in X-ray, ultraviolet, optical, and near-infrared bands, and determined the shapes of the afterglow early-time light curves. We studied the overall temporal behaviour and the spectral energy distributions from early to late times. RESULTS: The ultraviolet, optical, and near-infrared light curves can be modelled with a single power-law component between 200 and 2 × 104 s after the burst event. The X-ray light curve shows a canonical steep-shallow-steep behaviour that is typical of long gamma-ray bursts. At early times a colour variation is observed in the ultraviolet/optical bands, while at very late times a hint of a re-brightening is visible. The observed early-time colour change can be explained as a variation in the intrinsic optical spectral index, rather than an evolution of the optical extinction.
| Type: | Article |
|---|---|
| Title: | Colour variations in the GRB 120327A afterglow |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1051/0004-6361/201731759 |
| Publisher version: | https://doi.org/10.1051/0004-6361/201731759 |
| Language: | English |
| Additional information: | This is the published version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | gamma-ray burst: individual: GRB 120327A; dust, extinction |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10025020 |
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