Magnetic Fields in Supernova Remnants and Pulsar-Wind Nebulae

By S. Reynolds, B. Gaensler, F. Bocchino. 2011

132 citations recorded by the source corpus.

We review the observations of supernova remnants (SNRs) and pulsar-wind nebulae (PWNe) that give information on the strength and orientation of magnetic fields. Radio polarimetry gives the degree of order of magnetic fields, and the orientation of the ordered component. Many young shell supernova remnants show evidence for synchrotron X-ray emission. The spatial analysis of this emission suggests that magnetic fields are amplified by one to two orders of magnitude in strong shocks. Detection of several remnants in TeV gamma rays implies a lower limit on the magnetic-field strength (or a measurement, if the emission process is inverse-Compton upscattering of cosmic microwave background photons). Upper limits to GeV emission similarly provide lower limits on magnetic-field strengths. In the historical shell remnants, lower limits on B range from 25 to 1000 μG. Two remnants show variability of synchrotron X-ray emission with a timescale of years. If this timescale is the electron-acceleration or radiative loss timescale, magnetic fields of order 1 mG are also implied. In pulsar-wind nebulae, equipartition arguments and dynamical modeling can be used to infer magnetic-field strengths anywhere from ∼5 μG to 1 mG. Polarized fractions are considerably higher than in SNRs, ranging to 50 or 60% in some cases; magnetic-field geometries often suggest a toroidal structure around the pulsar, but this is not universal. Viewing-angle effects undoubtedly play a role. MHD models of radio emission in shell SNRs show that different orientations of upstream magnetic field, and different assumptions about electron acceleration, predict different radio morphology. In the remnant of SN 1006, such comparisons imply a magnetic-field orientation connecting the bright limbs, with a substantial density gradient across the remnant.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/6d51dcbe7d7e0d171d84c8267a8d126d4643ab27

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In Astronomy and Astrophysics

1. A. Bykov
2. J. Vink
3. J. C. Raymond
4. Y. Ohira
5. R. Terrier
6. E. Helder
7. P. Blasi
8. Michela Mapelli

In Nuclear and High Energy Physics

1. A. Bykov
2. J. Vink
3. J. C. Raymond
4. Y. Ohira
5. R. Terrier
6. E. Helder
7. P. Blasi

Citations in the corpus

• Sensitivity of the high altitude water Cherenkov detector to sources of multi-TeV gamma rays (2013, unknown): “Pulsar Wind Nebulae (PWN) are the most common Galactic source of TeV gamma rays [26,27].”
• Observational Signatures of Particle Acceleration in Supernova Remnants (2012, background): “, 2007), with the possible exception of one filament in the northeast of Tycho’s supernova remnant (Reynolds et al., 2011).”