Gyro-Synchrotron Radiation from Microquasars?

Gyro-synchrotron radiation occurs when the harmonic number, i.e. the ratio of observing frequency to cyclotron frequency is low, ? 100, and for low energy electrons, when the radiation is no longer predominantly beamed in the direction of the motion of radiating electrons. The circular motion of the electrons gives rise to high levels of circular polarization. In this paper we calculate the levels of circular polarization expected from a jet given the likely conditions in microquasars, and find that the properties of the circular polarization observed in GRS 1915+105 and SS433 can be easily explained.