Galaxies (Oct 2016)

A Search for QPOs in the Blazar OJ287: Preliminary Results from the 2015/2016 Observing Campaign

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

DOI
https://doi.org/10.3390/galaxies4040041
Journal volume & issue
Vol. 4, no. 4
p. 41

Abstract

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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.

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