Frequency Dependence of the Parsec-scale Polarization Structures of BL Lac Objects

A.B. Pushkarev, D.C. Gabuzda, T.V. Cawthorne
2001 Symposium - International astronomical union  
BL Lacertae objects are active galactic nuclei with weak or undetectable line emission and strong variability in total intensity and linear polarization over a wide wavelength range from optical to radio. The radio emission and much of the optical emission is believed to be synchrotron radiation. Sources in the complete sample of BL Lac objects defined by Kühr and Schmidt (1990) have: 5 GHz fluxes of at least 1 Jy, radio spectral index α ≥ −0.5 (Sv˜v+α), rest frame equivalent width of the
more » ... width of the strongest emission lines less than 5 Å, and optical counterparts on the Sky Survey plates with brightness greater than 20m.
doi:10.1017/s0074180900220755 fatcat:4cucgzjjgzgbxptuanjj525bmi