Related papers: Magnetic dissipation in the Crab Nebula
The Crab Pulsar Wind Nebula is the best studied source of $\gamma$-ray astrophysics. The contribution of the various soft radiation fields to the Inverse Compton component of its high energy emission, the strenght of the internal magnetic…
Synchrotron radiation of ultra-relativistic particles accelerated in a pulsar wind nebula may dominate its spectrum up to gamma-ray energies. Because of the short cooling time of the gamma-ray emitting electrons, the gamma-ray emission zone…
In this letter, we describe results of new high-resolution axisymmetric relativistic MHD simulations of Pulsar Wind Nebulae. The simulations reveal strong breakdown of the equatorial symmetry and highly variable structure of the pulsar wind…
An axisymmetric model for the Crab Nebula is constructed to examine the flow dynamics in the nebula. The model is based on that of Kennel and Coroniti (1984), although we assume that the kinetic-energy-dominant wind is confined in an…
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…
A plausible model for the Crab Nebula is one in which a particle dominated, highly relativistic wind from the pulsar passes through a shock front in which the particles attain a power law energy distribution. The electrons and positrons…
We show that the mysterious, rapidly variable emission at ~400 MeV observed from the Crab Nebula by the AGILE and Fermi experiments could be the result of a sudden drop in the mass-loading of the pulsar wind. The current required to…
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…
We can probe observationally and reproduce theoretically intricate properties of the Crab Nebula nearest to the pulsar - The Inner Knot. The tiny knot is indeed a bright spot on the surface of a quasi-stationary magnetic relativistic shock…
A model of an accelerated expansion of the Crab Nebula powered by the spinning-down Crab pulsar is proposed, in which time dependence of the acceleration is connected with evolution of pulsar luminosity. Using recent observational data, we…
The Crab Nebula was formed after the collapse of a massive star about a thousand years ago, leaving behind a pulsar that inflates a bubble of ultra-relativistic electron-positron pairs permeated with magnetic field. The observation of brief…
My thesis deals with a fundamental question of high energy gamma-ray astronomy. Namely, I studied the cut-off shape of the Crab pulsar spectrum to distinguish between the leading scenarios for the pulsar models. Pulsars are celestial…
Recent observations suggest that many old pulsar wind nebulae (PWNe) are bright TeV gamma-ray sources without a strong X-ray counterpart. In this paper, we study the spectral evolution of PWNe taking into account the energy which was…
We study the spectral evolution of PWNe taking into account the energy injected when they are young. We model the evolution of the magnetic field inside a uniformly expanding PWN. Considering time dependent injection from the pulsar and…
One of the most intriguing results from the gamma-ray instruments in orbit has been the detection of powerful flares from the Crab Nebula. These flares challenge our understanding of pulsar wind nebulae and models for particle acceleration.…
In this paper we present, for the first time, simulated maps of the circularly polarized synchrotron emission from the Crab nebula, using multidimensional state of the art models for the magnetic field geometry. Synchrotron emission is the…
Neutron stars generate powerful winds of relativistic particles that form bright synchrotron nebulae around them. Polarimetry provides a unique insight into the geometry and magnetic configuration of the wind, but high-energy measurements…
The oblique geometry of pulsar wind termination shock ensures that the Doppler beaming has a strong impact on the shock emission. We illustrate this using recent relativistic MHD simulations of the Crab Nebula and also show that the…
The Crab pulsar and its nebula are among the most studied astrophysical systems, and constitute one of the most promising environments where high energy processes and particle acceleration can be investigated. They are the only objects for…
This paper deals with the Crab Nebula problem to suggest that particle acceleration takes place not only at the inner shock but also over a larger region in the nebula with disordered magnetic field. Kennel and Cornoniti (1984) constructed…