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Rapidly Evolving Circularly Polarized Emission during the 1994 Outburst of GRO J1665-40

J-P Macquart·K. Wu·R. J. Sault·D. C. Hannikainen
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Abstract

We report the detection of circular polarization during the 1994 outburst of the Galactic microquasar GRO J1655-40. The circular polarization is clearly detected at 1.4 and 2.4GHz, but not at 4.8 and 8.4GHz, where its magnitude never exceeds 5 mJy. Both the sign and magnitude of the circular polarization evolve during the outburst. The time dependence and magnitude of the polarized emission can be qualitatively explained by a model based on synchrotron emission from the outbursts, but is most consistent with circular polarization arising from propagation effects through the relativistic plasma surrounding the object.

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J-P Macquart, K. Wu, R. J. Sault, D. C. Hannikainen. 2002-10-01. Rapidly Evolving Circularly Polarized Emission during the 1994 Outburst of GRO J1665-40. https://doi.org/10.1051/0004-6361%3A20021428

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