Spectral Variability of BL Lac Objects
R. D'Amicis,
R. Nesci, E. Massaro, M. Maesano, F. Montagni and
F. D'Alessio
Publications of the Astronomical Society of Australia
19(1) 111 - 113
Published: 30 April 2002
Abstract
We present the relation between optical luminosity and spectral slope for eight BL Lac objects (3C66A, PKS 0422+00, S5 0716+71, OJ 287, ON 231, OQ 530, S5 1803+78 and BL Lacertae), derived from B, V, R, and I observations spanning a time interval of about 5 years. Four objects show a marked correlation between spectral slope and luminosity, being bluer when brighter, while for the other four the correlation is weaker or absent. Possible explanations are briefly discussed in the framework of current models of the BL Lac phenomenon.Keywords: BL Lacertae objects: individual (3C 66A, PKS 0422+004, S5 0716+71, OJ 287, ON 231, OQ 530, S5 1803+78, BL Lac)
https://doi.org/10.1071/AS01113
© ASA 2002
