Investigating the multiwavelength behaviour of the flat spectrum radio quasar CTA 102 during 2013–2017

Journal Article · 09 October 2019 · Monthly Notices of the Royal Astronomical Society

DOI: https://doi.org/10.1093/mnras/stz2792 · OSTI ID:1576016

D’Ammando, F.  ^[1]; Raiteri, C. M.  ^[2]; Villata, M. ^[2]; Acosta-Pulido, J. A. ^[3]; Agudo, I. ^[4]; Arkharov, A. A. ^[5]; Bachev, R. ^[6]; Baida, G. V. ^[7]; Benítez, E.  ^[8]; Borman, G. A. ^[7]; Boschin, W. ^[9]; Bozhilov, V. ^[10]; Butuzova, M. S.  ^[7]; Calcidese, P. ^[11]; Carnerero, M. I. ^[2]; Carosati, D. ^[12]; Casadio, C. ^[13]; Castro-Segura, N. ^[14]; Chen, W-P ^[15]; Damljanovic, G. ^[16] ; Di Paola, A. ^[17]; Echevarría, J. ^[8]; Efimova, N. V. ^[5]; Ehgamberdiev, Sh A. ^[18]; Espinosa, C. ^[8]; Fuentes, A. ^[4]; Giunta, A. ^[17]; Gómez, J. L. ^[4]; Grishina, T. S. ^[19]; Gurwell, M. A. ^[20]; Hiriart, D. ^[8]; Jermak, H. ^[21]; Jordan, B. ^[22]; Jorstad, S. G. ^[23]; Joshi, M. ^[24]; Kimeridze, G. N. ^[25]; Kopatskaya, E. N. ^[19]; Kuratov, K. ^[26]; Kurtanidze, O. M. ^[27]; Kurtanidze, S. O. ^[25]; Lähteenmäki, A. ^[28]; Larionov, V. M. ^[29]; Larionova, E. G. ^[19]; Larionova, L. V. ^[19]; Lázaro, C. ^[3]; Lin, C. S. ^[15]; Malmrose, M. P. ^[24]; Marscher, A. P. ^[24]; Matsumoto, K. ^[30]; McBreen, B. ^[31]; Michel, R. ^[8]; Mihov, B. ^[6]; Minev, M. ^[10]; Mirzaqulov, D. O. ^[18]; Molina, S. N. ^[4]; Moody, J. W. ^[32]; Morozova, D. A. ^[19]; Nazarov, S. V. ^[7]; Nikiforova, A. A. ^[29]; Nikolashvili, M. G. ^[25]; Ohlert, J. M. ^[33]; Okhmat, N. ^[7]; Ovcharov, E. ^[8]; Pinna, F. ^[3]; Polakis, T. A. ^[34]; Protasio, C. ^[3]; Pursimo, T. ^[35]; Redondo-Lorenzo, F. J. ^[3]; Rizzi, N. ^[36]; Rodriguez-Coira, G. ^[37]; Sadakane, K. ^[30]; Sadun, A. C. ^[38]; Samal, M. R.  ^[15]; Savchenko, S. S. ^[19]; Semkov, E. ^[6]; Sigua, L. ^[25]; Skiff, B. A. ^[39]; Slavcheva-Mihova, L. ^[6]; Smith, P. S. ^[40]; Steele, I. A. ^[21]; Strigachev, A. ^[6]; Tammi, J. ^[41]; Thum, C. ^[42]; Tornikoski, M. ^[41]; Troitskaya, Yu V. ^[19]; Troitsky, I. S. ^[19]; Vasilyev, A. A.  ^[19]; Vince, O. ^[16]; Hovatta, T. ^[43]; Kiehlmann, S.  ^[44]; Max-Moerbeck, W. ^[45]; Readhead, A. C. S. ^[44]; Reeves, R. ^[46]; Pearson, T. J.  ^[44]; Mufakharov, T. ^[47]; Sotnikova, Yu V. ^[48]; Mingaliev, M. G. ^[49]

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1. INAF - Istituto di Radioastronomia, Via Gobetti 101, I-40129 Bologna, Italy
2. INAF - Osservatorio Astrofisico di Torino, Via P. Torinese, I- Torino, Italy
3. Instituto de Astrofisica de Canarias (IAC), La Laguna, E-38200 Tenerife, Spain, Departamento de Astrofisica, Universidad de La Laguna, La Laguna, E-38205 Tenerife, Spain
4. Instituto de Astrofísica de Andalucía (CSIC), E-18080 Granada, Spain
5. Pulkovo Observatory, 196140 St. Petersburg, Russia
6. Institute of Astronomy and NAO, Bulgarian Academy of Sciences, 1784 Sofia, Bulgaria
7. Crimean Astrophysical Observatory RAS, P/O Nauchny 298409, Russia
8. Instituto de Astronomía, Universidad Nacional Autónoma de México, México
9. Instituto de Astrofisica de Canarias (IAC), La Laguna, E-38200 Tenerife, Spain, Departamento de Astrofisica, Universidad de La Laguna, La Laguna, E-38205 Tenerife, Spain, INAF, TNG Fundación Galileo Galilei, E-38712 La Palma, Spain
10. Faculty of Physics, Department of Astronomy, University of Sofia, BG-1164 Sofia, Bulgaria
11. Osservatorio Astronomico della Regione Autonoma Valle d’Aosta, I-11020 Nus, Italy
12. INAF, TNG Fundación Galileo Galilei, E-38712 La Palma, Spain, EPT Observatories, Tijarafe, E-38780 La Palma, Spain
13. Instituto de Astrofísica de Andalucía (CSIC), E-18080 Granada, Spain, Max-Planck-Institut für Radioastronomie, D–53121 Bonn, Germany
14. Departamento de Astrofisica, Universidad de La Laguna, La Laguna, E-38205 Tenerife, Spain, School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ, UK
15. Graduate Institute of Astronomy, National Central University, Jhongli City, Taoyuan County 32001, Taiwan
16. Astronomical Observatory, 11060 Belgrade, Serbia
17. INAF, Osservatorio Astronomico di Roma, I-00040 Monte Porzio Catone, Italy
18. Ulugh Beg Astronomical Institute, Maidanak Observatory, Tashkent 100052, Uzbekistan
19. Astronomical Institute, St. Petersburg State University, 198504 St. Petersburg, Russia
20. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 USA
21. Astrophysics Research Institute, Liverpool John Moores University, Liverpool L3 5RF, UK
22. School of Cosmic Physics, Dublin Institute For Advanced Studies, Ireland
23. Astronomical Institute, St. Petersburg State University, 198504 St. Petersburg, Russia, Institute for Astrophysical Research, Boston University, Boston, MA 02215, USA
24. Institute for Astrophysical Research, Boston University, Boston, MA 02215, USA
25. Abastumani Observatory, Mt. Kanobili, 0301 Abastumani, Georgia
26. NNLOT, Al-Farabi Kazakh National University, 050040 Almaty, Kazakhstan, Fesenkov Astrophysical Institute, Almaty, Kazakhstan
27. Abastumani Observatory, Mt. Kanobili, 0301 Abastumani, Georgia, Engelhardt Astronomical Observatory, Kazan Federal University, 422526 Tatarstan, Russia, Landessternwarte, Zentrum fr Astronomie der Universitt Heidelberg, D-69117 Heidelberg, Germany, Center for Astrophysics, Guangzhou University, Guangzhou 510006, China
28. Aalto University Metsähovi Radio Observatory, FI-02540 Kylmälä, Finland, Aalto University Dept of Electronics and Nanoengineering, FI-00076 Aalto, Finland
29. Pulkovo Observatory, 196140 St. Petersburg, Russia, Astronomical Institute, St. Petersburg State University, 198504 St. Petersburg, Russia
30. Astronomical Institute, Osaka Kyoiku University, Osaka 582-8582, Japan
31. UCD School of Physics, University College Dublin, Dublin 4, Ireland
32. Department of Physics and Astronomy, Brigham Young University, Provo, UT 84602, USA
33. Michael Adrian Observatorium, Astronomie Stiftung Trebur, D-65468 Trebur, Germany, University of Applied Sciences, Technische Hochschule Mittelhessen, D-61169 Friedberg, Germany
34. Command Module Observatory, Tempe AZ, USA
35. Nordic Optical Telescope, E-38700 Santa Cruz de La Palma, Santa Cruz de Tenerife, Spain
36. Osservatorio Astronomico Sirio, I-70013 Castellana Grotte, Italy
37. LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Univ. Paris Diderot, Sorbonne Paris Cité, 5 place Jules Janssen, F-92195 Meudon, France
38. Department of Physics, University of Colorado, Denver, CO 80217-3364, USA
39. Lowell Observatory, Flagstaff, AZ 85751, USA
40. Steward Observatory, University of Arizona, Tucson, AZ 85721, USA
41. Aalto University Metsähovi Radio Observatory, FI-02540 Kylmälä, Finland
42. Instituto de Radio Astronomía Milimétrica, E-18012 Granada, Spain
43. Finnish Center for Astronomy with ESO (FINCA), University of Turku, FI-20014 Turku, Finland, Aalto University Metshovi Radio Observatory, Metshovintie 114, FI-02540 Kylmälä, Finland
44. Owens Valley Radio Observatory, California Institute of Technology, Pasadena, CA 91125, USA
45. Departamento de Astronoma, Universidad de Chile, Camino El Observatorio 1515, Las Condes, Santiago, Chile
46. Departamento de Astronomia, Universidad de Concepcion, Concepcion, Chile
47. Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, China, Kazan Federal University, 18 Kremlyovskaya St, Kazan 420044, Russia
48. Special Astrophysical Observatory of RAS, Nizhnij Arkhyz 369167, Russia
49. Kazan Federal University, 18 Kremlyovskaya St, Kazan 420044, Russia, Special Astrophysical Observatory of RAS, Nizhnij Arkhyz 369167, Russia

ABSTRACT We present a multiwavelength study of the flat-spectrum radio quasar CTA 102 during 2013–2017. We use radio-to-optical data obtained by the Whole Earth Blazar Telescope, 15 GHz data from the Owens Valley Radio Observatory, 91 and 103 GHz data from the Atacama Large Millimeter Array, near-infrared data from the Rapid Eye Monitor telescope, as well as data from the Swift (optical-UV and X-rays) and Fermi (γ-rays) satellites to study flux and spectral variability and the correlation between flux changes at different wavelengths. Unprecedented γ-ray flaring activity was observed during 2016 November–2017 February, with four major outbursts. A peak flux of (2158 ± 63) × 10−8 ph cm−2 s−1, corresponding to a luminosity of (2.2 ± 0.1) × 1050 erg s−1, was reached on 2016 December 28. These four γ-ray outbursts have corresponding events in the near-infrared, optical, and UV bands, with the peaks observed at the same time. A general agreement between X-ray and γ-ray activity is found. The γ-ray flux variations show a general, strong correlation with the optical ones with no time lag between the two bands and a comparable variability amplitude. This γ-ray/optical relationship is in agreement with the geometrical model that has successfully explained the low-energy flux and spectral behaviour, suggesting that the long-term flux variations are mainly due to changes in the Doppler factor produced by variations of the viewing angle of the emitting regions. The difference in behaviour between radio and higher energy emission would be ascribed to different viewing angles of the jet regions producing their emission.

• Sponsoring Organization: USDOE
• OSTI ID: 1576016
• Journal Information: Monthly Notices of the Royal Astronomical Society, Journal Name: Monthly Notices of the Royal Astronomical Society Vol. 490 Journal Issue: 4; ISSN 0035-8711
• Publisher: Oxford University PressCopyright Statement
• Country of Publication: United Kingdom
• Language: English