2004/03/31 by E. W. Liang, En‐Wei Liang, Z. G. Dai +1 · 1 citation
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Distribution (mathematics) #Energy (signal processing) #Gamma-ray burst #Gamma-ray bursts and supernovae #Isotropy #Jet (fluid) #Nuclear physics #Optics #Physics #Pulsars and Gravitational Waves Research #Spectral line #Thermodynamics #X-ray #astro-ph
paper · pdf · doi:10.1086/422253
published as Astrophys.J. 608 (2004) L9-L12 · 4 pages plus 2 figures, emulateapj style, ApJ Letters, 608, in press
openalex publication_date 2004/05/13 · arxiv created 2004/05/14 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We study the peak energy (E_\rmp) distribution of the ν Fν spectra of gamma-ray bursts (GRBs) and X-ray flashes (XRFs) with a sample of 57 bursts observed by \em High Energy Transient Explorer 2 (\em HETE-2) French Gamma Telescope and discuss its implications for the jet structure models. Combining the observed E_\rmp distribution of \em HETE--2 GRBs/XRFs with that of BATSE GRBs, we find that the observed E_\rmp distribution of GRBs/XRFs is a bimodal one with peaks of \lesssim 30 keV and ∼ 160-250 keV. According to the recently-discovered equivalent-isotropic energy-E_\rmp relationship, such a bimodal distribution implies a two-component structure of GRB/XRF jets. A simple simulation analysis shows that this structured jet model does roughly reproduce a bimodal distribution with peaks of ∼ 15 and ∼ 200 keV. We argue that future observations of the peak of ∼ 15 keV in the E_\rmp distribution would be evidence supporting this model. \em Swift, which covers an energy band of 0.2--150 keV, is expected to provide a key test for our results.