The optical behaviour of BL Lacertae at its maximum brightness levels: a blend of geometry and energetics-Reference-Cited by-同舟云学术

The optical behaviour of BL Lacertae at its maximum brightness levels: a blend of geometry and energetics

Published:2023-03-29 Issue:1 Volume:522 Page:102-116
ISSN:0035-8711
Container-title:Monthly Notices of the Royal Astronomical Society
language:en
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Author:

Raiteri C M¹^ORCID,Villata M¹^ORCID,Jorstad S G²³^ORCID,Marscher A P²,Acosta Pulido J A⁴⁵^ORCID,Carosati D⁶⁷,Chen W P⁸,Joner M D⁹^ORCID,Kurtanidze S O¹⁰,Lorey C¹¹,Marchini A¹²^ORCID,Matsumoto K¹³,Mirzaqulov D O¹⁴,Savchenko S S³¹⁵¹⁶^ORCID,Strigachev A¹⁷,Vince O¹⁸,Aceti P¹⁹²⁰^ORCID,Apolonio G⁹,Arena C²¹,Arkharov A¹⁶^ORCID,Bachev R¹⁷,Bader N¹¹,Banfi M¹⁹,Bonnoli G²²,Borman G A²³^ORCID,Bozhilov V²⁴,Brown L F²⁵,Carbonell W²⁵,Carnerero M I¹^ORCID,Damljanovic G¹⁸,Dhiman V²⁶²⁷,Ehgamberdiev S A¹⁴²⁸,Elsaesser D¹¹²⁹,Feige M¹¹,Gabellini D³⁰,Galán D⁵,Galli G³¹,Gaur H²⁶,Gazeas K³²^ORCID,Grishina T S³^ORCID,Gupta A C²⁶³³³⁴^ORCID,Hagen-Thorn V A³^ORCID,Hallum M K²,Hart M²,Hasuda K³⁵,Heidemann K¹¹,Horst B¹¹,Hou W-J⁸,Ibryamov S³⁶^ORCID,Ivanidze R Z¹⁰,Jovanovic M D¹⁸^ORCID,Kimeridze G N¹⁰,Kishore S²⁶³⁷,Klimanov S¹⁶,Kopatskaya E N³^ORCID,Kurtanidze O M¹⁰³⁸³⁹,Kushwaha P²⁶⁴⁰^ORCID,Lane D J⁴¹^ORCID,Larionova E G³^ORCID,Leonini S⁴²,Lin H C⁸,Mannheim K¹¹⁴³,Marino G²¹⁴⁴,Minev M¹⁷²⁴,Modaressi A²⁵,Morozova D A³^ORCID,Mortari F³⁰,Nazarov S V²³,Nikolashvili M G¹⁰,Otero Santos J⁴⁵,Ovcharov E²⁴,Papini R⁴⁴,Pinter V⁴⁵⁴⁶⁴⁷,Privitera C A¹²,Pursimo T⁴⁵⁴⁶,Reinhart D¹¹,Roberts J⁹,Romanov F D⁴⁸⁴⁹^ORCID,Rosenlehner K¹¹,Sakamoto T³⁵,Salvaggio F²¹⁴⁴,Schoch K¹¹,Semkov E¹⁷^ORCID,Seufert J¹¹,Shakhovskoy D²³,Sigua L A¹⁰,Singh C²⁵,Steineke R¹¹,Stojanovic M¹⁸,Tripathi T²⁶³⁷,Troitskaya Y V³^ORCID,Troitskiy I S³^ORCID,Tsai A⁸,Valcheva A²⁴,Vasilyev A A³^ORCID,Vrontaki K³²,Weaver Z R²^ORCID,Wooley J H F⁹,Zaharieva E²⁴,Zhovtan A V²³

Affiliation:

1. INAF, Osservatorio Astrofisico di Torino , via Osservatorio 20, I-10025 Pino Torinese, Italy

2. Institute for Astrophysical Research, Boston University , 725 Commonwealth Avenue, Boston, MA 02215, USA

3. Astronomical Institute, St Petersburg State University , 28 Universitetskiy Prospekt, Peterhof, St Petersburg 198504, Russia

4. Instituto de Astrofísica de Canarias (IAC) , E-38200 La Laguna, Tenerife, Spain

5. Departamento de Astrofisica, Universidad de La Laguna (ULL) , E-38206 Tenerife, Spain

6. EPT Observatories, Tijarafe , La Palma, E-38780, Spain

7. INAF, TNG Fundación Galileo Galilei , La Palma, E-38712, Spain

8. Institute of Astronomy, National Central University , Taoyuan 32001, Taiwan

9. Department of Physics and Astronomy, Brigham Young University , N283 ESC, Provo, UT 84602, USA

10. Abastumani Observatory , Mt. Kanobili, 0301 Abastumani, Georgia

11. Hans-Haffner-Sternwarte, Naturwissenschaftliches Labor für Schüler am FKG, Friedrich-Koenig-Gymnasium , D-97082 Würzburg, Germany

12. Astronomical Observatory, Department of Physical Sciences, Earth and Environment, University of Siena , Siena, I-53100, Italy

13. Astronomical Institute, Osaka Kyoiku University , Kashiwara, 582-8582, Japan

14. Ulugh Beg Astronomical Institute , Astronomy Street 33, Tashkent 100052, Uzbekistan

15. Special Astrophysical Observatory, Russian Academy of Sciences , 369167 Nizhnii Arkhyz, Russia

16. Pulkovo Observatory , St Petersburg 196140, Russia

17. Institute of Astronomy and National Astronomical Observatory, Bulgarian Academy of Sciences , 72 Tsarigradsko Shosse Blvd., 1784 Sofia, Bulgaria

18. Astronomical Observatory , Volgina 7, 11060 Belgrade, Serbia

19. Osservatorio Astronomico Città di Seveso , Seveso, I-20822, Italy

20. Department of Aerospace Science and Technology, Politecnico di Milano , Milano, I-20156, Italy

21. Gruppo Astrofili Catanesi (GAC) , Catania, I-95125, Italy

22. INAF, Osservatorio Astronomico di Brera , via E. Bianchi 46, I-23807 Merate, Italy

23. Crimean Astrophysical Observatory of the Russian Academy of Sciences , P/O Nauchny 298409, Russia

24. Department of Astronomy, Faculty of Physics, Sofia University ‘St. Kliment Ohridski’ , 5 James Bourchier Blvd., BG-1164 Sofia, Bulgaria

25. Department of Physics, Astronomy and Geophysics, Connecticut College , New London, CT 06320, USA

26. Aryabhatta Research Institute of Observational Sciences (ARIES) , Manora Peak, Nainital 263001, India

27. School of Studies in Physics and Astrophysics, Pt. Ravishankar Shukla University , Amanaka G.E. Road, Raipur 492010, India

28. National University of Uzbekistan , Tashkent 100174, Uzbekistan

29. Fakultät Physik, TU Dortmund , D-44227 Dortmund, Germany

30. Hypatia Observatory , Rimini, I-47900, Italy

31. GiaGa Observatory , Pogliano Milanese, I-20005, Italy

32. Section of Astrophysics, Astronomy and Mechanics, Department of Physics, National and Kapodistrian University of Athens , GR-15784 Zografos, Athens, Greece

33. Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences , Shanghai 200030, China

34. Shanghai Frontiers Science Center of Gravitational Wave Detection , 800 Dongchuan Road, Minhang, Shanghai 200240, China

35. Department of Physical Science, Aoyama Gakuin University , 5-10-1 Fuchinobe, Chuo-ku, Sagamihara-shi, Kanagawa 252-5258, Japan

36. Department of Physics and Astronomy, Faculty of Natural Sciences, University of Shumen , 115 Universitetska Str, 9712 Shumen, Bulgaria

37. Department of Physics, DDU Gorakhpur University , Gorakhpur 273009, India

38. Zentrum für Astronomie der Universität Heidelberg , Landessternwarte, Königstuhl 12, D-69117 Heidelberg, Germany

39. Engelhardt Astronomical Observatory, Kazan Federal University , Tatarstan, Russia

40. Department of Physical Sciences, Indian Institute of Science Education and Research (IISER) Mohali , Knowledge City, Sector 81, SAS Nagar, Punjab 140306, India

41. Abbey Ridge Observatory , Canada

42. Montarrenti Observatory , Siena, I-53100, Italy

43. Lehrstuhl für Astronomie, Universität Würzburg , D-97074 Würzburg, Germany

44. Wild Boar Remote Observatory , Florence, I-50026, Italy

45. Nordic Optical Telescope , Apartado 474, E-38700 Santa Cruz de La Palma, Santa Cruz de Tenerife, Spain

46. Department of Physics and Astronomy, Aarhus University , Munkegade 120, DK-8000 Aarhus C, Denmark

47. University of Craiova , Alexandru Ioan Cuza 13, 200585 Craiova, Romania

48. AAVSO Observer , Russia

49. Remote Observer of Burke-Gaffney Observatory and Abbey Ridge Observatory , Canada

Abstract

ABSTRACTIn 2021 BL Lacertae underwent an extraordinary activity phase, which was intensively followed by the Whole Earth Blazar Telescope (WEBT) Collaboration. We present the WEBT optical data in the BVRI bands acquired at 36 observatories around the world. In mid-2021 the source showed its historical maximum, with R = 11.14. The light curves display many episodes of intraday variability, whose amplitude increases with source brightness, in agreement with a geometrical interpretation of the long-term flux behaviour. This is also supported by the long-term spectral variability, with an almost achromatic trend with brightness. In contrast, short-term variations are found to be strongly chromatic and are ascribed to energetic processes in the jet. We also analyse the optical polarimetric behaviour, finding evidence of a strong correlation between the intrinsic fast variations in flux density and those in polarization degree, with a time delay of about 13 h. This suggests a common physical origin. The overall behaviour of the source can be interpreted as the result of two mechanisms: variability on time-scales greater than several days is likely produced by orientation effects, while either shock waves propagating in the jet, or magnetic reconnection, possibly induced by kink instabilities in the jet, can explain variability on shorter time-scales. The latter scenario could also account for the appearance of quasi-periodic oscillations, with periods from a few days to a few hours, during outbursts, when the jet is more closely aligned with our line of sight and the time-scales are shortened by relativistic effects.

Funder

US National Science Foundation

NASA

Bulgarian National Science Fund

Ministry of Education and Science

JSPS

Ministry of Education, Science and Technological Development of the Republic of Serbia

MINECO

MICINN

Spanish State Research Agency

Chinese Academy of Sciences

Chinese Ministry of Science and Technology