@article{EatoughFalckeKaruppusamyetal.2013,
  author    = {R. P. Eatough and H. Falcke and R. Karuppusamy and K. J. Lee and D. J. Champion and E. F. Keane and G. Desvignes and D. H. F. M. Schnitzeler and L. G. Spitler and M. Kramer and B. Klein and C. Bassa and G. C. Bower and A. Brunthaler and I. Cognard and A. T. Deller and P. B. Demorest and P. C. C. Freire and A. Kraus and A. G. Lyne and A. Noutsos and B. Stappers and N. Wex},
  title     = {A strong magnetic field around the supermassive black hole at the centre of the Galaxy},
  series   = {Nature},
  volume    = {501},
  number    = {7467},
  issn      = {1476-4687},
  doi       = {10.1038/nature12499},
  pages     = {391 -- 394},
  year      = {2013},
  abstract  = {Earth’s nearest candidate supermassive black hole lies at the centre of the Milky Way1. Its electromagnetic emission is thought to be powered by radiatively inefficient accretion of gas from its environment2, which is a standard mode of energy supply for most galactic nuclei. X-ray measurements have already resolved a tenuous hot gas component from which the black hole can be fed3. The magnetization of the gas, however, which is a crucial parameter determining the structure of the accretion flow, remains unknown. Strong magnetic fields can influence the dynamics of accretion, remove angular momentum from the infalling gas4, expel matter through relativistic jets5 and lead to synchrotron emission such as that previously observed6, 7, 8. Here we report multi-frequency radio measurements of a newly discovered pulsar close to the Galactic Centre9, 10, 11, 12 and show that the pulsar’s unusually large Faraday rotation (the rotation of the plane of polarization of the emission in the presence of an external magnetic field) indicates that there is a dynamically important magnetic field near the black hole. If this field is accreted down to the event horizon it provides enough magnetic flux to explain the observed emission—from radio to X-ray wavelengths—from the black hole.},
  language  = {en}
}