Intraday Variability Statistics in Radio-Selected and X-Ray Selected BL Lac Objects

Implications for Unified schemes
  • J. Heidt
Conference paper
Part of the International Astronomical Union book series (IAUS, volume 175)


BL Lac objects, characterized by their high variability across the electromagnetic spectrum, strong and variable polarization in the radio and optical domain and a (nearly) featureless continuum can in general be divided into the radio-selected (RBL) and X-ray selected BL Lac objects (XBL) according to their α ro α ox spectral indices (Stocke et al., 1985). Attempts to unify both classes within a single model have been suggested e.g. by Ghisellini et al. (1993) or Giommi et al. (1994).


Duty Cycle Spectral Index Variable Polarization Variability Statistic Extragalactic Radio Source 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© International Astronomical Union 1996

Authors and Affiliations

  • J. Heidt
    • 1
  1. 1.LandessternwarteKönigstuhlHeidelbergGermany

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