Refereed journal article or data article (A1)
Stochastic Modeling of Multiwavelength Variability of the Classical BL Lac Object OJ287 on Timescales Ranging from Decades to Hours
List of Authors: Goyal A, Stawarz L, Zola S, Marchenko V, Soida M, Nilsson K, Ciprini S, Baran A, Ostrowski M, Wiita PJ, Gopal-Krishna, Siemiginowska A, Sobolewska M, Jorstad S, Marscher A, Aller MF, Aller HD, Hovatta T, Caton DB, Reichart D, Matsumoto K, Sadakane K, Gazeas K, Kidger M, Piirola V, Jermak H, Alicavus F, Baliyan KS, Baransky A, Berdyugin A, Blay P, Boumis P, Boyd D, Bufan Y, Torrent MC, Campos F, Gomez JC, Dalessio J, Debski B, Dimitrov D, Drozdz M, Er H, Erdem A, Perez AE, Ramazani VF, Filippenko AV, Gafton E, Garcia F, Godunova V, Pinilla FG, Gopinathan M, Haislip JB, Haque S, Harmanen J, Hudec R, Hurst G, Ivarsen KM, Joshi A, Kagitani M, Karaman N, Karjalainen R, Kaur N, Koziel-Wierzbowska D, Kuligowska E, Kundera T, Kurowski S, Kvammen A, LaCluyze AP, Lee BC, Liakos A, de Haro JL, Moore JP, Mugrauer M, Nogues RN, Neely AW, Ogloza W, Okano S, Pajdosz U, Pandey JC, Perri M, Poyner G, Provencal J, Pursimo T, Raj A, Rajkumar B, Reinthal R, Reynolds T, Saario J, Sadegi S, Sakanoi T, Gonzalez JLS, Sameer, Simon AO, Siwak M, Schweyer T, Alfaro FCS, Sonbas E, Strobl J, Takalo LO, Espasa LT, Valdes JR, Vasylenko VV, Verrecchia F, Webb JR, Yoneda M, Zejmo M, Zheng W, Zielinski P, Janik J, Chavushyan V, Mohammed I, Cheung CC, Giroletti M, Giroletti M
Publisher: IOP PUBLISHING LTD
Publication year: 2018
Journal: Astrophysical Journal
Journal name in source: ASTROPHYSICAL JOURNAL
Journal acronym: ASTROPHYS J
Article number: ARTN 175
Volume number: 863
Issue number: 2
Number of pages: 20
ISSN: 0004-637X
eISSN: 1538-4357
DOI: http://dx.doi.org/10.3847/1538-4357/aad2de
Self-archived copy’s web address: https://research.utu.fi/converis/portal/detail/Publication/35664650
We present the results of our power spectral density analysis for the BL Lac object OJ 287, utilizing the Fermi-LAT survey at high-energy.-rays, Swift-XRT in X-rays, several ground-based telescopes and the Kepler satellite in the optical, and radio telescopes at GHz frequencies. The light curves are modeled in terms of continuous-time autoregressive moving average (CARMA) processes. Owing to the inclusion of the Kepler data, we were able to construct for the first time the optical variability power spectrum of a blazar without any gaps across similar to 6 dex in temporal frequencies. Our analysis reveals that the radio power spectra are of a colored-noise type on timescales ranging from tens of years down to months, with no evidence for breaks or other spectral features. The overall optical power spectrum is also consistent with a colored noise on the variability timescales ranging from 117 years down to hours, with no hints of any quasi-periodic oscillations. The X-ray power spectrum resembles the radio and optical power spectra on the analogous timescales ranging from tens of years down to months. Finally, the.-ray power spectrum is noticeably different from the radio, optical, and X-ray power spectra of the source: we have detected a characteristic relaxation timescale in the Fermi-LAT data, corresponding to similar to 150 days, such that on timescales longer than this, the power spectrum is consistent with uncorrelated (white) noise, while on shorter variability timescales there is correlated (colored) noise.
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