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Magnetic Field Geometry in "Red" and "Blue" BL Lacs

P. Kharb·D. C. Gabuzda·P. Shastri
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Abstract

We compare the systematics of the magnetic field geometry in the "red" low-energy peaked BL Lacs (LBLs) and "blue" high-energy peaked BL Lacs (HBLs) using VLBI polarimetric images. The LBLs are primarily "radio--selected" BL Lacs and the HBLs are primarily "X-ray selected". In contrast to the LBLs, which show predominantly transverse jet magnetic fields, the HBLs show predominantly longitudinal fields. Thus, while the SED peaks of core-dominated quasars, LBLs and HBLs form a sequence of increasing frequency, the magnetic field geometry does not follow an analogous sequence. We briefly investigate possible connections between the observed parsec-scale magnetic field structures and circular polarization measurements in the literature on various spatial scales.

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P. Kharb, D. C. Gabuzda, P. Shastri. 2003-01-06. Magnetic Field Geometry in "Red" and "Blue" BL Lacs. https://doi.org/10.1023/b%3Aastr.0000004993.84117.d4

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