Stochastic modeling of multiwavelength variability of the classical BL Lac Object OJ287 on timescales ranging from decades to hours
Files
Accepted manuscript
Date
2018-08-20
Authors
Goyal, A.
Stawarz, L.
Zola, S.
Marchenko, V.
Soida, M.
Nilsson, K.
Ciprini, Stefano
Baran, Andrzej S.
Ostrowski, M.
Wiita, P.J.
Version
Accepted manuscript
OA Version
Citation
A Goyal, L Stawarz, S Zola, V Marchenko, M Soida, K Nilsson, S Ciprini, A Baran, M Ostrowski, PJ Wiita, Gopal-Krishna, A Siemiginowska, M Sobolewska, S Jorstad, A Marscher, MF Aller, HD Aller, T Hovatta, DB Caton, D Reichart, K Matsumoto, K Sadakane, K Gazeas, M Kidger, V Piirola, H Jermak, F Alicavus, KS Baliyan, A Baransky, A Berdyugin, P Blay, P Boumis, D Boyd, Y Bufan, M Campas Torrent, F Campos, J Carrillo Gomez, J Dalessio, B Debski, D Dimitrov, M Drozdz, H Er, A Erdem, A Escartin Perez, V Fallah Ramazani, AV Filippenko, E Gafton, F Garcia, V Godunova, F Gomez Pinilla, M Gopinathan, JB Haislip, S Haque, J Harmanen, R Hudec, G Hurst, KM Ivarsen, A Joshi, M Kagitani, N Karaman, R Karjalainen, N Kaur, D Koziel-Wierzbowska, E Kuligowska, T Kundera, S Kurowski, A Kvammen, AP LaCluyze, BC Lee, A Liakos, J Lozano de Haro, JP Moore, M Mugrauer, R Naves Nogues, AW Neely, W Ogloza, S Okano, U Pajdosz, JC Pandey, M Perri, G Poyner, J Provencal, T Pursimo, A Raj, B Rajkumar, R Reinthal, T Reynolds, J Saario, S Sadegi, T Sakanoi, JL Salto Gonzalez, Sameer, AO Simon, M Siwak, T Schweyer, FC Soldan Alfaro, E Sonbas, J Strobl, LO Takalo, L Tremosa Espasa, JR Valdes, VV Vasylenko, F Verrecchia, JR Webb, M Yoneda, M Zejmo, W Zheng, P Zielinski, J Janik, V Chavushyan, I Mohammed, CC Cheung, M Giroletti. 2018. "Stochastic Modeling of Multiwavelength Variability of the Classical BL Lac Object OJ287 on Timescales Ranging from Decades to Hours." ASTROPHYSICAL JOURNAL, Volume 863, Issue 2, pp. ? - ? (20). https://doi.org/10.3847/1538-4357/aad2de
Abstract
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 γ-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 ~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 γ-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 ~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.