TURBULENCE AND MAGNETIC-FIELDS IN ELLIPTIC GALAXIES

We discuss the physical nature of turbulence and interstellar magnetic fields in the X-ray haloes of elliptical galaxies. The turbulent velo city field is represented by two components, acoustic turbulence drive n by type I supernovae and vortical turbulence whose energy source is the stellar motion with respect to the interstellar gas. The typical v elocity of the sound-wave turbulence is 60 km s(-1) and the scale is 3 50 pc. For the vortical turbulence, these are 3 kms(-1) and 3pc, respe ctively; the latter velocity field is expected to be rather inhomogene ous. The turbulent motions drive a dynamo generating, within a galacto centric distance of 10 kpc, random magnetic fields whose strength is a bout 14 mu G at the centre and decreases to 1 mu G at radius 10 kpc; t he correlation scale is the same as that of the acoustic turbulence, i .e. a few hundred parsecs. The magnetic fields produce spatial fluctua tions in the Faraday rotation measure whose amplitude is 30 and 300 ra d m(-2), for observations with linear resolution 1 kpc and 0.1 kpc, re spectively.