Change search
ReferencesLink to record
Permanent link

Direct link
Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC). Stockholm University, Faculty of Science, Department of Physics.
Show others and affiliations
Number of Authors: 13
2015 (English)In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 805, no 1, 13Article in journal (Refereed) Published
Abstract [en]

We study an extensive sample of 87 gamma-ray bursts (GRBs) for which there are well-sampled and simultaneous optical and X-ray light curves. We extract the cleanest possible signal of the afterglow component. and compare the temporal behaviors of the X-ray light. curve, observed by Swift XRT, and optical data, observed by UVOT and ground-based telescopes for each individual burst. Overall we find that 62% of the GRBs. are consistent with the standard afterglow model. When more advanced modeling is invoked, up to 91% of the bursts in our sample may be consistent with the external-shock model. A large fraction of these bursts are consistent with occurring in a constant interstellar density medium (61%) while only 39% of them occur in a wind-like medium. Only nine cases have afterglow light curves that exactly match the standard fireball model prediction, having a single power-law decay in both energy bands that are observed during their entire duration. In particular, for the bursts with chromatic behavior, additional model assumptions must be made over limited segments of the light curves in order for these bursts to fully agree with the external-shock model. Interestingly, for 54% of the X-ray and 40% of the optical band observations, the end of the shallow decay (t(similar to-0.5)) period coincides with the jet-break (t(similar to-p)) time, causing an abrupt change in decay slope. The fraction of the burst that is consistent with the external-shock model is independent of the observational epochs in the rest frame of GRBs. Moreover, no cases can be explained by the cooling frequency crossing the X-ray or optical band.

Place, publisher, year, edition, pages
2015. Vol. 805, no 1, 13
Keyword [en]
methods: statistical, reference systems, X-rays: ISM
National Category
Physical Sciences
URN: urn:nbn:se:su:diva-118539DOI: 10.1088/0004-637X/805/1/13ISI: 000354991300013OAI: diva2:826513
Available from: 2015-06-25 Created: 2015-06-22 Last updated: 2015-08-13Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Li, Liang
By organisation
The Oskar Klein Centre for Cosmo Particle Physics (OKC)Department of Physics
In the same journal
Astrophysical Journal
Physical Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 28 hits
ReferencesLink to record
Permanent link

Direct link