Browsing by Author "Kidger, M."

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    PRIMARY BLACK HOLE SPIN IN OJ 287 AS DETERMINED BY THE GENERAL RELATIVITY CENTENARY FLARE
    (IOP Publishing Ltd, 2016-03-10) 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 Gomez, J.; Caton, D. B.; Chavushyan, V.; Dalessio, J.; Debski, B.; Dimitrov, D.; Drozdz, M.; Er, H.; Erdem, A.; Escartin Perez, A.; Ramazani, V. Fallah; Filippenko, A. V.; Ganesh, S.; Garcia, F.; Gomez 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 Gonzalez, J. -L.; Sameer; Schweyer, T.; Siwak, M.; Soldan Alfaro, F. C.; Sonbas, E.; Steele, I.; Stocke, J. T.; Strobl, J.; Takalo, L. O.; Tomov, T.; Tremosa Espasa, L.; Valdes, J. R.; Valero Perez, 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.; University of Turku; Jagiellonian University; Pedagogical University of Cracow; Agenzia Spaziale Italiana (ASI); Istituto Nazionale di Fisica Nucleare (INFN); Tata Institute of Fundamental Research (TIFR); Osaka University of Education; European Space Agency; National & Kapodistrian University of Athens; Department of Space (DoS), Government of India; Physical Research Laboratory - India; Canakkale Onsekiz Mart University; University of North Carolina; Appalachian State University; Instituto Nacional de Astrofisica, Optica y Electronica; University of Delaware; Bulgarian Academy of Sciences; Ataturk University; University of California System; University of California Berkeley; Department of Science & Technology (India); Aryabhatta Research Institute of Observational Sciences (ARIES); University of North Carolina Chapel Hill; Czech Academy of Sciences; Astronomical Institute of the Czech Academy of Sciences; Czech Technical University Prague; Tohoku University; University of Alabama Tuscaloosa; Korea Astronomy & Space Science Institute (KASI); University of Science & Technology (UST); Istituto Nazionale Astrofisica (INAF); University of Helsinki; Max Planck Society; Technical University of Munich; Adiyaman University; University of Colorado System; University of Colorado Boulder; Nicolaus Copernicus University; State University System of Florida; Florida International University; Kiepenheuer Institut fur Sonnenphysik; University of Zielona Gora; Isaac Newton Group of Telescopes
    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, 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 10% accuracy during the present decade.
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    A Search for QPOs in the Blazar OJ287: Preliminary Results from the 2015/2016 Observing Campaign
    (2016) Zola, S.; Valtonen, M.; Bhatta, G.; Goyal, A.; Debski, B.; Baran, A.; Krzesinski, J.; Siwak, M.; Ciprini, S.; Gopakumar, A.; Jermak, H.; Nilsson, K.; Reichart, D.; Matsumoto, K.; Sadakane, K.; Gazeas, K.; Kidger, M.; Piirola, V.; Alicavus, F.; Baliyan, K. S.; Berdyugin, A.; Boyd, D.; Campas Torrent, M.; Campos, F.; Carrillo Gomez, J.; Caton, D. B.; Chavushyan, V.; Dalessio, J.; Dimitrov, D.; Drozdz, M.; Er, H.; Erdem, A.; Escartin Perez, A.; Fallah Ramazani, V.; Filippenko, A. V.; Garcia, F.; Gomez Pinilla, F.; Gopinathan, M.; Haislip, J. B.; Harmanen, J.; 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.; Reinthal, R.; Sadegi, S.; Sakanoi, T.; Sameer; Salto Gonzalez, J.L.; Schweyer, T.; Soldan Alfaro, F. C.; Karaman, N.; Sonbas, E.; Steele, I.; Stocke, J. T.; Strobl, J.; Takalo, L. O.; Tomov, T.; Tremosa Espasa, L.; Valdes, J. R.; Valero Perez, J.; Verrecchia, F.; Webb, J. R.; Yoneda, M.; Zejmo, M.; Zheng, W.; Telting, J.; Saario, J.; Reynolds, T.; Kvammen, A.; Gafton, E.; Karjalainen, R.; Blay, P.; University of Alabama Tuscaloosa
    We analyse the light curve in the R band of the blazar OJ287, gathered during the 2015/2016 observing season. We did a search for quasi-periodic oscillations (QPOs) using several methods over a wide range of timescales. No statistically significant periods were found in the high-frequency domain both in the ground-based data and in Kepler observations. In the longer-period domain, the Lomb-Scargle periodogram revealed several peaks above the 99% significance level. The longest one-about 95 days-corresponds to the innermost stable circular orbit (ISCO) period of the more massive black hole. The 43-day period could be an alias, or it can be attributed to accretion in the form of a two-armed spiral wave. © 2016 by the authors.