Details

Autor(en) / Beteiligte

• Escudero Pedrosa, J.
• Agudo, I.
• Tramacere, A.
• Marscher, A. P.
• Jorstad, S.
• Weaver, Z. R.
• Casadio, C.
• Thum, C.
• Myserlis, I.
• Fuentes, A.
• Traianou, E.
• Kim, J.-Y.
• Kramer, J.
• López-Coto, R.
• D’Ammando, F.
• Bernardos, M.
• Bonnoli, G.
• Blinov, D. A.
• Borman, G. A.
• Grishina, T. S.
• Hagen-Thorn, V. A.
• Kopatskaya, E. N.
• Larionova, E. G.
• Larionov, V. M.
• Larionova, L. V.
• Morozova, D. A.
• Savchenko, S. S.
• Troitskiy, I. S.
• Troitskaya, Y. V.
• Vasilyev, A. A.

Titel

Repeating flaring activity of the blazar AO 0235+164

Ist Teil von

• Astronomy and astrophysics (Berlin), 2024-02, Vol.682, p.A100

Ort / Verlag

Heidelberg: EDP Sciences

Erscheinungsjahr

2024

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Context. Blazar AO 0235+164 , located at a redshift of z = 0.94, has undergone several sharp multi-spectral-range flaring episodes over recent decades. In particular, the episodes that peaked in 2008 and 2015, which were subject to extensive multi-wavelength coverage, exhibited an interesting behavior. Aims. We study the actual origin of these two observed flares by constraining the properties of the observed photo-polarimetric variability as well as of the broadband spectral energy distribution and the observed time-evolution behavior of the source. We use ultra-high-resolution total-flux and polarimetric very-long-baseline interferometry (VLBI) imaging. Methods. The analysis of VLBI images allowed us to constrain kinematic and geometrical parameters of the 7 mm jet. We used the discrete correlation function to compute the statistical correlation and the delays between emission at different spectral ranges. The multi-epoch modeling of the spectral energy distributions allowed us to propose specific models of the emission; in particular, with the aim to model the unusual spectral features observed in this source in the X-ray region of the spectrum during strong multi spectral-range flares. Results. We find that these X-ray spectral features can be explained by an emission component originating in a separate particle distribution than the one responsible for the two standard blazar bumps. This is in agreement with the results of our correlation analysis, where we did not find a strong correlation between the X-ray and the remaining spectral ranges. We find that both external Compton-dominated and synchrotron self-Compton-dominated models are able to explain the observed spectral energy distributions. However, the synchrotron self-Compton models are strongly favored by the delays and geometrical parameters inferred from the observations.