Polarization of radiation scattered in magnetized turbulent envelopes

¹ Instituto Nacional de Astrofísica, Óptica y Electrónica, Apartado Postal 51 y 216, CP 72000, Pue. México e-mail: silant@inaoep.mx
² Main Astronomical Observatory of the Russian Academy of Sciences, Pulkovo, St.Petersburg 196140, Russia

Received: 29 April 2005
Accepted: 25 November 2005

Abstract

We consider the single scattering of the non-polarized radiation of a central star on the electrons of a plasma circumstellar envelope. We assume that such an envelope is magnetized and consists of a turbulent plasma. Two types of envelopes are considered: a spherical envelope with the dipole magnetic field and a cone-like jet with the radial magnetic field. It is shown that the existence of turbulent motions in the envelopes drastically changes the polarization degree spectrum  and the positional angle spectrum of scattered radiation compared to the non-turbulent case. The difference in spectra can be used to estimate the ratio for the energy of magnetic fluctuations to the energy of a regular magnetic field.