Related papers: The emission mechanism in magnetically dominated G…
We show that the absence of the bright optical flashes in most {\it Swift} Gamma-ray Burst (GRB) afterglows can be explained, if the reverse shock region is magnetized with a $\sigma \sim 1$, or the emission spectrum of the electrons…
We summarize latest PIC simulation results on the radiation from Poynting jets and strongly magnetized collisionless shocks when a Poynting jet runs into cold ambient medium. We find that in all cases the radiative power output is much…
Within the internal shock scenario we consider different mechanisms of high energy ($>1$ MeV) photon production inside a Gamma Ray Burst (GRB) fireball and derive the expected high energy photon spectra from individual GRBs during the…
We review the recent observational results of the gamma-ray linear polarization of Gamma-Ray Bursts (GRBs), and discuss some theoretical implications for the prompt emission mechanism and the magnetic composition of GRB jets. We also report…
Gamma-ray bursts (GRBs) are among the most luminous sources in the universe. The nature of their emission at TeV energies is one of the most relevant open issues related to these events. The temporal and spectral features inferred from the…
We calculate the creation of electron--positron pairs in Gamma-Ray Bursts (GRBs) resulting from the collision between scattered and outward moving gamma-ray photons. The number of pairs exceeds the number of ambient medium electrons…
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…
Plasma outflows from gamma-ray bursts (GRB), pulsar winds, relativistic jets, and ultra-intense laser targets radiate high energy photons. However, radiation damping is ignored in conventional PIC simulations. In this letter, we study the…
We discuss the properties of magnetically dominated jet-like outflows from stellar mass black holes surrounded by debris tori resulting from neutron star disruption. These jets may have narrow cores (along the rotation axis) which are…
One of the most elusive features of Gamma Ray Bursts (GRBs) is the sporadic emission prior to the main prompt event observed in at least $\sim 15\%$ of cases. These precursors have spectral and temporal properties similar to the main prompt…
Binary neutron-star mergers have long been associated with short-duration gamma-ray bursts (GRBs). This connection was confirmed with the first coincident detection of gravitational waves together with electromagnetic radiation from…
The primary dissipation mechanism in jets of gamma-ray bursts (GRBs), and the high efficiency of the prompt emission are long standing issues. One possibility is strong collimation of a weakly magnetized relativistic jet by the surrounding…
We present numerical simulations of axisymmetric, magnetically driven relativistic jets. To eliminate the dissipative effects induced by a free boundary with an ambient medium we assume that the flow is confined by a rigid wall of a…
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 have been also suggested recently,…
Aims. The aim of the study is to constrain the physics of gamma-ray bursts (GRBs) by analysing the multi-wavelength afterglow data set of GRB 121024A that covers the full range from radio to X-rays. Methods. Using multi-epoch broad-band…
Gamma-ray bursts (GRBs) and following afterglows are considered to be produced by dissipation of kinetic energy of a relativistic fireball and radiation process is widely believed as synchrotron radiation or inverse Compton scattering of…
The long-lasting tension between the observed spectra of gamma ray bursts (GRBs) and the predicted synchrotron emission spectrum might be solved if electrons do not completely cool. Evidence for incomplete cooling was recently found in…
We study the synchrotron and synchrotron self-Compton (SSC) emission from internal shocks that are responsible for the prompt gamma-ray emission in GRBs, and consider the relation between these two components, taking into account the high…
Two types of relativistic jets are suggested to form near accreting black holes: a potentially ultrarelativistic Poynting-dominated jet and a Poynting-baryon jet. One source of jet matter is electron-positron pair production, which is…
The association of FRB 200428 with an X-ray burst (XRB) from the Galactic magnetar SGR 1935+2154 offers important implications for the physical processes responsible for the fast radio burst (FRB) phenomena. By assuming that the XRB…