Award Date

5-2011

Degree Type

Dissertation

Degree Name

Doctor of Philosophy in Astronomy

Department

Physics and Astronomy

First Committee Member

Bing Zhang, Chair

Second Committee Member

Kentaro Nagamine

Third Committee Member

Daniel Proga

Fourth Committee Member

David Burrows

Fifth Committee Member

Paul O’Brien

Graduate Faculty Representative

Pengtao Sun

Number of Pages

254

Abstract

During the prompt emission and afterglow phases, GRBs(Gamma-Ray Bursts) release their huge amount of energy not limited in gamma-ray, but in a wide range of muti-wavelengths, from radio band to GeV gamma-rays. Thanks to the recent missions of Swift and Fermi, I was able to use their multi-wavelength observation data of GRBs and study their physical natures. I have processed all the Swift BAT/XRT and Fermi GBM/LAT GRB observation data. Based on the Swift data, I have studied the following comprehensive topics: (1) high-latitude "curvature effect" of early X-ray tails of GRBs Swift XRT afterglow (2) diverse physical origins of shallow decay phase of Swift XRT afterglow. (3) Jet break (in-)consistency in both X-Ray and Optical observations. Based on the Fermi observation data, I focused on the 17 GRBs with Fermi/LAT high-energy emission and found there are three elemental spectral components, namely, a classical "Band'' function component, a quasi-thermal component and an extra non-thermal power law component extending to high energies. The detailed behaviors of these three components are extensively studied and their physical origins and corresponding jet properties and emission mechanisms are also discussed.

Keywords

Fermi; Gamma-ray bursts; Gamma ray spectrometry; Swift; X-rays

Disciplines

Astrophysics and Astronomy

Language

English


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