Evidence for interaction with a surrounding medium in several BL lacertae objects.
In February 1997, we obtained multi-frequency polarization VLBA observations of 23 sources from a complete sample of northern BL Lac objects. Total intensity and linear polarization images of two sources (0745+241 and 0820+225) showing evidence for the presence of sheaths of longitudinal magnetic fi...
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| Format: | Conference item |
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2002
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| Summary: | In February 1997, we obtained multi-frequency polarization VLBA observations of 23 sources from a complete sample of northern BL Lac objects. Total intensity and linear polarization images of two sources (0745+241 and 0820+225) showing evidence for the presence of sheaths of longitudinal magnetic field surrounding their jets are presented. These results suggest that appreciable amounts of thermal plasma are often present on parsec scales, and that the jet magnetic field can be influenced by interaction with this surrounding medium. |
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