Related papers: Explosive X-point collapse in relativistic magneti…
Cosmic sources of gamma-ray radiation in the GeV range are often characterized by violent variability, in particular this concerns blazars, gamma-ray bursts, and the pulsar wind nebula Crab. Such gamma-ray emission requires a very efficient…
In magnetized astrophysical outflows, the dissipation of field energy into particle energy via magnetic reconnection is often invoked to explain the observed non-thermal signatures. By means of two- and three-dimensional particle-in-cell…
Magnetic reconnection is thought to be the driver for many explosive phenomena in the universe. The energy release and particle acceleration during reconnection have been proposed as a mechanism for producing high-energy emissions and…
In 2007 September, the Crab Nebula exhibited a bright gamma-ray flare in the GeV energy range that was detected by AGILE. The observed emission at >160 MeV indicates that the radiating electrons had energies above the classical synchrotron…
The Crab Nebula is one of the most efficient accelerators in the Galaxy and the only galactic source showing direct evidence of PeV particles. In spite of this, the physical process behind such effective acceleration is still a deep…
X-ray activity of Anomalous X-ray Pulsars and Soft Gamma-Ray Repeaters may result from the heating of their magnetic corona by direct currents dissipated by magnetic reconnection. We investigate the possibility that X-ray flares and bursts…
The remarkable Crab Nebula is powered by an energetic pulsar whose relativistic wind interacts with the inner parts of the Supernova Remnant SN1054. Despite low-intensity optical and X-ray variations in the inner Nebula, the Crab has been…
We consider parametric generation of electrostatic waves in the magnetosphere of the pulsar PSR0531. It is shown that in the framework of this mechanism it is possible to convert the pulsar rotational energy into the energy of Langmuir…
A mechanism for explosive magnetic reconnection is investigated by analyzing the nonlinear evolution of a collisionless tearing mode in a two-fluid model that includes the effects of electron inertia and temperature. These effects…
Astrophysical plasmas can have parameters vastly different from the more studied laboratory and space plasmas. In particular, the magnetic fields can be the dominant component of the plasma, with energy-density exceeding the particle…
Relativistic reconnection has been invoked as a mechanism for particle acceleration in numerous astrophysical systems. According to idealised analytical models reconnection produces a bulk relativistic outflow emerging from the reconnection…
Two cases of weakly and strongly stressed X-point collapse were considered. Here descriptors weakly and strongly refer to 20 % and 124 % unidirectional spatial compression of the X-point, respectively. In the weakly stressed case, the…
The $\gamma$-ray flares from the Crab nebula observed by {\it AGILE} and {\it Fermi}-LAT between 2007-2013 reached GeV photon energies and lasted several days. The strongest emission, observed during the 2011 April "super-flare," exceeded…
We model the inner knot of the Crab Nebula as a synchrotron emission coming from the non-spherical MHD termination shock of relativistic pulsar wind. The post-shock flow is mildly relativistic; as a result the Doppler-beaming has a strong…
We study particle acceleration at the termination shock of a striped pulsar wind by integrating trajectories in a prescribed model of the magnetic field and flow pattern. Drift motion on the shock surface maintains either electrons or…
We interpret $\gamma$-ray flares from the Crab Nebula as the signature of turbulence in the pulsar's electromagnetic outflow. Turbulence is triggered upstream by dynamical instability of the wind's oscillating magnetic field, and…
Magnetic reconnection is a process whereby magnetic field lines in different directions "reconnect" with each other, resulting in the rearrangement of magnetic field topology together with the conversion of magnetic field energy into the…
Fast reconnection in magnetically dominated plasmas is widely invoked in models of dissipation in pulsar winds, gamma-ray flares in the Crab nebula, and to explain the radio nanoshots of pulsars. When current sheets evolve reaching a…
Magnetic reconnection is a fundamental plasma process associated with conversion of the embedded magnetic field energy into kinetic and thermal plasma energy, via bulk acceleration and Ohmic dissipation. In many high-energy astrophysical…
The population of gamma-ray pulsars, including Crab observed in the TeV range, and Vela detected above 50 GeV, challenges existing models of pulsed high-energy emission. Such models should be universally applicable, yet they should account…