Variability of the BL Lacertae Objects PKS 2155-304 and OJ 287 in the Far-Ultraviolet
Maraschi, L.; Tanzi, E. G.; Tagliaferri, G.; Treves, A.
Italy
Abstract
All the ultraviolet spectra of the two bright BL Lacertae objects PKS 2155 - 304 and OJ 287 taken with the International Ultraviolet Explorer in the period 1978-1984 are examined. For each spectrum the best-fitting power law is determined and a correlation between spectral slope and intensity is searched for. The correlation, if present, is weak. This is discussed in terms of models of the continuum emission of active galactic nuclei.