Physical Parameters of the Hot Spot A of the Radio Galaxy Cygnus A

Estimates of the physical parameters of the hot spot A of the radio galaxy Cygnus A were obtained from radio astronomical observations. To estimate the physical parameters of this radio source, we took the dimensions of a spherically symmetric inhomogeneous model of the spot A (without voids inside), the spectrum of which coincides with the radio spectrum of the hot spot A. The most probable average value of the magnetic field induction (averaged over the volume of the radio source) is B = 2.7 x 10(-3) G. The average energy density of relativistic electrons is E-e = 1.8 x 10(-6) erg/cm(3). The average energy of relativistic electrons exceeds the energy of the magnetic field by eight times. The obtained parameters of hot spot A are compared with the estimates of these parameters obtained from X-ray observations. If we take the dimensions of this radio source model (theta approximate to 0.6 '') as the size of the X-ray source, then we obtain the same field B = 2.6 x 10(-3) G from X-ray observations.