Abstract
Using millimeter very long baseline interferometry (VLBI) observations of the BL Lac object S5 0716+714 from August 2008 to September 2013, we investigate variations in the core flux density and orientation of the sub-parsec scale jet, i.e. position angle. The γ-ray data obtained by the Fermi Large Area Telescope are used to investigate the high-energy flux variations over the same time period. For the first time in any blazar, we report a significant correlation between the γ-ray flux variations and the position angle variations in the VLBI jet. The cross-correlation analysis also indicates a positive correlation such that the mm-VLBI core flux density variations are delayed with respect to the γ-ray flux by 82±32 days. This suggests that the high-energy emission is coming from a region located ≥(3.8±1.9) parsecs upstream of the mm-VLBI core (closer to the central black hole). These results imply that the observed inner jet morphology has a strong connection with the observed γ-ray flares.
Original language | English |
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Article number | L2 |
Journal | Astronomy and Astrophysics |
Volume | 571 |
DOIs | |
State | Published - Nov 2014 |
Bibliographical note
Publisher Copyright:© 2014 ESO.
Keywords
- BL Lacertae objects: individual: S5 0716+714
- Galaxies: active
- Galaxies: jets
- Gamma rays: galaxies
- Radio continuum: galaxies