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The correlated optical and radio variability of BL Lacertae WEBT data analysis 1994-2005. / Villata, M.; Raiteri, C. M.; Larionov, V. M.; Nikolashvili, M. G.; Aller, M. F.; Bach, U.; Carosati, D.; Hroch, F.; Ibrahimov, M. A.; Jorstad, S. G. ; Kovalev, Y. Y.; Lahteenmaki, A.; Nilsson, K.; Terasranta, H.; Tosti, G.; Aller, H. D.; Arkharov, A. A.; Berdyugin, A.; Boltwood, P.; Buemi, C. S.; Casas, R.; Charlot, P.; Coloma, J. M.; Di Paola, A.; Di Rico, G.; Kimeridze, G. N.; Konstantinova, T. S.; Kopatskaya, E. N.; Kovalev, Yu. A.; Kurtanidze, O. M.; Lanteri, L.; Larionova, E. G.; Larionova, L. V.; Le Campion, J. -F.; Leto, P.; Lindfors, E.; Marscher, A. P.; Marshall, K.; McFarland, J. P.; McHardy, I. M.; Miller, H. R.; Nucciarelli, G.; Osterman, M. P.; Pasanen, M.; Pursimo, T.; Ros, J. A.; Sadun, A. C.; Sigua, L. A.; Sixtova, L.; Takalo, L. O.; Tornikoski, M.; Trigilio, C.; Umana, G.; Xie, G. Z.; Zhang, X.; Zhou, S. B.

In: Astronomy and Astrophysics, Vol. 501, No. 2, 07.2009, p. 455-460.

Research output: Contribution to journalArticlepeer-review

Harvard

Villata, M, Raiteri, CM, Larionov, VM, Nikolashvili, MG, Aller, MF, Bach, U, Carosati, D, Hroch, F, Ibrahimov, MA, Jorstad, SG, Kovalev, YY, Lahteenmaki, A, Nilsson, K, Terasranta, H, Tosti, G, Aller, HD, Arkharov, AA, Berdyugin, A, Boltwood, P, Buemi, CS, Casas, R, Charlot, P, Coloma, JM, Di Paola, A, Di Rico, G, Kimeridze, GN, Konstantinova, TS, Kopatskaya, EN, Kovalev, YA, Kurtanidze, OM, Lanteri, L, Larionova, EG, Larionova, LV, Le Campion, J-F, Leto, P, Lindfors, E, Marscher, AP, Marshall, K, McFarland, JP, McHardy, IM, Miller, HR, Nucciarelli, G, Osterman, MP, Pasanen, M, Pursimo, T, Ros, JA, Sadun, AC, Sigua, LA, Sixtova, L, Takalo, LO, Tornikoski, M, Trigilio, C, Umana, G, Xie, GZ, Zhang, X & Zhou, SB 2009, 'The correlated optical and radio variability of BL Lacertae WEBT data analysis 1994-2005', Astronomy and Astrophysics, vol. 501, no. 2, pp. 455-460. https://doi.org/10.1051/0004-6361/200912065

APA

Villata, M., Raiteri, C. M., Larionov, V. M., Nikolashvili, M. G., Aller, M. F., Bach, U., Carosati, D., Hroch, F., Ibrahimov, M. A., Jorstad, S. G., Kovalev, Y. Y., Lahteenmaki, A., Nilsson, K., Terasranta, H., Tosti, G., Aller, H. D., Arkharov, A. A., Berdyugin, A., Boltwood, P., ... Zhou, S. B. (2009). The correlated optical and radio variability of BL Lacertae WEBT data analysis 1994-2005. Astronomy and Astrophysics, 501(2), 455-460. https://doi.org/10.1051/0004-6361/200912065

Vancouver

Villata M, Raiteri CM, Larionov VM, Nikolashvili MG, Aller MF, Bach U et al. The correlated optical and radio variability of BL Lacertae WEBT data analysis 1994-2005. Astronomy and Astrophysics. 2009 Jul;501(2):455-460. https://doi.org/10.1051/0004-6361/200912065

Author

Villata, M. ; Raiteri, C. M. ; Larionov, V. M. ; Nikolashvili, M. G. ; Aller, M. F. ; Bach, U. ; Carosati, D. ; Hroch, F. ; Ibrahimov, M. A. ; Jorstad, S. G. ; Kovalev, Y. Y. ; Lahteenmaki, A. ; Nilsson, K. ; Terasranta, H. ; Tosti, G. ; Aller, H. D. ; Arkharov, A. A. ; Berdyugin, A. ; Boltwood, P. ; Buemi, C. S. ; Casas, R. ; Charlot, P. ; Coloma, J. M. ; Di Paola, A. ; Di Rico, G. ; Kimeridze, G. N. ; Konstantinova, T. S. ; Kopatskaya, E. N. ; Kovalev, Yu. A. ; Kurtanidze, O. M. ; Lanteri, L. ; Larionova, E. G. ; Larionova, L. V. ; Le Campion, J. -F. ; Leto, P. ; Lindfors, E. ; Marscher, A. P. ; Marshall, K. ; McFarland, J. P. ; McHardy, I. M. ; Miller, H. R. ; Nucciarelli, G. ; Osterman, M. P. ; Pasanen, M. ; Pursimo, T. ; Ros, J. A. ; Sadun, A. C. ; Sigua, L. A. ; Sixtova, L. ; Takalo, L. O. ; Tornikoski, M. ; Trigilio, C. ; Umana, G. ; Xie, G. Z. ; Zhang, X. ; Zhou, S. B. / The correlated optical and radio variability of BL Lacertae WEBT data analysis 1994-2005. In: Astronomy and Astrophysics. 2009 ; Vol. 501, No. 2. pp. 455-460.

BibTeX

@article{2c91ebcaaa3b43efa18ded8da906a7dc,
title = "The correlated optical and radio variability of BL Lacertae WEBT data analysis 1994-2005",
abstract = "Context. 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 similar to 100 days. Moreover, various statistical methods suggested the existence of a radio periodicity of similar to 8 years.Aims. 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.Methods. In this campaign we have collected and assembled about 11 000 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.Results. In general, we confirm the similar to 100-day delay of the hard radio events with respect to the optical ones, even if longer (similar to 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 be explained in terms of an emitting plasma flowing along a rotating helical path in a curved jet.",
keywords = "galaxies: active, galaxies: BL Lacertae objects: general, galaxies: BL Lacertae objects: individual: BL Lacertae, galaxies: jets, galaxies: quasars: general, LIGHT CURVES, SPECTRAL VARIABILITY, HELICAL JETS, BLAZARS, CAMPAIGNS, OBJECTS, GHZ",
author = "M. Villata and Raiteri, {C. M.} and Larionov, {V. M.} and Nikolashvili, {M. G.} and Aller, {M. F.} and U. Bach and D. Carosati and F. Hroch and Ibrahimov, {M. A.} and Jorstad, {S. G.} and Kovalev, {Y. Y.} and A. Lahteenmaki and K. Nilsson and H. Terasranta and G. Tosti and Aller, {H. D.} and Arkharov, {A. A.} and A. Berdyugin and P. Boltwood and Buemi, {C. S.} and R. Casas and P. Charlot and Coloma, {J. M.} and {Di Paola}, A. and {Di Rico}, G. and Kimeridze, {G. N.} and Konstantinova, {T. S.} and Kopatskaya, {E. N.} and Kovalev, {Yu. A.} and Kurtanidze, {O. M.} and L. Lanteri and Larionova, {E. G.} and Larionova, {L. V.} and {Le Campion}, {J. -F.} and P. Leto and E. Lindfors and Marscher, {A. P.} and K. Marshall and McFarland, {J. P.} and McHardy, {I. M.} and Miller, {H. R.} and G. Nucciarelli and Osterman, {M. P.} and M. Pasanen and T. Pursimo and Ros, {J. A.} and Sadun, {A. C.} and Sigua, {L. A.} and L. Sixtova and Takalo, {L. O.} and M. Tornikoski and C. Trigilio and G. Umana and Xie, {G. Z.} and X. Zhang and Zhou, {S. B.}",
year = "2009",
month = jul,
doi = "10.1051/0004-6361/200912065",
language = "Английский",
volume = "501",
pages = "455--460",
journal = "ASTRONOMY & ASTROPHYSICS",
issn = "0004-6361",
publisher = "EDP Sciences",
number = "2",

}

RIS

TY - JOUR

T1 - The correlated optical and radio variability of BL Lacertae WEBT data analysis 1994-2005

AU - Villata, M.

AU - Raiteri, C. M.

AU - Larionov, V. M.

AU - Nikolashvili, M. G.

AU - Aller, M. F.

AU - Bach, U.

AU - Carosati, D.

AU - Hroch, F.

AU - Ibrahimov, M. A.

AU - Jorstad, S. G.

AU - Kovalev, Y. Y.

AU - Lahteenmaki, A.

AU - Nilsson, K.

AU - Terasranta, H.

AU - Tosti, G.

AU - Aller, H. D.

AU - Arkharov, A. A.

AU - Berdyugin, A.

AU - Boltwood, P.

AU - Buemi, C. S.

AU - Casas, R.

AU - Charlot, P.

AU - Coloma, J. M.

AU - Di Paola, A.

AU - Di Rico, G.

AU - Kimeridze, G. N.

AU - Konstantinova, T. S.

AU - Kopatskaya, E. N.

AU - Kovalev, Yu. A.

AU - Kurtanidze, O. M.

AU - Lanteri, L.

AU - Larionova, E. G.

AU - Larionova, L. V.

AU - Le Campion, J. -F.

AU - Leto, P.

AU - Lindfors, E.

AU - Marscher, A. P.

AU - Marshall, K.

AU - McFarland, J. P.

AU - McHardy, I. M.

AU - Miller, H. R.

AU - Nucciarelli, G.

AU - Osterman, M. P.

AU - Pasanen, M.

AU - Pursimo, T.

AU - Ros, J. A.

AU - Sadun, A. C.

AU - Sigua, L. A.

AU - Sixtova, L.

AU - Takalo, L. O.

AU - Tornikoski, M.

AU - Trigilio, C.

AU - Umana, G.

AU - Xie, G. Z.

AU - Zhang, X.

AU - Zhou, S. B.

PY - 2009/7

Y1 - 2009/7

N2 - Context. 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 similar to 100 days. Moreover, various statistical methods suggested the existence of a radio periodicity of similar to 8 years.Aims. 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.Methods. In this campaign we have collected and assembled about 11 000 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.Results. In general, we confirm the similar to 100-day delay of the hard radio events with respect to the optical ones, even if longer (similar to 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 be explained in terms of an emitting plasma flowing along a rotating helical path in a curved jet.

AB - Context. 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 similar to 100 days. Moreover, various statistical methods suggested the existence of a radio periodicity of similar to 8 years.Aims. 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.Methods. In this campaign we have collected and assembled about 11 000 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.Results. In general, we confirm the similar to 100-day delay of the hard radio events with respect to the optical ones, even if longer (similar to 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 be explained in terms of an emitting plasma flowing along a rotating helical path in a curved jet.

KW - galaxies: active

KW - galaxies: BL Lacertae objects: general

KW - galaxies: BL Lacertae objects: individual: BL Lacertae

KW - galaxies: jets

KW - galaxies: quasars: general

KW - LIGHT CURVES

KW - SPECTRAL VARIABILITY

KW - HELICAL JETS

KW - BLAZARS

KW - CAMPAIGNS

KW - OBJECTS

KW - GHZ

U2 - 10.1051/0004-6361/200912065

DO - 10.1051/0004-6361/200912065

M3 - статья

VL - 501

SP - 455

EP - 460

JO - ASTRONOMY & ASTROPHYSICS

JF - ASTRONOMY & ASTROPHYSICS

SN - 0004-6361

IS - 2

ER -

ID: 17058156