Related papers: Resolving the Crab pulsar wind nebula at teraelect…
The observation of peta-electronvolt (PeV) $\gamma$-ray photons from the Crab Nebula by LHAASO has revitalised the possibility of a secondary population of hadrons producing the highest energy emission through neutral pion decay. Despite…
The unusually short durations, high luminosities, and high photon energies of the Crab Nebula gamma-ray flares require relativistic bulk motion of the emitting plasma. We explain the Crab flares as the result of randomly oriented…
Pulsar wind nebulae (PWNe) are clouds of the magnetized relativistic electron/positron plasma supplied from the central pulsar. However, the number of radio-emitting particles inside a PWN is larger than the expectation from the study of…
We develop a model of gamma-ray flares of the Crab Nebula resulting from the magnetic reconnection events in highly-magnetized relativistic plasma. We first discuss physical parameters of the Crab nebula and review the theory of pulsar…
The model for pulsar wind nebulae (PWNe) as the result of the magnetohydrodynamic (MHD) downstream flow from a shocked, relativistic pulsar wind has been successful in reproducing many features of the nebulae observed close to the central…
Young pulsars produce relativistic winds which interact with matter ejected during the supernova explosion and the surrounding interstellar gas. Particles are accelerated to very high energies somewhere in the pulsar winds or at the shocks…
The accelerative expansion of the Crab nebula's outer envelope is a mystery in dynamics as a conventional expanding blast wave decelerates when bumping into the surrounding interstellar medium. Here we show that the strong relativistic…
The Crab pulsar belongs to one of the most studied stellar objects in the sky. Since its accidental detection in 1968, its pulsed emission has been observed throughout most of the electromagnetic spectrum. Although currently one of more…
We present extensive proper motion measurements of the Crab Nebula made from Canada-France-Hawaii Telescope MegaPrime/MegaCam images taken in 2007, 2016, and 2019. A total of 19974 proper motion vectors with uncertainty…
The Crab Nebula is the brightest source in the very-high-energy (VHE) gamma-ray sky and one of the best studied non-thermal objects. The dominant VHE emission mechanism is believed to be inverse Compton scattering of low energy photons on…
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…
We report on the extremely intense and fast gamma-ray are above 100 MeV detected by AGILE from the Crab Nebula in mid-April 2011. This event is the fourth of a sequence of reported major gamma-ray flares produced by the Crab Nebula in the…
We report about very high energy (VHE) gamma-ray observations of the Crab Nebula with the MAGIC telescope. The gamma-ray flux from the nebula was measured between 60 GeV and 9 TeV. The energy spectrum can be described with a curved power…
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…
Of the known pulsar wind nebulae, 8 are good candidates for being in the early stage of evolution where the wind nebula is interacting with the freely expanding supernova ejecta. Several of these have been identified with historical…
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…
We report on a study of the gamma-ray continuum emission from the Crab supernova nebula and on a search for nuclear de-excitation gamma-ray lines. Crab is the brightest continuum source in the 1-10 MeV gamma-ray sky, and its continuum…
We construct a turbulent model of the Crab Nebula's non-thermal emission. The present model resolves a number of long-standing problems of the Kennel-Coroniti (1984) model: (i) the sigma problem; (ii) the hard spectrum of radio electrons;…
The Crab Nebula is well-described at optical wavelengths and above by a steady-state magnetohydrodynamic model due to Kennel and Coroniti (1984). Can this class of model describe other pulsar-wind nebulae? I exhibit simple generalizations…
The discovery of rapid synchrotron gamma-ray flares above 100 MeV from the Crab Nebula has attracted new interest in alternative particle acceleration mechanisms in pulsar wind nebulae. Diffuse shock-acceleration fails to explain the flares…