Klein-Nishina effects on the high-energy afterglow emission of gamma-ray bursts (2009)
Wang, Xiang-Yu, He, Hao-Ning, Li, Zhuo, Wu, Xue-Feng, Dai, Zi-Gao
Extended high-energy(>100MeV) gamma-ray emission that lasts much longer than the prompt sub-MeV emission has been detected from quite a few gamma-ray bursts (GRBs) by Fermi Large Area Telescope (LAT)...
High-energy gamma-ray afterglows from low-luminosity gamma-ray bursts (2009)
He, Hao-Ning, Wang, Xiang-Yu, Yu, Yun-Wei, Meszaros, Peter
The observations of gamma-ray bursts (GRBs) such as 980425, 031203 and 060218, with luminosities much lower than those of other classic bursts, lead to the definition of a new class of GRBs --...
The early high-energy afterglow emission from Short GRBs (2009)
We calculate the high energy afterglow emission from short Gamma-Ray Bursts (SGRBs) in the external shock model. There are two possible components contributing to the high energy afterglow: the...
GRB 080916C: on the radiation origin of the prompt emission from KeV/MeV to GeV (2009)
Wang, Xiang-Yu, Li, Zhuo, Dai, Zi-Gao, Meszaros, Peter
Fermi observations of high-energy gamma-ray emission from GRB 080916C shows that its spectrum is consistent with the Band function from MeV to tens of GeV. Assuming one single emission mechanism...
Grupe, Dirk, Burrows, David N., Wang, Xiang-Yu, Zhang, Bing, Garmire, Gordon, ...
We report on 5 Chandra observations of the X-ray afterglow of the Gamma-Ray Burst GRB 060729 performed between 2007 March and 2008 May. In all five observations the afterglow is clearly detected. The...
Wang, Xiang-Yu, Li, Zhuo, Waxman, Eli, Meszaros, Peter
We suggest that non-thermal emission can be produced by multiple scatterings of the photons between the supernova ejecta and pre-shock material in supernova shock breakout. Such bulk-Comptonization...
Curvature Effect of a Non-Power-Law Spectrum and Spectral Evolution of GRB X-Ray Tails (2008)
Zhang, Bin-Bin, Zhang, Bing, Liang, En-Wei, Wang, Xiang-Yu
The apparent spectral evolution observed in the steep decay phase of many GRB early afterglows raises a great concern of the high-latitude "curvature effect" interpretation of this phase. However,...
Prompt TeV neutrinos from dissipative photospheres of gamma-ray bursts (2008)
Recently, it was suggested that a photospheric component that results from the internal dissipation occurring in the optically thick inner parts of relativistic outflows may be present in the prompt...
On the Origin and Survival of UHE Cosmic-Ray Nuclei in GRBs and Hypernovae (2007)
Wang, Xiang-Yu, Razzaque, Soebur, Meszaros, Peter
The chemical composition of the ultra-high-energy (UHE) cosmic rays serves as an important clue for their origin. Recent measurements of the elongation rates by the Pierre Auger Observatory hint at...
Photon Acceleration at Shock Breakout of Trans-Relativistic Supernova (2007)
Li, Zhuo, Wang, Xiang-Yu, Waxman, Eli, Meszaros, Peter
The predicted thermal flash from SN shock breakout might have been detected for the first time by Swift in GRB 060218/SN 2006aj. The detected thermal X-ray emission in this event implies emergence of...
High-energy Cosmic Rays and Neutrinos from Semi-relativistic Hypernovae (2007)
Wang, Xiang-Yu, Razzaque, Soebur, Meszaros, Peter, Dai, Zi-Gao
The origin of the ultrahigh-energy (UHE) cosmic rays (CRs) from the second knee ($\sim6\times10^{17}$eV) above in the CR spectrum is still unknown. Recently, there has been growing evidence that a...
High-Energy Gamma-Rays from GRB X-ray Flares (2007)
Wang, Xiang-Yu, Li, Zhuo, Meszaros, Peter
The recent detection of X-ray flares during the afterglow phase of gamma-ray bursts (GRBs) suggests an inner-engine origin, at radii inside the forward shock. There must be inverse Compton (IC)...
GRB Precursors in the Fallback Collapsar Scenario (2007)
Wang, Xiang-Yu, Meszaros, Peter
Precursor emission has been observed in a non-negligible fraction of gamma-ray bursts.The time gap between the precursor and the main burst extends in some case up to hundreds of seconds, such as in...
Grupe, Dirk, Gronwall, Caryl, Wang, Xiang-Yu, Roming, Peter, Cummings, Jay, Zhang, Bing, ...
We report the results of the Swift and XMM observations of the Swift-discovered long Gamma-Ray Burst GRB 060729 ($T_{90}$=115s). The afterglow of this burst was exceptionally bright in X-rays as well...
Nonthermal gamma-ray and X-ray flashes from shock breakout in gamma-ray bursts/supernovae (2006)
Wang, Xiang-Yu, Li, Zhuo, Waxman, Eli, Meszaros, Peter
Thermal X-ray emission which is simultaneous with the prompt gamma-rays has been detected for the first time from a supernova connected with a gamma-ray burst (GRB), namely GRB060218/SN2006aj. It has...
GeV photons from up-scattering of supernova shock breakout X-rays by an outside GRB jet (2006)
Wang, Xiang-Yu, Meszaros, Peter
Shock breakout X-ray emission has been reported for the first time from a supernova connected with a gamma-ray burst, namely GRB060218/SN2006aj. The gamma-ray emission and the power-law decaying...
GeV-TeV and X-ray flares from gamma-ray bursts (2006)
Wang, Xiang-Yu, Li, Zhuo, Meszaros, Peter
The recent detection of delayed X-ray flares during the afterglow phase of gamma-ray bursts (GRBs) suggests an inner-engine origin, at radii inside the deceleration radius characterizing the...