Polarization of synchrotron emission from relativistic reconfinement shocks |
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Authors: | Krzysztof Nalewajko |
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Institution: | Nicolaus Copernicus Astronomical Center, Bartycka 18, 00-716 Warsaw, Poland |
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Abstract: | We study the polarization properties of relativistic reconfinement shocks with chaotic magnetic fields. Using our hydrodynamical model of their structure, we calculate synthetic polarization maps, longitudinal polarization profiles and discuss the spatially averaged polarization degree as a function of jet half-opening angle Θ j , jet Lorentz factor Γ j and observer inclination angle to the jet axis θobs . We find that for θobs?Θ j the wave electric vectors are parallel in the vicinity of the structure ends and perpendicular in between, while for θobs > Θ j the polarization can only be perpendicular. The spatially averaged polarization degree does not exceed 30 per cent. Parallel average polarization, with polarization degrees lower than 10 per cent, has been found for θobs < Θ j under the condition Γ j Θ j > 1 . As earlier works predicted the parallel polarization from relativistic conical shocks, we explain our results by discussing conical shocks with divergent upstream flow. |
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Keywords: | polarization shock waves galaxies: jets |
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