Quasi-periodic behaviour in the optical and γ-ray light curves of blazars 3C 66A and B2 1633+38
Abstract
ABSTRACT We report on quasi-periodic variability found in two blazars included in the Steward Observatory Blazar Monitoring data sample: the BL Lac object 3C 66A and the Flat Spectrum Radio Quasar B2 1633+38. We collect optical photometric and polarimetric data in V and R bands of these sources from different observatories: St. Petersburg University, Crimean Astrophysical Observatory, WEBT–GASP, Catalina Real-Time Transient Survey, Steward Observatory, STELLA Robotic Observatory, and Katzman Automatic Imaging Telescope. In addition, an analysis of the γ-ray light curves from Fermi–LAT is included. Three methods are used to search for any periodic behaviour in the data: the Z-transform Discrete Correlation Function, the Lomb–Scargle periodogram and the Weighted Wavelet Z-transform. We find pieces of evidence of possible quasi-periodic variability in the optical photometric data of both sources with periods of ∼3 yr for 3C 66A and ∼1.9 yr for B2 1633+38, with significances between 3σ and 5σ. Only B2 1633+38 shows evidence of this behaviour in the optical polarized data set at a confidence level of 2σ–4σ. This is the first reported evidence of quasi-periodic behaviour in the optical light curve of B2 1633+38. Also, a hint of quasi-periodic behaviour is found in the γ-ray light curve of B2 1633+38 withmore »
- Authors:
-
[1];
[2];
[3];
more »
- Instituto de Astrofísica de Canarias (IAC), E-38200 La Laguna, Tenerife, Spain, Departamento de Astrofísica, Universidad de La Laguna (ULL), E-38206 La Laguna, Tenerife, Spain
- INAF-Osservatorio Astrofisico di Torino, via Osservatorio 20, I-10025 Pino Torinese, Italy
- Astronomical Institute, St Petersburg State University, Universitetskij Pr. 28, Petrodvorets, 198504 St Petersburg, Russia, Pulkovo Astronomical Observatory of RAS, Pulkovskoye shosse 60, 196149 St Petersburg, Russia
- IPARCOS and Department of EMFTEL, Universidad Complutense de Madrid, E-28040 Madrid, Spain
- Steward Observatory, University of Arizona, Tucson, AZ 85721, USA
- Facultad de Ciencias, Universidad de La Laguna (ULL), E-38206 La Laguna, Tenerife, Spain
- Crimean Astrophysical Observatory, P/O Nauchny, 298409 Crimea
- Departamento de Astrofísica, Universidad de La Laguna (ULL), E-38206 La Laguna, Tenerife, Spain, School of Physics & Astronomy, University of Southampton, Highfield, SO17 1BJ Southampton, UK
- Astronomical Institute, St Petersburg State University, Universitetskij Pr. 28, Petrodvorets, 198504 St Petersburg, Russia
- Publication Date:
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 1598907
- Grant/Contract Number:
- AC02-76SF00515; NNX08AW56G; NNX09AU10G; NNX12AO93G; NNX15AU81G
- Resource Type:
- Published Article
- Journal Name:
- Monthly Notices of the Royal Astronomical Society
- Additional Journal Information:
- Journal Name: Monthly Notices of the Royal Astronomical Society Journal Volume: 492 Journal Issue: 4; Journal ID: ISSN 0035-8711
- Publisher:
- Oxford University Press
- Country of Publication:
- United Kingdom
- Language:
- English
Citation Formats
Otero-Santos, J., Acosta-Pulido, J. A., Becerra González, J., Raiteri, C. M., Larionov, V. M., Peñil, P., Smith, P. S., Ballester Niebla, C., Borman, G. A., Carnerero, M. I., Castro Segura, N., Grishina, T. S., Kopatskaya, E. N., Larionova, E. G., Morozova, D. A., Nikiforova, A. A., Savchenko, S. S., Troitskaya, Yu V., Troitsky, I. S., Vasilyev, A. A., and Villata, M. Quasi-periodic behaviour in the optical and γ-ray light curves of blazars 3C 66A and B2 1633+38. United Kingdom: N. p., 2020.
Web. doi:10.1093/mnras/staa134.
Otero-Santos, J., Acosta-Pulido, J. A., Becerra González, J., Raiteri, C. M., Larionov, V. M., Peñil, P., Smith, P. S., Ballester Niebla, C., Borman, G. A., Carnerero, M. I., Castro Segura, N., Grishina, T. S., Kopatskaya, E. N., Larionova, E. G., Morozova, D. A., Nikiforova, A. A., Savchenko, S. S., Troitskaya, Yu V., Troitsky, I. S., Vasilyev, A. A., & Villata, M. Quasi-periodic behaviour in the optical and γ-ray light curves of blazars 3C 66A and B2 1633+38. United Kingdom. doi:10.1093/mnras/staa134.
Otero-Santos, J., Acosta-Pulido, J. A., Becerra González, J., Raiteri, C. M., Larionov, V. M., Peñil, P., Smith, P. S., Ballester Niebla, C., Borman, G. A., Carnerero, M. I., Castro Segura, N., Grishina, T. S., Kopatskaya, E. N., Larionova, E. G., Morozova, D. A., Nikiforova, A. A., Savchenko, S. S., Troitskaya, Yu V., Troitsky, I. S., Vasilyev, A. A., and Villata, M. Thu .
"Quasi-periodic behaviour in the optical and γ-ray light curves of blazars 3C 66A and B2 1633+38". United Kingdom. doi:10.1093/mnras/staa134.
@article{osti_1598907,
title = {Quasi-periodic behaviour in the optical and γ-ray light curves of blazars 3C 66A and B2 1633+38},
author = {Otero-Santos, J. and Acosta-Pulido, J. A. and Becerra González, J. and Raiteri, C. M. and Larionov, V. M. and Peñil, P. and Smith, P. S. and Ballester Niebla, C. and Borman, G. A. and Carnerero, M. I. and Castro Segura, N. and Grishina, T. S. and Kopatskaya, E. N. and Larionova, E. G. and Morozova, D. A. and Nikiforova, A. A. and Savchenko, S. S. and Troitskaya, Yu V. and Troitsky, I. S. and Vasilyev, A. A. and Villata, M.},
abstractNote = {ABSTRACT We report on quasi-periodic variability found in two blazars included in the Steward Observatory Blazar Monitoring data sample: the BL Lac object 3C 66A and the Flat Spectrum Radio Quasar B2 1633+38. We collect optical photometric and polarimetric data in V and R bands of these sources from different observatories: St. Petersburg University, Crimean Astrophysical Observatory, WEBT–GASP, Catalina Real-Time Transient Survey, Steward Observatory, STELLA Robotic Observatory, and Katzman Automatic Imaging Telescope. In addition, an analysis of the γ-ray light curves from Fermi–LAT is included. Three methods are used to search for any periodic behaviour in the data: the Z-transform Discrete Correlation Function, the Lomb–Scargle periodogram and the Weighted Wavelet Z-transform. We find pieces of evidence of possible quasi-periodic variability in the optical photometric data of both sources with periods of ∼3 yr for 3C 66A and ∼1.9 yr for B2 1633+38, with significances between 3σ and 5σ. Only B2 1633+38 shows evidence of this behaviour in the optical polarized data set at a confidence level of 2σ–4σ. This is the first reported evidence of quasi-periodic behaviour in the optical light curve of B2 1633+38. Also, a hint of quasi-periodic behaviour is found in the γ-ray light curve of B2 1633+38 with a confidence level ≥2σ, while no periodicity is observed for 3C 66A in this energy range. We propose different jet emission models that could explain the quasi-periodic variability and the differences found between these two sources.},
doi = {10.1093/mnras/staa134},
journal = {Monthly Notices of the Royal Astronomical Society},
number = 4,
volume = 492,
place = {United Kingdom},
year = {2020},
month = {1}
}
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DOI: 10.1093/mnras/staa134
DOI: 10.1093/mnras/staa134
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Works referenced in this record:
Redshift limits of BL Lacertae objects from optical spectroscopy
journal, November 2007
- Finke, J. D.; Shields, J. C.; Böttcher, M.
- Astronomy & Astrophysics, Vol. 477, Issue 2
Unified Schemes for Radio-Loud Active Galactic Nuclei
journal, June 1995
- Urry, C. Megan; Padovani, Paolo
- Publications of the Astronomical Society of the Pacific, Vol. 107
Quasi-Periodicities at Year-Like Timescales in Blazars
journal, February 2016
- Sandrinelli, A.; Covino, S.; Dotti, M.
- The Astronomical Journal, Vol. 151, Issue 3
Constructing a pulsar timing array
journal, September 1990
- Foster, R. S.; Backer, D. C.
- The Astrophysical Journal, Vol. 361
The Outburst of the Blazar s5 0716+71 in 2011 October: Shock in a Helical jet
journal, April 2013
- Larionov, V. M.; Jorstad, S. G.; Marscher, A. P.
- The Astrophysical Journal, Vol. 768, Issue 1
The 65 Day Period in 3C 66A during Bright State
journal, August 1999
- Lainela, M.; Takalo, L. O.; Sillanpaa, A.
- The Astrophysical Journal, Vol. 521, Issue 2
The power of blazar jets: The power of blazar jets
journal, February 2008
- Celotti, Annalisa; Ghisellini, Gabriele
- Monthly Notices of the Royal Astronomical Society, Vol. 385, Issue 1
Multifrequency Spectra of EXOSAT Blazars
journal, September 1995
- Ghosh, K. K.; Soundararajaperumal, S.
- The Astrophysical Journal Supplement Series, Vol. 100
Redshift determination of the BL Lac object 3C 66A by the detection of its host galaxy cluster at z = 0.340 ★
journal, October 2017
- Torres-Zafra, Juanita; Cellone, Sergio A.; Buzzoni, Alberto
- Monthly Notices of the Royal Astronomical Society, Vol. 474, Issue 3
Detection of Possible Quasi-Periodic Oscillations in the Long-Term Optical Light Curve of the bl lac Object oj 287
journal, November 2016
- Bhatta, G.; Zola, S.; Stawarz, Ł.
- The Astrophysical Journal, Vol. 832, Issue 1
OJ 287 Outburst Structure and a Binary Black Hole Model
journal, March 1996
- Lehto, Harry J.; Valtonen, Mauri J.
- The Astrophysical Journal, Vol. 460
SIMILARITY OF THE OPTICAL-INFRARED AND γ-RAY TIME VARIABILITY OF FERMI BLAZARS
journal, April 2012
- Chatterjee, Ritaban; Bailyn, C. D.; Bonning, E. W.
- The Astrophysical Journal, Vol. 749, Issue 2
Statistical analyses of long-term variability of AGN at high radio frequencies
journal, May 2007
- Hovatta, T.; Tornikoski, M.; Lainela, M.
- Astronomy & Astrophysics, Vol. 469, Issue 3
A possible close supermassive black-hole binary in a quasar with optical periodicity
journal, January 2015
- Graham, Matthew J.; Djorgovski, S. G.; Stern, Daniel
- Nature, Vol. 518, Issue 7537
THE THIRD CATALOG OF ACTIVE GALACTIC NUCLEI DETECTED BY THE FERMI LARGE AREA TELESCOPE
journal, August 2015
- Ackermann, M.; Ajello, M.; Atwood, W. B.
- The Astrophysical Journal, Vol. 810, Issue 1
MULTIWAVELENGTH VARIABILITY PROPERTIES OF FERMI BLAZAR S5 0716+714
journal, February 2014
- Liao, N. H.; Bai, J. M.; Liu, H. T.
- The Astrophysical Journal, Vol. 783, Issue 2
Quasi-periodicities of BL Lacertae objects
journal, July 2018
- Sandrinelli, A.; Covino, S.; Treves, A.
- Astronomy & Astrophysics, Vol. 615
Polarized Radio Outbursts in Bl-Lacertae - Part Two - the Flux and Polarization of a Piston-Driven Shock
journal, November 1985
- Hughes, P. A.; Aller, H. D.; Aller, M. F.
- The Astrophysical Journal, Vol. 298
The STELLA robotic observatory
journal, October 2004
- Strassmeier, K. G.; Granzer, T.; Weber, M.
- Astronomische Nachrichten, Vol. 325, Issue 6-8
A model for periodic blazars
journal, October 2016
- Sobacchi, Emanuele; Sormani, Mattia C.; Stamerra, Antonio
- Monthly Notices of the Royal Astronomical Society, Vol. 465, Issue 1
Efficient generation of jets from magnetically arrested accretion on a rapidly spinning black hole: Jets from magnetically arrested BH accretion
journal, November 2011
- Tchekhovskoy, Alexander; Narayan, Ramesh; McKinney, Jonathan C.
- Monthly Notices of the Royal Astronomical Society: Letters, Vol. 418, Issue 1
Variability of Gamma-Ray Emission from Blazars on Black hole Timescales
journal, April 2013
- Vovk, Ie.; Neronov, A.
- The Astrophysical Journal, Vol. 767, Issue 2
High-resolution 3D relativistic MHD simulations of jets: 3D RMHD simulations of jets
journal, January 2010
- Mignone, A.; Rossi, P.; Bodo, G.
- Monthly Notices of the Royal Astronomical Society, Vol. 402, Issue 1
Searches for Supermassive Back Hole Binaries
journal, December 2006
- Hudec, R.; Basta, M.
- Chinese Journal of Astronomy and Astrophysics, Vol. 6, Issue S1
Temporal correlation between the optical and γ-ray flux variations in the blazar 3C 454.3
journal, April 2019
- Rajput, Bhoomika; Stalin, C. S.; Sahayanathan, S.
- Monthly Notices of the Royal Astronomical Society, Vol. 486, Issue 2
Revisiting Quasi-periodic Modulation in γ -Ray Blazar PKS 2155-304 with Fermi Pass 8 Data
journal, February 2017
- Zhang, Peng-fei; Yan, Da-hai; Liao, Neng-hui
- The Astrophysical Journal, Vol. 835, Issue 2
Multiwavelength behaviour of the blazar OJ 248 from radio to γ-rays★
journal, May 2015
- Carnerero, M. I.; Raiteri, C. M.; Villata, M.
- Monthly Notices of the Royal Astronomical Society, Vol. 450, Issue 3
Generating artificial light curves: revisited and updated
journal, June 2013
- Emmanoulopoulos, D.; McHardy, I. M.; Papadakis, I. E.
- Monthly Notices of the Royal Astronomical Society, Vol. 433, Issue 2
Radio and optical intra-day variability observations of five blazars
journal, May 2017
- Liu, X.; Yang, P. P.; Liu, J.
- Monthly Notices of the Royal Astronomical Society, Vol. 469, Issue 2
Multi-Wavelength Intra-Day Variability and Quasi-Periodic Oscillation in Blazars
journal, December 2017
- Gupta, Alok
- Galaxies, Vol. 6, Issue 1
On the Redshift of the very high Energy Blazar 3c 66a
journal, March 2013
- Furniss, A.; Fumagalli, M.; Danforth, C.
- The Astrophysical Journal, Vol. 766, Issue 1
A method for the estimation of the significance of cross-correlations in unevenly sampled red-noise time series
journal, September 2014
- Max-Moerbeck, W.; Richards, J. L.; Hovatta, T.
- Monthly Notices of the Royal Astronomical Society, Vol. 445, Issue 1
2FHL: THE SECOND CATALOG OF HARD FERMI -LAT SOURCES
journal, January 2016
- Ackermann, M.; Ajello, M.; Atwood, W. B.
- The Astrophysical Journal Supplement Series, Vol. 222, Issue 1
General relativistic magnetohydrodynamic simulations of magnetically choked accretion flows around black holes: Magnetically choked accretion flows
journal, June 2012
- McKinney, Jonathan C.; Tchekhovskoy, Alexander; Blandford, Roger D.
- Monthly Notices of the Royal Astronomical Society, Vol. 423, Issue 4
Understanding the Lomb–Scargle Periodogram
journal, May 2018
- VanderPlas, Jacob T.
- The Astrophysical Journal Supplement Series, Vol. 236, Issue 1
Progress in Multi-wavelength and Multi-Messenger Observations of Blazars and Theoretical Challenges
journal, January 2019
- Böttcher, Markus
- Galaxies, Vol. 7, Issue 1
Wavelets for period analysis of unevenly sampled time series
journal, October 1996
- Foster, Grant
- The Astronomical Journal, Vol. 112
Turbulent, Extreme Multi-Zone Model for Simulating flux and Polarization Variability in Blazars
journal, December 2013
- Marscher, Alan P.
- The Astrophysical Journal, Vol. 780, Issue 1
The awakening of BL Lacertae: observations by Fermi, Swift and the GASP-WEBT★
journal, October 2013
- Raiteri, C. M.; Villata, M.; D'Ammando, F.
- Monthly Notices of the Royal Astronomical Society, Vol. 436, Issue 2
A kinematic study of the compact jet in quasar B3 1633+382
journal, October 2010
- Liu, Y.; Jiang, D. R.; Shen, Z. -Q.
- Astronomy & Astrophysics, Vol. 522
Blazar spectral variability as explained by a twisted inhomogeneous jet
journal, December 2017
- Raiteri, C. M.; Villata, M.; Acosta-Pulido, J. A.
- Nature, Vol. 552, Issue 7685
Extragalactic Jets: the high Energy view
conference, June 2012
- Tavecchio, F.
- Proceedings of the MG10 Meeting held at Brazilian Center for Research in Physics (CBPF), The Tenth Marcel Grossmann Meeting
Gamma-Ray Astrophysics in the Time Domain
journal, January 2019
- Rieger, Frank
- Galaxies, Vol. 7, Issue 1
Studies in astronomical time series analysis. II - Statistical aspects of spectral analysis of unevenly spaced data
journal, December 1982
- Scargle, J. D.
- The Astrophysical Journal, Vol. 263
Robust Locally Weighted Regression and Smoothing Scatterplots
journal, December 1979
- Cleveland, William S.
- Journal of the American Statistical Association, Vol. 74, Issue 368
Periodic Structure in the Megaparsec-Scale jet of pks 0637–752
journal, September 2012
- Godfrey, L. E. H.; Lovell, J. E. J.; Burke-Spolaor, S.
- The Astrophysical Journal, Vol. 758, Issue 2
Optical photometric monitoring of γ -ray loud
blazars. : I. Observations from November 1994 to November 1995
journal, January 1997
- Villata, M.; Raiteri, C. M.; Ghisellini, G.
- Astronomy and Astrophysics Supplement Series, Vol. 121, Issue 1
Optical Photometric Monitoring for 3C 66A during 1996–2009 and Its Periodicity Analysis
journal, January 2018
- Fan, J. H.; Tao, J.; Liu, Y.
- The Astronomical Journal, Vol. 155, Issue 2
THE LARGE AREA TELESCOPE ON THE FERMI GAMMA-RAY SPACE TELESCOPE MISSION
journal, May 2009
- Atwood, W. B.; Abdo, A. A.; Ackermann, M.
- The Astrophysical Journal, Vol. 697, Issue 2
Blazar Jets Perturbed by Magneto-gravitational Stresses in Supermassive Binaries
journal, February 2017
- Cavaliere, A.; Tavani, M.; Vittorini, V.
- The Astrophysical Journal, Vol. 836, Issue 2
Least-squares frequency analysis of unequally spaced data
journal, February 1976
- Lomb, N. R.
- Astrophysics and Space Science, Vol. 39, Issue 2
Multiwavelength monitoring of the BL Lacertae object PKS 2155-304. 4: Multiwavelength analysis
journal, January 1995
- Edelson, R.; Krolik, J.; Madejski, G.
- The Astrophysical Journal, Vol. 438
The Katzman Automatic Imaging Telescope Gamma‐Ray Burst Alert System, and Observations of GRB 020813
journal, July 2003
- Li, Weidong; Filippenko, Alexei V.; Chornock, Ryan
- Publications of the Astronomical Society of the Pacific, Vol. 115, Issue 809
Measuring the rotation period distribution of field M dwarfs with Kepler
journal, April 2013
- McQuillan, A.; Aigrain, S.; Mazeh, T.
- Monthly Notices of the Royal Astronomical Society, Vol. 432, Issue 2
A γ -ray Quasi-periodic Modulation in the Blazar PKS 0301–243?
journal, August 2017
- Zhang, Peng-Fei; Yan, Da-Hai; Zhou, Jia-Neng
- The Astrophysical Journal, Vol. 845, Issue 1
Multi-Wavelength Observations of the Flaring Gamma-Ray Blazar 3c 66a in 2008 October
journal, December 2010
- Abdo, A. A.; Ackermann, M.; Ajello, M.
- The Astrophysical Journal, Vol. 726, Issue 1
Another look at the BL Lacertae flux and spectral variability: Observations by GASP-WEBT, XMM-
journal, November 2010
- Raiteri, C. M.; Villata, M.; Bruschini, L.
- Astronomy & Astrophysics, Vol. 524
The Doppler crisis in TeV blazars and its possible resolutions
conference, December 2017
- Piner, B. Glenn; Edwards, Philip G.
- Proceedings of the MG14 Meeting on General Relativity, The Fourteenth Marcel Grossmann Meeting
Observations of the Blazar 3c 66a with the Magic Telescopes in Stereoscopic mode
journal, December 2010
- Aleksić, J.; Antonelli, L. A.; Antoranz, P.
- The Astrophysical Journal, Vol. 726, Issue 2
Kinematics of Parsec-scale Jets of Gamma-Ray Blazars at 43 GHz within the VLBA-BU-BLAZAR Program
journal, September 2017
- Jorstad, Svetlana G.; Marscher, Alan P.; Morozova, Daria A.
- The Astrophysical Journal, Vol. 846, Issue 2
Models for high-frequency radio outbursts in extragalactic sources, with application to the early 1983 millimeter-to-infrared flare of 3C 273
journal, November 1985
- Marscher, A. P.; Gear, W. K.
- The Astrophysical Journal, Vol. 298
First Results from the Catalina Real-Time Transient Survey
journal, April 2009
- Drake, A. J.; Djorgovski, S. G.; Mahabal, A.
- The Astrophysical Journal, Vol. 696, Issue 1
Veritas Observations of a very high Energy γ-Ray Flare from the Blazar 3c 66a
journal, February 2009
- Acciari, V. A.; Aliu, E.; Arlen, T.
- The Astrophysical Journal, Vol. 693, Issue 2
Jet Precession Driven by a Supermassive Black Hole Binary System in the BL Lac Object PG 1553+113
journal, December 2017
- Caproni, Anderson; Abraham, Zulema; Motter, Juliana Cristina
- The Astrophysical Journal, Vol. 851, Issue 2
Pulsar timing constraints on the Fermi massive black hole binary blazar population
journal, August 2018
- Holgado, A. Miguel; Sesana, Alberto; Sandrinelli, Angela
- Monthly Notices of the Royal Astronomical Society: Letters, Vol. 481, Issue 1
General Relativistic Magnetohydrodynamic Simulations of the hard State as a Magnetically Dominated Accretion flow
journal, March 2009
- Fragile, P. Chris; Meier, David L.
- The Astrophysical Journal, Vol. 693, Issue 1
Kinematics of and Emission from Helically Orbiting Blobs in a Relativistic Magnetized jet
journal, May 2015
- Mohan, P.; Mangalam, A.
- The Astrophysical Journal, Vol. 805, Issue 2
Multiwavelength Evidence for Quasi-Periodic Modulation in the Gamma-Ray Blazar pg 1553+113
journal, November 2015
- Ackermann, M.; Ajello, M.; Albert, A.
- The Astrophysical Journal, Vol. 813, Issue 2
Helical jets in blazars: Interpretation of the multifrequency long-term variability of AO 0235+16
journal, May 2004
- Ostorero, L.; Villata, M.; Raiteri, C. M.
- Astronomy & Astrophysics, Vol. 419, Issue 3
A simple test for periodic signals in red noise
journal, February 2005
- Vaughan, S.
- Astronomy & Astrophysics, Vol. 431, Issue 1
Variability of the Blazar 4C 38.41 in 2006–2017
journal, May 2019
- Hagen-Thorn, V. A.; Troitskaya, Yu. V.; Hagen-Thorn, E. I.
- Astronomy Reports, Vol. 63, Issue 5
On the Redshift of TeV BL Lac Objects
journal, March 2017
- Paiano, Simona; Landoni, Marco; Falomo, Renato
- The Astrophysical Journal, Vol. 837, Issue 2
The Sloan Digital Sky Survey Quasar Catalog: Twelfth data release
journal, January 2017
- Pâris, Isabelle; Petitjean, Patrick; Ross, Nicholas P.
- Astronomy & Astrophysics, Vol. 597
Polarization and structure of relativistic parsec-scale AGN jets
journal, July 2005
- Lyutikov, M.; Pariev, V. I.; Gabuzda, D. C.
- Monthly Notices of the Royal Astronomical Society, Vol. 360, Issue 3
OJ 287 - Binary pair of supermassive black holes
journal, February 1988
- Sillanpaa, A.; Haarala, S.; Valtonen, M. J.
- The Astrophysical Journal, Vol. 325
Testing the Binary Hypothesis: Pulsar Timing Constraints on Supermassive Black Hole Binary Candidates
journal, March 2018
- Sesana, Alberto; Haiman, Zoltán; Kocsis, Bence
- The Astrophysical Journal, Vol. 856, Issue 1
Compton Dominance and the Blazar Sequence
journal, January 2013
- Finke, Justin D.
- The Astrophysical Journal, Vol. 763, Issue 2
Variability of the blazar 4C 38.41 (B3 1633+382) from GHz frequencies to GeV energies
journal, September 2012
- Raiteri, C. M.; Villata, M.; Smith, P. S.
- Astronomy & Astrophysics, Vol. 545
The GASP-WEBT monitoring of 3C 454.3 during the 2008 optical-to-radio and γ-ray outburst
journal, August 2009
- Villata, M.; Raiteri, C. M.; Gurwell, M. A.
- Astronomy & Astrophysics, Vol. 504, Issue 3
Periodic radio variabilities of the blazar 1156+295: harmonic oscillations
journal, July 2014
- Wang, Jun-Yi; An, Tao; Baan, Willem A.
- Monthly Notices of the Royal Astronomical Society, Vol. 443, Issue 1
On the Geometrical Origin of Periodicity in Blazar-type Sources
journal, September 2004
- Rieger, Frank M.
- The Astrophysical Journal, Vol. 615, Issue 1
Coordinated Multiwavelength Observation of 3C 66A during the WEBT Campaign of 2003–2004
journal, September 2005
- Bottcher, M.; Harvey, J.; Joshi, M.
- The Astrophysical Journal, Vol. 631, Issue 1
Temporal evolution of long-timescale periodicities in ULX NGC 5408 X-1
journal, December 2015
- An, Tao; Lu, Xiang-Long; Wang, Jun-Yi
- Astronomy & Astrophysics, Vol. 585
The Whole Earth Blazar Telescope Campaign on the Intermediate bl lac Object 3c 66a in 2007-2008
journal, March 2009
- Böttcher, M.; Fultz, K.; Aller, H. D.
- The Astrophysical Journal, Vol. 694, Issue 1
Radio Variability Properties of a Sample of 168 Radio Sources: Periodicity Analysis
journal, October 2006
- Fan, J. H.; Liu, Y.; Yuan, Y. H.
- Chinese Journal of Astronomy and Astrophysics, Vol. 6, Issue S2
Gamma-ray quasi-periodicities of blazars. A cautious approach
journal, October 2018
- Covino, S.; Sandrinelli, A.; Treves, A.
- Monthly Notices of the Royal Astronomical Society, Vol. 482, Issue 1
The magnetic field structure in CTA 102 from high-resolution mm-VLBI observations during the flaring state in 2016–2017
journal, February 2019
- Casadio, Carolina; Marscher, Alan P.; Jorstad, Svetlana G.
- Astronomy & Astrophysics, Vol. 622
Correlated Multi–Wave Band Variability in the Blazar 3C 279 from 1996 to 2007
journal, December 2008
- Chatterjee, Ritaban; Jorstad, Svetlana G.; Marscher, Alan P.
- The Astrophysical Journal, Vol. 689, Issue 1
Holocene climate variability on millennial scales recorded in Greenland ice cores
journal, January 2005
- Witt, A.; Schumann, A. Y.
- Nonlinear Processes in Geophysics, Vol. 12, Issue 3
Correlated Variability in the Blazar 3c 454.3
journal, May 2009
- Bonning, E. W.; Bailyn, C.; Urry, C. M.
- The Astrophysical Journal, Vol. 697, Issue 2