Related papers: Implication of Jet Physics from MeV Line Emission …
As the brightest gamma-ray burst ever observed, GRB 221009A provided a precious opportunity to explore spectral line features. In this paper, we performed a comprehensive spectroscopy analysis of GRB 221009A jointly with GECAM-C and…
The highly variable and energetic pulsed emission of a long gamma-ray burst (GRB) is thought to originate from local, rapid dissipation of kinetic or magnetic energy within an ultra-relativistic jet launched by a newborn compact object,…
Gamma-ray bursts (GRBs) have long been considered potential sources of ultra-high-energy cosmic rays (UHECRs; with energy $\gtrsim 10^{18} {\rm~eV}$). In this work, we propose a novel model generating MeV emission lines in GRB, which can…
The brightest-of-all-time gamma-ray burst (GRB), GRB 221009A, is the first GRB observed to have emission line (up to 37 MeV) in its prompt emission spectra. It is naturally explained as \pair annihilation line that was Doppler boosted in…
Gamma-ray bursts (GRBs) are believed to launch relativistic jets, which generate prompt emission by internal processes, and produce long-lasting afterglows by driving external shocks into surrounding medium. However, how the jet powers the…
Even though the prompt emission of gamma-ray bursts (GRBs) is highly beamed, high-latitude emission still produces a distinct light curve break after the intrinsic emission ceases and the edge of the jet comes into view. This curvature…
The long-term evolution of relativistic jets in gamma-ray bursts (GRBs), particularly from days to months post-burst, remains a fundamental puzzle in astrophysics. Here, we report our very long baseline interferometry observation of the…
The Lorentz factor of a relativistic jet and its evolution during the jet expansion are difficult to estimate, especially for the jets in gamma-ray bursts (GRBs). However, it is related to the understanding of jet physics. Owing to the…
Detection of spectral line in gamma-ray bursts (GRBs) is importance for studying GRB physics, as it provides insights into the composition and physical conditions of the GRB environment. However, progress in detecting X-ray or gamma-ray…
Gamma-ray bursts (GRBs) are powered by ultra-relativistic jets. The launching sites of these jets are surrounded by dense media, which the jets must cross before they can accelerate and release the high energy emission. Interaction with the…
As a characteristic feature of the spectrum, the emission line carries critical information on the underlying physics of the radiation. After extensive efforts in decades, the first high-significant detection of a series of emission lines…
The emission region of $\rm \gamma$-ray bursts (GRBs) is poorly constrained. The uncertainty on the size of the dissipation site spans over 4 orders of magnitude ($\rm 10^{12}-10^{17}$ cm) depending on the unknown energy composition of the…
Gamma-ray bursts (GRBs) are luminous stellar explosions characterized by the ejection of relativistic jets. This work proposes a novel paradigm to study these GRB jets. By analyzing the timing information of prompt pulses and X-ray flares,…
Gamma-ray bursts (GRB) are generally believed to be efficient particle accelerators. In the presence of energetic protons in a GRB jet, interactions between these protons and intense radiation field of the GRB are supposed to induce…
The second brightest GRB in history, GRB230307A, provides an ideal laboratory to study the mechanism of GRB prompt emission thanks to its extraordinarily high photon statistics and its single episode activity. Here we demonstrate that the…
Gamma-ray bursts (GRBs) are the most energetic explosions in the universe, and their afterglow emission provides an opportunity to probe the physics of relativistic shock waves in an extreme environment. Several key pieces for completing…
GRB 221009A ($z=0.151$) is one of the closest known long $\gamma$-ray bursts (GRBs). Its extreme brightness across all electromagnetic wavelengths provides an unprecedented opportunity to study a member of this still-mysterious class of…
In this study, the light curves and spectrum of the photospheric thermal radiation from ultrarelativistic gamma-ray burst (GRB) jets are calculated using 2D relativistic hydrodynamic simulations of jets from a collapsar. As the jet…
The prompt optical emission that arrives with gamma-rays from a cosmic gamma-ray burst (GRB) is a signature of the engine powering the burst, the properties of the ultra-relativistic ejecta of the explosion, and the ejecta's interactions…
Despite decades of investigations, the physical mechanism that powers the bright prompt $\gamma$-ray emission from gamma-ray bursts (GRBs) is still not identified. One important observational clue that remains not properly interpreted so…