Fluctuations in the Galactic Magnetic Field [chapter]

James M. Cordes, Andrew Clegg, John Simonetti
1990 Galactic and Intergalactic Magnetic Fields  
We discuss small scale structure in the Galactic magnetic field as inferred from Faraday rotation measurements of extragalactic radio sources. The rotation measure data suggest a continuum of length scales extending from parsec scales down to at least 0.01 pc and perhaps to as small as 10 9 cm. Such turbulence in the magnetic field comprises a reservoir of energy that is comparable to the energy in the large scale field. SM = j ds j d 3 q n\(q). "'o <l AU Combinations of RM,DM,SM may be used to
more » ... M,SM may be used to infer the nature of small scale variations in n e , B, and their product n e B. Here we emphasize the discussion of the magnetic field. The main topics discussed are: (1) Distinguishing intrinsic and Galactic RMs; (2) Distinguishing large scale systematic Β and small scale random B\ (3) The wavenumber spectra of SB and Sn e ; and (4) Energetics of SB 'turbulence.' 2. Rotation Measures Rotation measures vary between the lobes of double radio sources; most of this appears due to magnetoionic material in the Galaxy because the rms RM is strongly 55 R. Beck et al. (eds.), Galactic and Intergalactic Magnetic Fields, 55-58.
doi:10.1007/978-94-009-0569-6_16 fatcat:hzzdjzoubnacbhxrcqoie5go5m