Multi-wavelength picture of the misaligned BL Lac object 3C 371


Por: Otero-Santos, J, Raiteri, CM, Tramacere, A, Pedrosa, JE, Acosta-Pulido, JA, Carnerero, MI, Villata, M, Agudo, I, Rahimov, IA, Andreeva, TS, Ivanov, DV, Marchili, N, Righini, S, Giroletti, M, Gurwell, MA, Savchenko, SS, Carosati, D, Chen, WP, Kurtanidze, SO, Joner, MD, Semkov, E, Pursimo, T, Benítez, E, Damljanovic, G, Andreuzzi, G, Apolonio, G, Borman, GA, Bozhilov, V, Galindo-Guil, FJ, Grishina, TS, Hagen-Thorn, VA, Hiriart, D, Hsiao, HY, Ibryamov, S, Ivanidze, RZ, Kimeridze, GN, Kopatskaya, EN, Kurtanidze, OM, Larionov, VM, Larionova, EG, Larionova, LV, Minev, M, Morozova, DA, Nikolashvili, MG, Ovcharov, E, Sigua, LA, Stojanovic, M, Troitskiy, IS, Troitskaya, YV, Tsai, A, Valcheva, A, Vasilyev, AA, Vince, O, Zaharieva, E, Zhovtan, AV

Publicada: 17 ene 2025
Resumen:
Context. The BL Lac object 3C 371 is one of the targets regularly monitored by the Whole-Earth Blazar Telescope (WEBT), a collaboration of observers studying blazar variability on both short and long timescales. Aims. We aim to evaluate the long-term multi-wavelength (MWL) behaviour of 3C 371, comparing it with results derived from its optical emission in our previous study. For this, we make use of the multi-band campaigns organised by the WEBT collaboration in optical and radio between January 2018 and December 2020, and of public data from Swift and Fermi satellites and the MOJAVE Very Large Interferometry programme. Methods. We evaluated the variability shown by the source in each band by quantifying the amplitude variability parameter, and also looked for a possible inter-band correlation using the z-discrete correlation function. We also present a deep analysis of the optical-UV, X-ray, and gamma-ray spectral variability. With the MOJAVE data, we performed a kinematics analysis, looking for components propagating along the jet and calculating its kinematics parameters. We then used this set of parameters to interpret the source MWL behaviour, modelling its broadband spectral energy distribution (SED) with theoretical blazar emission scenarios. Results. The MWL variability of the source in the UV, X-ray, and gamma-ray bands is comparable to that in optical, especially considering the lower coverage of the first two wavebands. On the other hand, the radio bands show variability of much lower magnitude. Moreover, this MWL emission shows a high degree of correlation, which is compatible with zero lag, again with the exception of the radio emission. The radio VLBI images reveal super-luminal motion of one of the identified components, which we used to set constraints on the jet kinematics and parameters, and to estimate a viewing angle of theta = (9.6 +/- 1.6)degrees, a Doppler factor of delta = 6.0 +/- 1.1, and a Lorentz factor of Gamma = 6.0 +/- 1.8. The polarised radio emission was found to be anti-correlated with the total flux, and to follow the same behaviour as the polarised optical radiation. The optical-UV spectral behaviour shows a mild harder-when-brighter trend on long timescales, and other trends such as redder-when-brighter on shorter timescales. We successfully modelled the broadband emission with a leptonic scenario, where we compared the low and high emission states during the period of complete MWL coverage. The difference between these two states can be ascribed mainly to a hardening of the distribution of particles. The derived features of the source confirm that 3C 371 is a BL Lac whose jet is not well aligned with the line of sight.

Filiaciones:
Otero-Santos, J:
 Inst Astrofis Andalucia CSIC, Glorieta Astron S-N, Granada 18008, Spain

 Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy

Raiteri, CM:
 INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy

Tramacere, A:
 Univ Geneva, Dept Astron, Chemin Pegasi 51, CH-1290 Versoix, Switzerland

Pedrosa, JE:
 Inst Astrofis Andalucia CSIC, Glorieta Astron S-N, Granada 18008, Spain

Acosta-Pulido, JA:
 Inst Astrofis Canarias IAC, E-38200 San Cristobal la Laguna, Tenerife, Spain

 Univ La Laguna ULL, Dept Astrofis, E-38206 San Cristobal la Laguna, Tenerife, Spain

Carnerero, MI:
 INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy

Villata, M:
 INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy

Agudo, I:
 Inst Astrofis Andalucia CSIC, Glorieta Astron S-N, Granada 18008, Spain

Rahimov, IA:
 Russian Acad Sci, Inst Appl Astron, St Petersburg, Russia

Andreeva, TS:
 Russian Acad Sci, Inst Appl Astron, St Petersburg, Russia

Ivanov, DV:
 Russian Acad Sci, Inst Appl Astron, St Petersburg, Russia

Marchili, N:
 INAF Ist Radioastron, Via Gobetti 101, I-40129 Bologna, Italy

Righini, S:
 INAF Ist Radioastron, Via Gobetti 101, I-40129 Bologna, Italy

Giroletti, M:
 INAF Ist Radioastron, Via Gobetti 101, I-40129 Bologna, Italy

Gurwell, MA:
 Ctr Astrophys Harvard & Smithsonian, 60 Garden St, Cambridge, MA 02138 USA

Savchenko, SS:
 St Petersburg State Univ, 7-9 Univ Skaya Nab, St Petersburg 199034, Russia

 Russian Acad Sci, Special Astrophys Observ, Nizhnii Arkhyz 369167, Russia

 Pulkovo Observ, St Petersburg 196140, Russia

Carosati, D:
 EPT Observ, Tijarafe, La Plama, Spain

 TNG Fdn Galileo Galilei, INAF, La Palma, Spain

Chen, WP:
 Natl Cent Univ, Inst Astron, Taoyuan 32001, Taiwan

Kurtanidze, SO:
 Abastumani Observ, GE-0301 Mt Kanobili, Abastumani, Georgia

Joner, MD:
 Brigham Young Univ, Dept Phys & Astron, N283 ESC, Provo, UT 84602 USA

Semkov, E:
 Bulgarian Acad Sci, Inst Astron, 72 Tsarigradsko Shosse Blvd, Sofia 1784, Bulgaria

 Bulgarian Acad Sci, Natl Astron Observ, 72 Tsarigradsko Shosse Blvd, Sofia 1784, Bulgaria

Pursimo, T:
 Nord Opt Telescope, Apartado 474, E-38700 Santa Cruz De La Palma, Santa Cruz De T, Spain

 Aarhus Univ, Dept Phys & Astron, Munkegade 120, DK-8000 Aarhus C, Denmark

Benítez, E:
 Univ Nacl Autonoma Mexico, Inst Astron, AP 70-264, Cdmx 04510, Mexico

Damljanovic, G:
 Astron Observ, Volgina 7, Belgrade 11060, Serbia

Andreuzzi, G:
 TNG Fdn Galileo Galilei, INAF, La Palma, Spain

Apolonio, G:
 Brigham Young Univ, Dept Phys & Astron, N283 ESC, Provo, UT 84602 USA

Borman, GA:
 Crimean Astrophys Observ RAS, Crimea 298409, Russia

Bozhilov, V:
 Sofia Univ St Kliment Ohridski, Fac Phys, Dept Astron, 5 James Bourchier Blvd, BG-1164 Sofia, Bulgaria

Galindo-Guil, FJ:
 Ctr Estudios Fis Cosmos Aragon CEFCA, Plaza San Juan 1, Teruel 44001, Spain

Grishina, TS:
 St Petersburg State Univ, 7-9 Univ Skaya Nab, St Petersburg 199034, Russia

Hagen-Thorn, VA:
 St Petersburg State Univ, 7-9 Univ Skaya Nab, St Petersburg 199034, Russia

Hiriart, D:
 Univ Nacl Autonoma Mexico, Inst Astron, AP 106, Ensenada 22800, Baja California, Mexico

Hsiao, HY:
 Natl Cent Univ, Inst Astron, Taoyuan 32001, Taiwan

Ibryamov, S:
 Univ Shumen, Fac Nat Sci, Dept Phys, 115 Univ Ska Str, Shumen 9712, Bulgaria

Ivanidze, RZ:
 Abastumani Observ, GE-0301 Mt Kanobili, Abastumani, Georgia

Kimeridze, GN:
 Abastumani Observ, GE-0301 Mt Kanobili, Abastumani, Georgia

Kopatskaya, EN:
 St Petersburg State Univ, 7-9 Univ Skaya Nab, St Petersburg 199034, Russia

Kurtanidze, OM:
 Abastumani Observ, GE-0301 Mt Kanobili, Abastumani, Georgia

 Kazan Fed Univ, Engelhardt Astron Observ, Tatarstan, Russia

Larionov, VM:
 St Petersburg State Univ, 7-9 Univ Skaya Nab, St Petersburg 199034, Russia

Larionova, EG:
 St Petersburg State Univ, 7-9 Univ Skaya Nab, St Petersburg 199034, Russia

Larionova, LV:
 St Petersburg State Univ, 7-9 Univ Skaya Nab, St Petersburg 199034, Russia

Minev, M:
 Bulgarian Acad Sci, Inst Astron, 72 Tsarigradsko Shosse Blvd, Sofia 1784, Bulgaria

 Bulgarian Acad Sci, Natl Astron Observ, 72 Tsarigradsko Shosse Blvd, Sofia 1784, Bulgaria

 Sofia Univ St Kliment Ohridski, Fac Phys, Dept Astron, 5 James Bourchier Blvd, BG-1164 Sofia, Bulgaria

Morozova, DA:
 St Petersburg State Univ, 7-9 Univ Skaya Nab, St Petersburg 199034, Russia

Nikolashvili, MG:
 Abastumani Observ, GE-0301 Mt Kanobili, Abastumani, Georgia

Ovcharov, E:
 Sofia Univ St Kliment Ohridski, Fac Phys, Dept Astron, 5 James Bourchier Blvd, BG-1164 Sofia, Bulgaria

Sigua, LA:
 Abastumani Observ, GE-0301 Mt Kanobili, Abastumani, Georgia

Stojanovic, M:
 Astron Observ, Volgina 7, Belgrade 11060, Serbia

Troitskiy, IS:
 St Petersburg State Univ, 7-9 Univ Skaya Nab, St Petersburg 199034, Russia

Troitskaya, YV:
 St Petersburg State Univ, 7-9 Univ Skaya Nab, St Petersburg 199034, Russia

Tsai, A:
 Natl Cent Univ, Inst Astron, Taoyuan 32001, Taiwan

 Natl Sun Yat Sen Univ, 70 Lien Hai Rd, Kaohsiung 804201, Taiwan

 ViewMove Technol Inc, Taoyuan 32001, Taiwan

Valcheva, A:
 Sofia Univ St Kliment Ohridski, Fac Phys, Dept Astron, 5 James Bourchier Blvd, BG-1164 Sofia, Bulgaria

Vasilyev, AA:
 St Petersburg State Univ, 7-9 Univ Skaya Nab, St Petersburg 199034, Russia

Vince, O:
 Astron Observ, Volgina 7, Belgrade 11060, Serbia

Zaharieva, E:
 Sofia Univ St Kliment Ohridski, Fac Phys, Dept Astron, 5 James Bourchier Blvd, BG-1164 Sofia, Bulgaria

Zhovtan, AV:
 Crimean Astrophys Observ RAS, Crimea 298409, Russia
ISSN: 00046361
Editorial
EDP SCIENCES S A, 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE, Francia
Tipo de documento: Article
Volumen: 693 Número:
Páginas:
WOS Id: 001398599400026
imagen Green Submitted, All Open Access; Green Open Access