Particle acceleration in rotating and shearing jets from AGN

Abstract

We model the acceleration of energetic particles due to shear and centrifugal effects in rotating astrophysical jets. The appropriate equation describing the diffusive transport of energetic particles in a collisionless, rotating background flow is derived and analytical steady state solutions are discussed. In particular, by considering velocity profiles from rigid, over flat to Keplerian rotation, the effects of centrifugal and shear acceleration of particles scattered by magnetic inhomogeneities are distinguished. In the case where shear acceleration dominates, it is confirmed that power law particle momentum solutions $f(p)\propto p^{-(3+\alpha )}$ exist, if the mean scattering time ${\tau }_c\propto p^{\alpha }$ is an increasing function of momentum. We show that for a more complex interplay between shear and centrifugal acceleration, the recovered power law momentum spectra might be significantly steeper but flatten with increasing azimuthal velocity due to the increasing centrifugal effects. The possible relevance of shear and centrifugal acceleration for the observed extended emission in AGN is demonstrated for the case of the jet in the quasar 3C273.

15 pages (including 8 pages Appendix), 4 figures; accepted for publication in A&A

References in corpus (4)

• Chandra Observations of the X-Ray Jet of 3C273
• HST optical spectral index map of the jet of 3C 273
• X-rays from the jet in 3C 273: clues from the radio-optical spectra
• High Energy Radiation Generated at Boundary Shear Layers of Relativistic Jets

Cited by in corpus (24)

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• Synchrotron radiation of self-collimating relativistic MHD jets
• Mrk 421 as a case study for TeV and X-ray variability in leptohadronic models
• The radio-ultraviolet spectral energy distribution of the jet in 3C273
• An Introduction to Particle Acceleration in Shearing Flows
• Generalized Fermi acceleration
• Contemporaneous observations of the radio galaxy NGC 1275 from radio to very high energy gamma-rays
• Particle Acceleration in Mildly Relativistic Shearing Flows: the Interplay of Systematic and Stochastic Effects, and the Origin of the Extended High-energy Emission in AGN Jets
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• Electron-scale shear instabilities: magnetic field generation and particle acceleration in astrophysical jets
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• Jet rotation driven by MHD shocks in helical magnetic fields
• Neutrinos from stochastic acceleration in black hole environments
• GeV-TeV gamma-rays produced by electrons in the kpc scale jet as a result of comptonization of the inner jet emission
• Pair Cascades at the Edge of the Broad-Line Region Shaping the Gamma-Ray Spectrum of 3C 279
• Particle acceleration in astrophysical shear flows
• Two blobs in a jet model for the gamma-ray emission in radio galaxies
• Linear Accelerating Superluminal Motion Model
• Absorption effects in the blazar's gamma-ray spectra due to luminous stars crossing the jet
• Very-high-energy gamma-ray detection and long-term multi-wavelength view of the flaring blazar B2 1811+31
• A one-parameter two-zone leptonic model for the blazar sequence