• DOI:10.1038/207059a0
• Corpus ID: 123416790

Evidence for an Unusual Source of High Radio Brightness Temperature in the Crab Nebula

@article{Hewish1965EvidenceFA,
  title={Evidence for an Unusual Source of High Radio Brightness Temperature in the Crab Nebula},
  author={Antony Hewish and S. E. Okoye},
  journal={Nature},
  year={1965},
  volume={207},
  pages={59-60}
}

• A. Hewish, S. Okoye
• Published 1 July 1965
• Physics
• Nature

working at A = 3·39μ. While the accuracy achieved was poorer than that of the latter method, considerable refinement of the accuracy should be possible. Moreover, the difficulties which arise in the interferometric method from the need to follow increases and decreases of density to a point wherE the density is known do not occur, and a spot density measurement can be made in a fraction of a m.icrosecond without reference to tho provious or subsequent behaviour of the plasma. In the general case, however, when the magnetic fields are not known, the two methods are complementary; tho Faraday rotation gives information on the magnetic fiold while the interferometer does not. Since the effect on an infra-red beam of transverse components of the magnetic field is normally negligible compared with that of very much smaller longitudinal components, the l J<'araday rotation along a path-length l measuros f nB. ds 0 while the phase shift measured interferometrically 1s l proportional to fn ds. 0 We thank Dr. R. J. Bickerton for his advice, and Mr. B. Parham for help with the measurements. The experiments were m2.de possible by the generous loan of the laser from Services Electronics Research Laboratory, Baldock, and by the supply of infra-red detectors from the Radar Research Establishment, Malvern.