Multi-frequency VLBA study of the blazar S5 0716+714 during the active state in 2004: I. Inner jet kinematics

Abstract

We observed the blazar \object{0716+714} with the VLBA during its active state in 2003-2004. In this paper we discuss multi-frequency analysis of the inner jet (first 1 mas) kinematics. The unprecedentedly dense time sampling allows us to trace jet components without misidentification and to calculate the component speeds with good accuracy. In the smooth superluminal jet we were able to identify and track three components over time moving outwards with relatively high apparent superluminal speeds (8.5-19.4 $c$), which contradicts the hypothesis of a stationary oscillating jet in this source. Component ejections occur at a relatively high rate (once in two months), and they are accompanied by mm-continuum outbursts. Superluminal jet components move along wiggling trajectories, which is an indication of actual helical motion. Fast proper motion and rapid decay of the components suggest that this source should be observed with the VLBI at a rate of at least once in one or two months in order to trace superluminal jet components without confusion.

arXiv comment4 pages, 3 figures, Astronomy & Astrophysics Letter, language corrections added

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Cited by in corpus (10)

• Kinematics of Parsec-Scale Jets of Gamma-Ray Blazars at 43~GHz within the VLBA-BU-BLAZAR Program
• Multiwavelength Intraday Variability of the BL Lac S5 0716+714
• Long-term variability of extragalactic radio sources in the Planck Early Release Compact Source Catalogue
• Non-radial motion in the TeV blazar S5 0716+714 The pc-scale kinematics of a BL Lac Object
• Powerful high energy emission of the remarkable BL Lac object S5 0716+714
• Probing the innermost regions of AGN jets and their magnetic fields with RadioAstron. III. Blazar S5 0716+71 at microarcsecond resolution
• Multifrequency VLBA study of the blazar S5 0716+714 during the active state in 2004 II. Large-scale jet kinematics and the comparison of the different methods of VLBI data imaging as applied to kinematic studies of AGN
• A geometrical interpretation for the properties of multiband optical variability of the blazar S5 0716+714
• Global alignments of parsec-scale AGN radio jets and their polarization planes
• Long-term multiband optical variability of S5 0716+714 blazar