Superluminal Radio Features in the M87 Jet and the Site of Flaring TeV Gamma-ray Emission

Abstract

Superluminal motion is a common feature of radio jets in powerful gamma-ray emitting active galactic nuclei. Conventionally, the variable emission is assumed to originate near the central supermassive black-hole where the jet is launched on parsec scales or smaller. Here, we report the discovery of superluminal radio features within a distinct flaring X-ray emitting region in the jet of the nearby radio galaxy M87 with the Very Long Baseline Array. This shows that these two phenomenological hallmarks -- superluminal motion and high-energy variability -- are associated, and we place this activity much further (>=120 pc) from the ``central engine'' in M87 than previously thought in relativistic jet sources. We argue that the recent excess very high-energy TeV emission from M87 reported by the H.E.S.S. experiment originates from this variable superluminal structure, thus providing crucial insight into the production region of gamma-ray emission in more distant blazars.

ApJL, accepted. Massaged text and figures to fit within 4 page limit. Preprint with high-resolution figures: http://www.stanford.edu/~teddy3c/Preprints/m87vlba.pdf

References in corpus (2)

• Sub-milliarcsecond Imaging of Quasars and Active Galactic Nuclei III. Kinematics of Parsec-Scale Radio Jets
• Fast variability of TeV gamma-rays from the radio galaxy M 87

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• Production of TeV gamma-radiation in the vicinity of the supermassive black hole in the giant radiogalaxy M87
• Spine-sheath layer radiative interplay in subparsec-scale jets and the TeV emission from M87
• Observation of gamma-ray emission from the galaxy M87 above 250 GeV with VERITAS
• Recollimation and Radiative Focusing of Relativistic Jets: Applications to Blazars and M87
• Variable VHE gamma-ray emission from non-blazar AGNs
• Determination of the intrinsic velocity field in the M87 jet
• Chandra Reveals Twin X-ray Jets in the Powerful FR-II Radio Galaxy 3C353
• On the Origin of Rapid Flares in TeV Blazars
• Hubble Space Telescope observations of an extraordinary flare in the M87 jet
• A model of the TeV flare of Cygnus X-1: electron acceleration and extended pair cascades
• Gamma-Ray Emission from the Broad-Line Radio Galaxy 3C111
• A Modified Synchrotron Model for Knots in the M87 Jet
• 3C66B as a TeV radiogalaxy
• Collimation and Radiative Deceleration of Jets in TeV AGNs