Title:	Diagnosing the site of gamma-ray burst prompt emission with spectral cut-off energy
Authors:	Gupta, Nayantara Zhang, Bing
Keywords:	gamma-rays: bursts gamma-rays: observations gamma-rays: theory
Issue Date:	Feb-2008
Publisher:	Royal Astronomical Society
Citation:	Monthly Notices of the Royal Astronomical Society, 2008, Vol.384, pL11
Abstract:	The site and mechanism of gamma-ray burst (GRB) prompt emission is still unknown. Although internal shocks have been widely discussed as the emission site of GRBs, evidence supporting other emission sites, including the closer-in photosphere where the fireball becomes transparent and further-out radii near the fireball deceleration radius where magnetic dissipation may be important, have been also suggested recently. With the successful operation of the GLAST experiment, prompt high-energy emission spectra from many GRBs would be detected in the near future. We suggest that the cut-off energy of the prompt emission spectrum from a GRB depends on both the fireball bulk Lorentz factor and the unknown emission radius from the central engine. If the bulk Lorentz factor could be independently measured (e.g. from early afterglow observations), the observed spectral cut-off energy can be used to diagnose the emission site of gamma-rays. This would provide valuable information to understand the physical origin of GRB prompt emission.
Description:	Restricted Access. An open-access version is available at arXiv.org (one of the alternative locations)
URI:	http://hdl.handle.net/2289/4474
ISSN:	0035-8711 1365-2966 (Online)
Alternative Location:	http://adsabs.harvard.edu/abs/2008MNRAS.384L..11G http://arxiv.org/abs/0708.2763 http://dx.doi.org/10.1111/j.1745-3933.2007.00411.x
Copyright:	2008 Royal Astronomical Society
Appears in Collections:	Research Papers (A&A)

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