 |
Time-domain analysis of blazar OJ 287 and the binary supermassive black hole conjecture
1 : Space Science Data Center, Italian Space Agency (ASI), Rome I-00133, Italy
2 : INFN Section of Perugia, Perugia I-06123, Italy
3 : Tuorla Observatory, Department of Physics and Astronomy, Univ. of Turku, Turku FIN-21500, Finland
4 : Finnish Centre for Astronomy with ESO, University of Turku, Turku FIN-21500, Finland
5 : Astronomical Observatory, Jagiellonian University, Krakow PL-30-244, Poland
6 : Mt. Suhora Observatory, Pedagogical University, Krakow PL-30-084, Poland
7 : INAF Observatory of Rome, Monte Porzio Catone I-00078, Italy
8 : INAF, Osservatorio Astrofisico di Torino, I-10025 Pino Torinese, Italy
The proper understanding of blazar time-domain variability at the various electromagnetic spectral bands is one goal of multifrequency astrophysics. In this frame a peculiar and controversial phenomenology is the periodicity, postulated for long-term radio or optical flux light curves of about a dozen of blazars. The well-known BL Lac object OJ 287 (PKS 0851+202, S3 0851+20, PG 0851+202, z=0.306) is not only a high-variable, peculiar, extragalactic source with hints for approximatively cyclical optical outbursts, but it also represents a case of substantial intensive and extensive (long-term) multi-frequency archive of observations. This rich, gold-mine, database allowed us a deeper analysis based on a wide range of variability timescales.
