The Coma cluster magnetic field from Faraday rotation measures

Understand

The aim of the present work is to constrain the Coma cluster magnetic field strength, its radial profile and power spectrum by comparing Faraday Rotation Measure (RM) images with numerical simulations of the magnetic field.

• We have analyzed polarization data for seven radio sources in the Coma cluster field observed with the Very Large Array at 3.6, 6 and 20 cm, and derived Faraday Rotation Measures with kiloparsec scale resolution.
• Random three dimensional magnetic field models have been simulated for various values of the central intensity B_0 and radial power-law slope eta, where eta indicates how the field scales with respect to the gas density profile.
• We derive the central magnetic field strength, and radial profile values that best reproduce the RM observations.