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The outburst of the blazar S4 0954+658 in 2011 March-April
journal contribution
posted on 2023-05-18, 07:23 authored by Morozova, DA, Larionov, VM, Troitsky, IS, Jorstad, SG, Marscher, AP, Gomez, JL, Blinov, DA, Efimova, NV, Hagen-Thorn, VA, Hagen-Thorn, EI, Joshi, M, Konstantinova, TS, Kopatskaya, EN, Larionova, LV, Larionova, EG, Lahteenmaki, A, Tammi, J, Rastorgueva-Foi, E, McHardy, I, Tornikoski, M, Agudo, I, Casadio, C, Molina, SN, Volvach, AE, Volvach, LNWe present the results of optical (R-band) photometric and polarimetric monitoring and Very Long Baseline Array imaging of the blazar S4 0954+658, along with Fermi γ-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 2011 January, 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 hr. During the rise of the flux, the position angle of the optical polarization rotated smoothly over more than 300°. At the same time, within 1σ uncertainty, a new superluminal knot appeared with an apparent speed of 19.0 ± 0.3c. We have very strong evidence that this knot is associated 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 2008 August to 2012 April. We find some evidence of connections between at least two additional superluminal ejecta and near-simultaneous optical flares.
History
Publication title
The Astrophysical JournalVolume
148Article number
42Number
42Pagination
1-9ISSN
0004-637XDepartment/School
School of Natural SciencesPublisher
Univ Chicago PressPlace of publication
1427 E 60Th St, Chicago, USA, Il, 60637-2954Rights statement
Copyright 2014 The American Astronomical SocietyRepository Status
- Restricted