Pulsarwindnebel

Pulsarwindnebel, or pulsar wind nebula (PWN), is a nebula powered by the relativistic wind from a young, rapidly spinning neutron star called a pulsar, left behind after a core-collapse supernova. The pulsar drives a magnetized plasma outflow into the surrounding medium, and where this wind meets the ambient material a termination shock forms. At this shock, particles are accelerated to ultra-relativistic energies, and the nebula becomes a reservoir of energetic electrons and positrons that emit across a broad range of wavelengths.

The emission from PWNe is predominantly non-thermal and extends from radio to X-ray wavelengths, with gamma rays produced by inverse Compton scattering of ambient photons. The primary radiative mechanism is synchrotron radiation as high-energy particles spiral in the nebular magnetic field. Morphologically, PWNe often exhibit torus-like structures and polar jets aligned with the pulsar’s spin axis, though shapes can be affected by the surrounding supernova remnant and interstellar environment. The nebula generally expands as the remnant evolves, with its brightness tied to the pulsar’s spin-down power and the density of the ambient medium.

PWNe are important laboratories for studying particle acceleration and magnetohydrodynamics under extreme conditions. They are typically identified by their broad, non-thermal spectra and lack of strong thermal emission lines. Many PWNe reside inside supernova remnants, especially in younger systems, though interactions with the reverse shock can distort or displace them. Notable examples include the Crab Nebula, 3C 58, G21.5-0.9, and Vela X.