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arXiv · 1406.2286

The Outburst of the Blazar S40954+658 in March-April 2011

D. A. Morozova·V. M. Larionov·I. S. Troitsky·S. G. Jorstad·A. P. Marscher·J. L. Gómez·D. A. Blinov·N. V. Efimova·V. A. Hagen-Thorn·E. I. Hagen-Thorn·M. Joshi·T. S. Konstantinova·E. N. Kopatskaya·L. V. Larionova·E. G. Larionova·A. Lähteenmäki·J. Tammi·E. Rastorgueva-Foi·I. McHardy·M. Tornikoski·I. Agudo·C. Casadio·S. N. Molina·A. E. Volvach·L. N. Volvach
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Abstract

We present the results of optical (R band) photometric and polarimetric monitoring and Very Long Baseline Array (VLBA) imaging of the blazar S4 0954+658, along with Fermi and gamma;-ray data during a multi-waveband outburst in 2011 March-April. After a faint state with a brightness level R ~17.6 mag registered in the first half of January 2011, the optical brightness of the source started to rise and reached ~14.8 mag during the middle of March, showing flare-like behavior. The most spectacular case of intranight variability was observed during the night of 2011 March 9, when the blazar brightened by ~0.7 mag within ~7 hours. During the rise of the flux the position angle of optical polarization rotated smoothly over more than 300$°$. At the same time, within 1$σ$ uncertainty a new superluminal knot appeared with an apparent speed of 19.0$\pm$0.3 c. We have very strong evidence for association of this knot with the multi-waveband outburst in 2011 March-April. We also analyze the multi-frequency behavior of S4 0954+658 during a number of minor outbursts from August 2008 to April 2012. We find some evidence of connections between at least two more superluminal ejecta and near-simultaneous optical flares.

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D. A. Morozova, V. M. Larionov, I. S. Troitsky, S. G. Jorstad, A. P. Marscher, J. L. Gómez, D. A. Blinov, N. V. Efimova, V. A. Hagen-Thorn, E. I. Hagen-Thorn, M. Joshi, T. S. Konstantinova, E. N. Kopatskaya, L. V. Larionova, E. G. Larionova, A. Lähteenmäki, J. Tammi, E. Rastorgueva-Foi, I. McHardy, M. Tornikoski, I. Agudo, C. Casadio, S. N. Molina, A. E. Volvach, L. N. Volvach. 2014-06-09. The Outburst of the Blazar S40954+658 in March-April 2011. https://doi.org/10.1088/0004-6256%2F148%2F3%2F42

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