The variable sources responsible for the photometric behaviour of OJ 287 in the IR-optical-UV region during 1993-1996

Hagen-Thorn, V. A.; Marchenko, S. G.; Takalo, L. O.; Sillanpää, A.; Pursimo, T.; Boltwood, P.; Kidger, M.; Gonzalez-Perez, J. N.
Bibliographical reference

Astronomy and Astrophysics Supplement, v.133, p.353-359

Advertised on:
12
1998
Number of authors
8
IAC number of authors
2
Citations
19
Refereed citations
19
Description
An analysis is performed of multicolour observations of OJ 287 carried out during the OJ-94 Project. It is found that in the optical region the variable sources have the same power-law spectrum (F_nu ~ nu (-1.5) ) irrespective of flux level. In the IR the spectrum flattens during the flare possibly because of synchrotron self-absorption. The comparison of the outburst of 1994 with those of 1971 and 1983 shows that there is a clear correlation between the power of outburst and colour indices of the variable component in each event: the larger is the outburst, the bluer is the variable source, i.e. in more powerful outbursts the energy spectrum of relativistic electrons is flatter.