On the possible mechanism of radio emission of polars

TL;DR

This paper proposes a new mechanism for radio emission in polars, based on cyclotron radiation from thermal electrons influenced by Alfvén wave turbulence, successfully explaining observed fluxes in VLA bands.

Contribution

It introduces a novel emission model for polars involving cyclotron radiation driven by magnetic field fluctuations from Alfvén turbulence.

Findings

The model reproduces observed radio fluxes of AM Her.

Expressions for radiation spectrum and polarization are derived.

The mechanism explains radio emission with realistic plasma parameters.

Abstract

We suggest a mechanism for generation of radio emission from polars. It is based on the cyclotron radiation of thermal electrons at the background of fluctuating magnetic field. The source of fluctuations is Alfv\'{e}n wave turbulence. Expressions for the radiation spectrum and degree of polarization are obtained. By the example of the polar AM~Her, the fluxes of radio emission from the accretion stream are calculated. Within the framework of proposed emission model, with realistic plasma characteristics, it is possible to reproduce observed radiation fluxes in the VLA bands.