相关论文: Multi-D magnetohydrodynamic modelling of pulsar wi…
The extended nebulae formed as pulsar winds expand into their surroundings provide information about the composition of the winds, the injection history from the host pulsar, and the material into which the nebulae are expanding.…
A complete set of diagnostic tools aimed at producing synthetic synchrotron emissivity, polarization, and spectral index maps from relativistic MHD simulations is presented. As a first application we consider here the case of the emission…
Recent observations of the Crab Nebula (Rudy et al 2015) have maintained its reputation for high energy astrophysical enlightenment and its use as a testbed for theories of the behaviour of magnetized, relativistic plasma. In particular,…
The pulsar wind model is updated by considering the effect of particle density and pulsar death. It can describe both the short term and long term rotational evolution of pulsars consistently. It is applied to model the rotational evolution…
We present four new, high-resolution VLA radio images of the Crab nebula, taken between 2001 Feb. and Apr. The radio images show systematic variability in the Crab's radio emission throughout the region near the pulsar. The principal…
We present a detailed analysis of the morphological properties of the Crab Nebula across the electromagnetic spectrum based on new and previous high-quality data from radio to X-rays. In the radio range we obtained an image of the entire…
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…
We present here a series of numerical simulations of the development of Kelvin-Helmholtz instability in a relativistically hot plasma. The physical parameters in the unperturbed state are chosen to be representative of local conditions…
Pulsar Wind Nebulae, Blazars, Gamma Ray Bursts and Magnetars all contain regions where the electromagnetic energy density greatly exceeds the plasma energy density. These sources exhibit dramatic flaring activity where the electromagnetic…
Bow shock pulsar wind nebulae (BSPWNe) are know to show a large variety of shapes and morphologies, both when comparing different objects, and for the same object in different energy bands. It is unclear if such a variety is related to…
Dwarf Novae and low-mass X-ray binaries are eruptive binary systems comprised of a Roche-lobe overflowing solar-type star and an accreting compact object. Their recurrence time can be explained by a low-accreting phase, the quiescence,…
The formation of a large-scale current sheet is a generic feature of pulsar magnetospheres. If the magnetic axis is misaligned with the star rotation axis, the current sheet is an oscillatory structure filling an equatorial wedge determined…
Very high energy gamma-ray flares from the Crab nebular detected by AGILE and Fermi satellites challenge our understanding of the pulsar wind nebulae. The short duration of the flares, only few days, is particularly puzzling since it is…
The recent discovery of PeV electrons from the Crab nebula, produced on rapid time scales of one day or less with a sharply peaked gamma-ray spectrum without hard X-rays, challenges traditional models of diffusive shock acceleration…
Supernova Remnants and Pulsar Wind Nebulae are among the most significant sources of non-thermal X-rays in the sky, and the closest laboratories where relativistic plasma dynamics and particle acceleration can be investigated. Being strong…
Context: During solar flares a large number of charged particles are accelerated to high energies, but the exact mechanism responsible for this is, so far, still unclear. Acceleration in collapsing magnetic traps is one of the mechanisms…
Recent results from LHAASO and Tibet AS$\gamma$ suggest that the Crab Nebula's gamma-ray spectrum extends to the PeV energy range, however the production mechanisms of this highest energy emission remain unclear. It has been postulated that…
A pulsar wind nebula inside a supernova remnant provides a unique insight into the properties of the central neutron star, the relativistic wind powered by its loss of rotational energy, its progenitor supernova, and the surrounding…
Pulsar Wind Nebulae are the astrophysical sources that host the most relativistic shocks in Nature and the only Galactic sources in which we have direct evidence of PeV particles. These facts make them very interesting from the point of…
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…