Primary Black Hole Spin in OJ 287 as Determined by the General Relativity Centenary Flare

Valtonen, M. J.; Zola, S.; Ciprini, S.; Gopakumar, A.; Matsumoto, K.; Sadakane, K.; Kidger, M.; Gazeas, K.; Nilsson, K.; Berdyugin, A.; Piirola, V.; Jermak, H.; Baliyan, K. S.; Alicavus, F.; Boyd, D.; Campas Torrent, M.; Campos, F.; Carrillo Gómez, J.; Caton, D. B.; Chavushyan, V.; Dalessio, J.; Debski, B.; Dimitrov, D.; Drozdz, M.; Er, H.; Erdem, A.; Escartin Pérez, A.; Fallah Ramazani, V.; Filippenko, A. V.; Ganesh, S.; Garcia, F.; Gómez Pinilla, F.; Gopinathan, M.; Haislip, J. B.; Hudec, R.; Hurst, G.; Ivarsen, K. M.; Jelinek, M.; Joshi, A.; Kagitani, M.; Kaur, N.; Keel, W. C.; LaCluyze, A. P.; Lee, B. C.; Lindfors, E.; Lozano de Haro, J.; Moore, J. P.; Mugrauer, M.; Naves Nogues, R.; Neely, A. W.; Nelson, R. H.; Ogloza, W.; Okano, S.; Pandey, J. C.; Perri, M.; Pihajoki, P.; Poyner, G.; Provencal, J.; Pursimo, T.; Raj, A.; Reichart, D. E.; Reinthal, R.; Sadegi, S.; Sakanoi, T.; Salto González, J.-L.; Sameer; Schweyer, T.; Siwak, M.; Soldán Alfaro, F. C.; Sonbas, E.; Steele, I.; Stocke, J. T.; Strobl, J.; Takalo, L. O.; Tomov, T.; Tremosa Espasa, L.; Valdes, J. R.; Valero Pérez, J.; Verrecchia, F.; Webb, J. R.; Yoneda, M.; Zejmo, M.; Zheng, W.; Telting, J.; Saario, J.; Reynolds, T.; Kvammen, A.; Gafton, E.; Karjalainen, R.; Harmanen, J.; Blay, P.
Bibliographical reference

The Astrophysical Journal Letters, Volume 819, Issue 2, article id. L37, 6 pp. (2016).

Advertised on:
3
2016
Number of authors
91
IAC number of authors
1
Citations
118
Refereed citations
98
Description
OJ 287 is a quasi-periodic quasar with roughly 12 year optical cycles. It displays prominent outbursts that are predictable in a binary black hole model. The model predicted a major optical outburst in 2015 December. We found that the outburst did occur within the expected time range, peaking on 2015 December 5 at magnitude 12.9 in the optical R-band. Based on Swift/XRT satellite measurements and optical polarization data, we find that it included a major thermal component. Its timing provides an accurate estimate for the spin of the primary black hole, χ =0.313+/- 0.01. The present outburst also confirms the established general relativistic properties of the system such as the loss of orbital energy to gravitational radiation at the 2% accuracy level, and it opens up the possibility of testing the black hole no-hair theorem with 10% accuracy during the present decade.