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Multiwavelength behaviour of the blazar 3C 279: decade-long study from γ-ray to radio

Larionov, V. M. and Jorstad, S. G. and Marscher, A. P. and Villata, M. and Raiteri, C. M. and Smith, P. S. and Agudo, I. and Savchenko, S. S. and Morozova, D. A. and Acosta-Pulido, J. A. and Aller, M. F. and Aller, H. D. and Andreeva, T. S. and Arkharov, A. A. and Bachev, R. and Bonnoli, G. and Borman, G. A. and Bozhilov, V. and Calcidese, P. and Carnerero, M. I. and Carosati, D. and Casadio, C. and Chen, W.-P. and Damljanovic, G. and Dementyev, A. V. and Di Paola, A. and Frasca, A. and Fuentes, A. and Gómez, J. L. and Gónzalez-Morales, P. and Giunta, A. and Grishina, T. S. and Gurwell, M. A. and Hagen-Thorn, V. A. and Hovatta, T. and Ibryamov, S. and Joshi, M. and Kiehlmann, S. and Kim, J.-Y. and Kimeridze, G. N. and Kopatskaya, E. N. and Kovalev, Yu. A. and Kovalev, Y. Y. and Kurtanidze, O. M. and Kurtanidze, S. O. and Lähteenmäki, A. and Lázaro, C. and Larionova, L. V. and Larionova, E. G. and Leto, G. and Marchini, A. and Matsumoto, K. and Mihov, B. and Minev, M. and Mingaliev, M. G. and Mirzaqulov, D. and Muñoz Dimitrova, R. V. and Myserlis, I. and Nikiforova, A. A. and Nikolashvili, M. G. and Nizhelsky, N. A. and Ovcharov, E. and Pressburger, L. D. and Rakhimov, I. A. and Righini, S. and Rizzi, N. and Sadakane, K. and Sadun, A. C. and Samal, M. R. and Sanchez, R. Z. and Semkov, E. and Sergeev, S. G. and Sigua, L. A. and Slavcheva-Mihova, L. and Sola, P. and Sotnikova, Yu. V. and Strigachev, A. and Thum, C. and Traianou, E. and Troitskaya, Yu. V. and Troitsky, I. S. and Tsybulev, P. G. and Vasilyev, A. A. and Vince, O. and Weaver, Z. R. and Williamson, K. E. and Zhekanis, G. V. (2020) Multiwavelength behaviour of the blazar 3C 279: decade-long study from γ-ray to radio. Monthly Notices of the Royal Astronomical Society, 492 (3). pp. 3829-3848. ISSN 0035-8711.

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We report the results of decade-long (2008–2018) γ-ray to 1 GHz radio monitoring of the blazar 3C 279, including GASP/WEBT, Fermi and Swift data, as well as polarimetric and spectroscopic data. The X-ray and γ-ray light curves correlate well, with no delay ≳3 h, implying general cospatiality of the emission regions. The γ-ray–optical flux–flux relation changes with activity state, ranging from a linear to a more complex dependence. The behaviour of the Stokes parameters at optical and radio wavelengths, including 43 GHz Very Long Baseline Array images, supports either a predominantly helical magnetic field or motion of the radiating plasma along a spiral path. Apparent speeds of emission knots range from 10 to 37c, with the highest values requiring bulk Lorentz factors close to those needed to explain γ-ray variability on very short time-scales. The Mg II emission line flux in the ‘blue’ and ‘red’ wings correlates with the optical synchrotron continuum flux density, possibly providing a variable source of seed photons for inverse Compton scattering. In the radio bands, we find progressive delays of the most prominent light-curve maxima with decreasing frequency, as expected from the frequency dependence of the τ = 1 surface of synchrotron self-absorption. The global maximum in the 86 GHz light curve becomes less prominent at lower frequencies, while a local maximum, appearing in 2014, strengthens toward decreasing frequencies, becoming pronounced at ∼5 GHz. These tendencies suggest different Doppler boosting of stratified radio-emitting zones in the jet.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Larionov, V. M.0000-0002-4640-4356
Jorstad, S. G.0000-0001-6158-1708
Raiteri, C. M.0000-0003-1784-2784
Ibryamov, S.0000-0002-4618-1201
Kiehlmann, S.0000-0001-6314-9177
Kovalev, Yu. A.0000-0001-9303-3263
Marchini, A.0000-0003-3779-6762
Myserlis, I.0000-0003-3025-9497
Samal, M. R.0000-0002-9431-6297
Weaver, Z. R.0000-0001-6314-0690
Additional Information:© 2020 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model ( Received: 03 October 2019; Revision received: 12 December 2019; Accepted: 08 January 2020; Published: 11 January 2020. We thank the referee for attentive reading and comments that helped to improve presentation of the manuscript. The data collected by the WEBT collaboration are stored in the WEBT archive at the Osservatorio Astrofisico di Torino – INAF (; for questions regarding their availability, please contact the WEBT President Massimo Villata ( The St. Petersburg University team acknowledges support from Russian Science Foundation grant 17-12-01029. The research at BU was supported in part by National Science Foundation grant AST-1615796 and NASA Fermi Guest Investigator grants 80NSSC17K0649, 80NSSC19K1504, and 80NSSC19K1505. The PRISM camera at Lowell Observatory was developed by K. Janes et al. at BU and Lowell Observatory, with funding from the NSF, BU, and Lowell Observatory. The emission-line observations made use of the DCT at Lowell Observatory, supported by Discovery Communications, Inc., BU, the University of Maryland, the University of Toledo, and Northern Arizona University. The VLBA is an instrument of the National Radio Astronomy Observatory. The National Radio Astronomy Observatory is a facility of the US NSF, operated under cooperative agreement by Associated Universities, Inc. This research has used data from the UMRAO which was supported by the University of Michigan; research at this facility was supported by NASA under awards NNX09AU16G, NNX10AP16G, NNX11AO13G, and NNX13AP18G, and by the NSF under award AST-0607523. The Steward Observatory spectropolarimetric monitoring project was supported by NASA Fermi Guest Investigator grants NNX08AW56G, NNX09AU10G, NNX12AO93G, and NNX15AU81G. The Torino group acknowledges financial contribution from agreement ASI-INAF n.2017-14-H.0 and from contract PRIN-SKA-CTA-INAF 2016. I.A. acknowledges support by a Ramón y Cajal grant (RYC-2013-14511) of the ‘Ministerio de Ciencia, Innovación, y Universidades (MICIU)’ of Spain and from MCIU through the ‘Center of Excellence Severo Ochoa’ award for the Instituto de Astrofísica de Andalucía-CSIC (SEV-2017-0709). Acquisition and reduction of the POLAMI and MAPCAT data were supported by MICIU through grant AYA2016-80889-P. The POLAMI observations were carried out at the IRAM 30-m Telescope, supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain). The MAPCAT observations were carried out at the German-Spanish Calar Alto Observatory, jointly operated by the Max-Plank-Institut für Astronomie and the Instituto de Astrofísica de Andalucía-CSIC. The study is based partly on data obtained with the STELLA robotic telescopes in Tenerife, an AIP facility jointly operated by AIP and IAC. The OVRO 40-m monitoring program is supported in part by NASA grants NNX08AW31G, NNX11A043G, and NNX14AQ89G, and NSF grants AST-0808050 and AST-1109911. TH was supported by the Academy of Finland projects 317383 and 320085. AZT-24 observations were made within an agreement between Pulkovo, Rome and Teramo observatories. The Submillimeter Array is a joint project between the Smithsonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy and Astrophysics and is funded by the Smithsonian Institution and the Academia Sinica. The Abastumani team acknowledges financial support by the Shota Rustaveli National Science Foundation under contract FR/217950/16. This research was partially supported by the Bulgarian National Science Fund of the Ministry of Education and Science under grants DN 08-1/2016, DN 18-13/2017, KP-06-H28/3 (2018), and KP-06-PN38/1 (2019), Bulgarian National Science Programme ‘Young Scientists and Postdoctoral Students 2019’, Bulgarian National Science Fund under grant DN18-10/2017 and National RI Roadmap Projects DO1-157/28.08.2018 and DO1-153/28.08.2018 of the Ministry of Education and Science of the Republic of Bulgaria. GD and OV gratefully acknowledge observing grant support from the Institute of Astronomy and Rozhen National Astronomical Observatory via bilateral joint research project ‘Study of ICRF radio-sources and fast variable astronomical objects’ (head – G. Damljanovic). This work was partly supported by the National Science Fund of the Ministry of Education and Science of Bulgaria under grant DN 08-20/2016, and by project RD-08-37/2019 of the University of Shumen. This work is a part of projects nos 176011, 176004, and 176021, supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia. MGM acknowledges support through the Russian Government Program of Competitive Growth of Kazan Federal University. The Astronomical Observatory of the Autonomous Region of the Aosta Valley (OAVdA) is managed by the Fondazione Clément Fillietroz-ONLUS, which is supported by the Regional Government of the Aosta Valley, the Town Municipality of Nus and the ‘Unité des Communes valdôtaines Mont-Émilius’. The research at the OAVdA was partially funded by several ‘Research and Education’ annual grants from Fondazione CRT. This article is partly based on observations made with the IAC80 and TCS telescopes operated by the Instituto de Astrofísica de Canarias in the Spanish Observatorio del Teide on the island of Tenerife. A part of the observations were carried out using the RATAN-600 scientific equipment (SAO of the Russian Academy of Sciences).
Funding AgencyGrant Number
Russian Science Foundation17-12-01029
Agenzia Spaziale Italiana (ASI)2017-14-H.0
Istituto Nazionale di Astrofisica (INAF)CTA-INAF 2016
Ramón y Cajal ProgrammeRYC-2013-14511
Severo OchoaSEV-2017-0709
Ministerio de Economía, Industria y Competitividad (MINECO)AYA2016-80889-P
Academy of Finland317383
Academy of Finland320085
Shota Rustaveli National Science FoundationFR/217950/16
Ministry of Education and Science (Bulgaria)DN 08-1/2016
Ministry of Education and Science (Bulgaria)DN 18-13/2017
Ministry of Education and Science (Bulgaria)KP-06-H28/3
Ministry of Education and Science (Bulgaria)KP-06-PN38/1
Bulgarian National Science ProgrammeUNSPECIFIED
Bulgarian National Science FundDN18-10/2017
Ministry of Education and Science (Bulgaria)DO1-157/28.08.2018
Ministry of Education and Science (Bulgaria)DO1-153/28.08.2018
Institute of AstronomyUNSPECIFIED
Rozhen National Astronomical ObservatoryUNSPECIFIED
Ministry of Education and Science (Bulgaria)DN 08-20/2016
University of ShumenRD-08-37/2019
Ministry of Education, Science and Technological Development (Serbia)176011
Ministry of Education, Science and Technological Development (Serbia)176004
Ministry of Education, Science and Technological Development (Serbia)176021
Kazan Federal UniversityUNSPECIFIED
Subject Keywords:methods: observational, techniques: photometric, techniques: polarimetric, techniques: spectroscopic, galaxies: active, quasars: individual: 3C 279
Issue or Number:3
Record Number:CaltechAUTHORS:20200327-073401845
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Official Citation:V M Larionov, S G Jorstad, A P Marscher, M Villata, C M Raiteri, P S Smith, I Agudo, S S Savchenko, D A Morozova, J A Acosta-Pulido, M F Aller, H D Aller, T S Andreeva, A A Arkharov, R Bachev, G Bonnoli, G A Borman, V Bozhilov, P Calcidese, M I Carnerero, D Carosati, C Casadio, W-P Chen, G Damljanovic, A V Dementyev, A Di Paola, A Frasca, A Fuentes, J L Gómez, P Gónzalez-Morales, A Giunta, T S Grishina, M A Gurwell, V A Hagen-Thorn, T Hovatta, S Ibryamov, M Joshi, S Kiehlmann, J-Y Kim, G N Kimeridze, E N Kopatskaya, Yu A Kovalev, Y Y Kovalev, O M Kurtanidze, S O Kurtanidze, A Lähteenmäki, C Lázaro, L V Larionova, E G Larionova, G Leto, A Marchini, K Matsumoto, B Mihov, M Minev, M G Mingaliev, D Mirzaqulov, R V Muñoz Dimitrova, I Myserlis, A A Nikiforova, M G Nikolashvili, N A Nizhelsky, E Ovcharov, L D Pressburger, I A Rakhimov, S Righini, N Rizzi, K Sadakane, A C Sadun, M R Samal, R Z Sanchez, E Semkov, S G Sergeev, L A Sigua, L Slavcheva-Mihova, P Sola, Yu V Sotnikova, A Strigachev, C Thum, E Traianou, Yu V Troitskaya, I S Troitsky, P G Tsybulev, A A Vasilyev, O Vince, Z R Weaver, K E Williamson, G V Zhekanis, Multiwavelength behaviour of the blazar 3C 279: decade-long study from γ-ray to radio, Monthly Notices of the Royal Astronomical Society, Volume 492, Issue 3, March 2020, Pages 3829–3848,
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:102136
Deposited By: Tony Diaz
Deposited On:27 Mar 2020 16:37
Last Modified:27 Mar 2020 16:37

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