The correlated optical and radio variability of BL Lacertae. WEBT data analysis 1994-2005

Autor: M. Villata, C. M. Raiteri, V. M. Larionov, M. G. Nikolashvili, M. F. Aller, U. Bach, D. Carosati, F. Hroch, M. A. Ibrahimov, S. G. Jorstad, Y. Y. Kovalev, A. Lähteenmäki, K. Nilsson, H. Teräsranta, G. Tosti, H. D. Aller, A. A. Arkharov, A. Berdyugin, P. Boltwood, C. S. Buemi, R. Casas, P. Charlot, J. M. Coloma, A. Di Paola, G. Di Rico, G. N. Kimeridze, T. S. Konstantinova, E. N. Kopatskaya, Yu. A. Kovalev, O. M. Kurtanidze, L. Lanteri, E. G. Larionova, L. V. Larionova, J.-F. Le Campion, P. Leto, E. Lindfors, A. P. Marscher, K. Marshall, J. P. McFarland, I. M. McHardy, H. R. Miller, G. Nucciarelli, M. P. Osterman, M. Pasanen, T. Pursimo, J. A. Ros, A. C. Sadun, L. A. Sigua, L. Sixtova, L. O. Takalo, M. Tornikoski, C. Trigilio, G. Umana, G. Z. Xie, X. Zhang, S. B. Zhou
Přispěvatelé: INAF - Osservatorio Astrofisico di Torino (OATo), Istituto Nazionale di Astrofisica (INAF), Instituto de Neurociencias de Alicante, Universidad Miguel Hernández [Elche] (UMH), Dipartimento di Fisica e Geologia [Perugia], Università degli Studi di Perugia = University of Perugia (UNIPG), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Departamento de Bioquímica y Biología Molecular, Universitat de València (UV), Abteilung Klinische Sozialmedizin, Berufs- und Umweltdermatologie, Universität Heidelberg [Heidelberg] = Heidelberg University, Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Perugia (UNIPG), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Facultad de Farmacia, Universidad de Valencia, Valencia, Spain, Universität Heidelberg [Heidelberg], Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)
Rok vydání: 2009
Předmět:
Cosmology and Nongalactic Astrophysics (astro-ph.CO)
[PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]
galaxies: active
[SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]
FOS: Physical sciences
Astrophysics
01 natural sciences
law.invention
Telescope
law
0103 physical sciences
galaxies: BL Lacertae objects: individual: BL Lacertae
Blazar
010303 astronomy & astrophysics
ComputingMilieux_MISCELLANEOUS
Physics
galaxies: BL Lacertae objects: individual: BL Lacertae
010308 nuclear & particles physics
galaxies: BL Lacertae objects: general
galaxies: jets
galaxies: quasars: general
Radio flux
Astronomy and Astrophysics
Light curve
Space and Planetary Science
Correlation analysis
Astrophysics - Cosmology and Nongalactic Astrophysics
Zdroj: Astronomy and Astrophysics-A&A
Astronomy and Astrophysics-A&A, 2009, 501, pp.455-460. ⟨10.1051/0004-6361/200912065⟩
Astronomy and Astrophysics-A&A, EDP Sciences, 2009, 501, pp.455-460. ⟨10.1051/0004-6361/200912065⟩
ISSN: 0004-6361
DOI: 10.48550/arxiv.0905.1616
Popis: Since 1997, BL Lacertae has undergone a phase of high optical activity, with the occurrence of several prominent outbursts. Starting from 1999, the Whole Earth Blazar Telescope (WEBT) consortium has organized various multifrequency campaigns on this blazar, collecting tens of thousands of data points. One of the main issues in the study of this huge dataset has been the search for correlations between the optical and radio flux variations, and for possible periodicities in the light curves. The analysis of the data assembled during the first four campaigns (comprising also archival data to cover the period 1968-2003) revealed a fair optical-radio correlation in 1994-2003, with a delay of the hard radio events of ~100 days. Moreover, various statistical methods suggested the existence of a radio periodicity of ~8 years. In 2004 the WEBT started a new campaign to extend the dataset to the most recent observing seasons, in order to possibly confirm and better understand the previous results. In this campaign we have collected and assembled about 11000 new optical observations from twenty telescopes, plus near-IR and radio data at various frequencies. Here, we perform a correlation analysis on the long-term R-band and radio light curves. In general, we confirm the ~100-day delay of the hard radio events with respect to the optical ones, even if longer (~200-300 days) time lags are also found in particular periods. The radio quasi-periodicity is confirmed too, but the "period" seems to progressively lengthen from 7.4 to 9.3 years in the last three cycles. The optical and radio behaviour in the last forty years suggests a scenario where geometric effects play a major role. In particular, the alternation of enhanced and suppressed optical activity (accompanied by hard and soft radio events, respectively) can
Comment: 6 pages, 4 figures
Databáze: OpenAIRE
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