Primary black hole spin in OJ287 as determined by the General Relativity centenary flare

• Published in: arXiv.org
• Main Authors: 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, Torrent, M Campas, Campos, F, J Carrillo Gomez, Caton, D B, Chavushyan, V, Dalessio, J, Debski, B, Dimitrov, D, Drozdz, M, H Er, Erdem, A, A Escartin Perez, V Fallah Ramazani, Filippenko, A V, Ganesh, S, Garcia, F, F Gomez Pinilla, 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, R Naves Nogues, 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 Gonzalez, J L, Schweyer, T, Siwak, M, Soldan Alfaro, F C, Sonbas, E, Steele, I, Stocke, J T, Strobl, J, Takalo, L O, Tomov, T, L Tremosa Espasa, Valdes, J R, J Valero Perez, 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
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 14.03.2016
• Subjects: Black holes; Mathematical models; Optical polarization; Outbursts; Physics - High Energy Astrophysical Phenomena; Quasars; Relativity
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1603.04171

OJ287 is a quasi-periodic quasar with roughly 12 year optical cycles. It displays prominent outbursts which are predictable in a binary black hole model. The model predicted a major optical outburst in December 2015. 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, chi = 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 a 10 % accuracy during the present decade.