相关论文: Multi-collision internal shock lepto-hadronic mode…

Low-luminosity gamma-ray bursts (LL GRBs), a subclass of the most powerful transients in the Universe, remain promising sources of high-energy astrophysical neutrinos, despite strong IceCube constraints on typical long GRBs. In this work, a…

The Fermi satellite has been reporting the detailed temporal properties of gamma-ray bursts (GRBs) in an extremely broad spectral range, 8 keV - 300 GeV, in particular, the unexpected delays of the GeV emission onsets behind the MeV…

We explore several models which might be proposed to explain recent possible detections of high-energy (TeV) gamma rays in association with low-energy gamma-ray bursts (GRBs). Likely values (and/or upper limits) for the source energies in…

The ultra-relativistic jet released in gamma-ray bursts (GRBs) is expected to produce ultra-high-energy cosmic rays (UHECRs), prompt gamma-ray emission and hence prompt high-energy neutrinos by photopion interactions. In this work, we…

We explain the observed multiwavelength photon spectrum of a number of BL Lac objects detected at very high energy (VHE, $E \gtrsim 30$ GeV), using a lepto-hadronic emission model. The one-zone leptonic emission is employed to fit the…

The temporal--spectral evolution of the prompt emission of gamma-ray bursts (GRBs) is simulated numerically for both leptonic and hadronic models. For weak enough magnetic fields, leptonic models can reproduce the few seconds delay of the…

A model for high-energy (>10^14 eV) cosmic rays (HECRs) from galactic and extragalactic gamma-ray bursts (GRBs) is summarized. Relativistic outflows in GRBs are assumed to inject power-law distributions of CR protons and ions to the highest…

Gamma-ray bursts (GRBs) are promising as sources of neutrinos and cosmic rays. In the internal shock scenario, blobs of plasma emitted from a central engine collide within a relativistic jet and form shocks, leading to particle acceleration…

The principal paradigm for gamma-ray bursts (GRBs) suggests that the prompt transient gamma-ray signal arises from multiple shocks internal to the relativistic expansion. This paper explores how GRB prompt emission spectra can constrain…

The origin of ultra high energy cosmic rays (UHECR) is still unknown. However, great progress has been achieved in past years due to the good quality and large statistics in experimental data collected by the current observatories. The data…

The gamma-rays from gamma-ray bursts (GRBs) are believed to be produced by internal shocks driven by small timescale, ~1 ms, variation in the GRB outflows, and a pair-production spectral cutoff is generally expected around the GeV range.…

We discuss the production of multiple astrophysical messengers (neutrinos, cosmic rays, gamma-rays) in the Gamma-Ray Burst (GRB) internal shock scenario, focusing on the impact of the collision dynamics between two shells on the fireball…

We study the acceleration of CR protons and nuclei at GRB internal shocks. Physical quantities and their time evolution are estimated using the internal shock modeling implemented by Daigne & Mochkovitch 1998. We consider different…

We consider the acceleration of charged particles at the ultra-relativistic shocks, with Lorentz factors \Gamma_s >> 1 relative to the upstream medium, arising in relativistic fireball models of gamma-ray bursts (GRBs). We show that for…

The prompt GRB emission is thought to arise from electrons accelerated in internal shocks propagating within a highly relativistic outflow. The launch of Fermi offers the prospect of observations with unprecedented sensitivity in…

Long duration gamma-ray bursts (GRBs) are among the least understood astrophysical transients powering the high-energy universe. To date, various mechanisms have been proposed to explain the observed electromagnetic GRB emission. In this…

We present a theory of ultrarelativistic collisionless shocks based on the relativistic kinetic two-stream instability. We demonstrate that the shock front is unstable to the generation of small-scale, randomly tangled magnetic fields.…

Over the last decade, observations have shown that the mean mass of ultra-high-energy cosmic rays (UHECRs) increases progressively toward the highest energies. However, the precise composition is still unknown, and several theoretical…

The widely existing shallow decay phase of the X-ray afterglows of gamma-ray bursts (GRBs) is generally accepted to be due to long-lasting energy injection. The outflows carrying the injecting energy, based on the component that is…

We re-examine critically the arguments raised against the theory that Ultra High Energy Cosmic Rays observed at Earth are produced in Gamma Ray Bursts. These include the limitations to the highest energy attainable by protons around the…