Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
The complex variability of blazars : Time-scales and periodicity analysis in S4 0954+65. / WEBT Collaboration.
в: Monthly Notices of the Royal Astronomical Society, Том 504, № 4, 01.07.2021, стр. 5629-5646.Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
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TY - JOUR
T1 - The complex variability of blazars
T2 - Time-scales and periodicity analysis in S4 0954+65
AU - WEBT Collaboration
AU - Raiteri, C. M.
AU - Villata, M.
AU - Larionov, V. M.
AU - Jorstad, S. G.
AU - Marscher, A. P.
AU - Weaver, Z. R.
AU - Acosta-Pulido, J. A.
AU - Agudo, I.
AU - Andreeva, T.
AU - Arkharov, A.
AU - Bachev, R.
AU - Benítez, E.
AU - Berton, M.
AU - Björklund, I.
AU - Borman, G. A.
AU - Bozhilov, V.
AU - Carnerero, M. I.
AU - Carosati, D.
AU - Casadio, C.
AU - Chen, W. P.
AU - Damljanovic, G.
AU - D'Ammando, F.
AU - Escudero, J.
AU - Fuentes, A.
AU - Giroletti, M.
AU - Grishina, T. S.
AU - Gupta, A. C.
AU - Hagen-Thorn, V. A.
AU - Hart, M.
AU - Hiriart, D.
AU - Hou, W. J.
AU - Ivanov, D.
AU - Kim, J. Y.
AU - Kimeridze, G. N.
AU - Konstantopoulou, C.
AU - Kopatskaya, E. N.
AU - Kurtanidze, O. M.
AU - Kurtanidze, S. O.
AU - Lähteenmäki, A.
AU - Larionova, E. G.
AU - Larionova, L. V.
AU - Marchili, N.
AU - Markovic, G.
AU - Minev, M.
AU - Morozova, D. A.
AU - Myserlis, I.
AU - Nikiforova, A. A.
AU - Savchenko, S. S.
AU - Troitskaya, Y. V.
AU - Vasilyev, A. A.
N1 - Publisher Copyright: © 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.
PY - 2021/7/1
Y1 - 2021/7/1
N2 - Among active galactic nuclei, blazars show extreme variability properties. We here investigate the case of the BL Lac object S4 0954+65 with data acquired in 2019-2020 by the Transiting Exoplanet Survey Satellite (TESS) and by the Whole Earth Blazar Telescope (WEBT) Collaboration. The 2-min cadence optical light curves provided by TESS during three observing sectors of nearly 1 month each allow us to study the fast variability in great detail. We identify several characteristic short-term time-scales, ranging from a few hours to a few days. However, these are not persistent, as they differ in the various TESS sectors. The long-term photometric and polarimetric optical and radio monitoring undertaken by the WEBT brings significant additional information, revealing that (i) in the optical, long-term flux changes are almost achromatic, while the short-term ones are strongly chromatic; (ii) the radio flux variations at 37 GHz follow those in the optical with a delay of about 3 weeks; (iii) the range of variation of the polarization degree and angle is much larger in the optical than in the radio band, but the mean polarization angles are similar; (iv) the optical long-term variability is characterized by a quasi-periodicity of about 1 month. We explain the source behaviour in terms of a rotating inhomogeneous helical jet, whose pitch angle can change in time.
AB - Among active galactic nuclei, blazars show extreme variability properties. We here investigate the case of the BL Lac object S4 0954+65 with data acquired in 2019-2020 by the Transiting Exoplanet Survey Satellite (TESS) and by the Whole Earth Blazar Telescope (WEBT) Collaboration. The 2-min cadence optical light curves provided by TESS during three observing sectors of nearly 1 month each allow us to study the fast variability in great detail. We identify several characteristic short-term time-scales, ranging from a few hours to a few days. However, these are not persistent, as they differ in the various TESS sectors. The long-term photometric and polarimetric optical and radio monitoring undertaken by the WEBT brings significant additional information, revealing that (i) in the optical, long-term flux changes are almost achromatic, while the short-term ones are strongly chromatic; (ii) the radio flux variations at 37 GHz follow those in the optical with a delay of about 3 weeks; (iii) the range of variation of the polarization degree and angle is much larger in the optical than in the radio band, but the mean polarization angles are similar; (iv) the optical long-term variability is characterized by a quasi-periodicity of about 1 month. We explain the source behaviour in terms of a rotating inhomogeneous helical jet, whose pitch angle can change in time.
KW - BL Lacertae objects: general
KW - BL Lacertae objects: individual: S4 0954+65
KW - Galaxies: active
KW - Galaxies: jets
UR - http://www.scopus.com/inward/record.url?scp=85108587265&partnerID=8YFLogxK
U2 - 10.1093/mnras/stab1268
DO - 10.1093/mnras/stab1268
M3 - Article
AN - SCOPUS:85108587265
VL - 504
SP - 5629
EP - 5646
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 4
ER -
ID: 84328154