Resonant Kelvin-Helmholtz modes in sheared relativistic flows.

Certain aspects of the (linear and nonlinear) stability of sheared relativistic (slab) jets are analyzed. The linear problem has been solved for a wide range of jet models well inside the ultrarelativistic domain (flow Lorentz factors up to 20, specific internal energies approximately 60c2). As a distinct feature of our work, we have combined the analytical linear approach with high-resolution relativistic hydrodynamical simulations, which has allowed us (i) to identify, in the linear regime, resonant modes specific to the relativistic shear layer, (ii) to confirm the result of the linear analysis with numerical simulations, and (iii) more interestingly, to follow the instability development through the nonlinear regime. We find that very-high-order reflection modes with dominant growth rates can modify the global, long-term stability of the relativistic flow. We discuss the dependence of these resonant modes on the jet flow Lorentz factor and specific internal energy and on the shear-layer thickness. The results could have potential applications in the field of extragalactic relativistic jets.

[1]  M. Perucho,et al.  Nonlinear stability of relativistic sheared planar jets , 2005, astro-ph/0510426.

[2]  J. Martí,et al.  Stability of hydrodynamical relativistic planar jets - II. Long-term nonlinear evolution , 2004, astro-ph/0407574.

[3]  J. Martí,et al.  Stability of hydrodynamical relativistic planar jets. I. Linear evolution and saturation of Kelvin-Helmholtz modes , 2004, astro-ph/0407548.

[4]  P. Hardee,et al.  Internal structure and dynamics of the kiloparsec-scale jet in M87 , 2003 .

[5]  J. A. Miralles,et al.  Stability analysis of relativistic jets from collapsars and its implications on the short-term variability of gamma-ray bursts , 2002 .

[6]  Nrao,et al.  Dynamical models for jet deceleration in the radio galaxy 3C 31 , 2002, astro-ph/0207427.

[7]  Nrao,et al.  Relativistic models and the jet velocity field in the radio galaxy 3C 31 , 2002, astro-ph/0206215.

[8]  V. Urpin.  Instability of relativistic sheared jets and distinction between FRI and FRII sources , 2002 .

[9]  A. Lobanov,et al.  A Cosmic Double Helix in the Archetypical Quasar 3C273 , 2001, Science.

[10]  J. Benson,et al.  The Structure and Motions of the 3C 120 Radio Jet on Scales of 0.6-300 Parsecs , 2001, astro-ph/0103379.

[11]  E.P.J. van den Heuvel,et al.  Black holes in binaries and galactic nuclei , 2001 .

[12]  M. Aloy,et al.  Jet Stability and the Generation of Superluminal and Stationary Components , 2001, astro-ph/0101188.

[13]  P. Hardee,et al.  Relativistic Jet Response to Precession and Wave-Wave Interactions , 2000, astro-ph/0103224.

[14]  P. Hardee.  On Three-dimensional Structures in Relativistic Hydrodynamic Jets , 2000 .

[15]  D. H. Roberts,et al.  Radio Jet-Ambient Medium Interactions on Parsec Scales in the Blazar 1055+018 , 1999, astro-ph/9903330.

[16]  P. Hardee,et al.  A Comparison of the Morphology and Stability of Relativistic and Nonrelativistic Jets , 1999, astro-ph/9901046.

[17]  S. Baum,et al.  Internal Structure of the Jets in 3C 353 , 1998 .

[18]  M. Hardcastle.  Energy transport in radio galaxies and quasars , 1997 .

[19]  Antonio Marquina,et al.  Morphology and Dynamics of Relativistic Jets , 1997 .

[20]  France.,et al.  Kelvin-Helmholtz instability of stratified jets , 1996, astro-ph/9604156.

[21]  M. Norman,et al.  Instabilities in astrophysical jets. I: Linear analysis of body and surface waves , 1992 .

[22]  M. Birkinshaw.  The Kelvin–Helmholtz instability for relativistic particle beams – II. Flows bounded by a simple shear layer , 1991 .

[23]  William H. Press,et al.  Numerical recipes , 1990 .

[24]  M. Norman,et al.  The Role of Oblique Reflection Shocks in Astrophysical Jets , 1989 .

[25]  P. Hardee.  Spatial Stability of Relativistic Jets: Application to 3C 345 , 1987 .

[26]  P. Hardee.  Spatial Stability of Jets: The Nonaxisymmetric Fundamental and Reflection Modes , 1987 .

[27]  S. R. Choudhury,et al.  On the Kelvin-Helmholtz instabilities of supersonic shear layers , 1984 .

[28]  M. Birkinshaw.  The Kelvin–Helmholtz instability for relativistic particle beams – I. Stability analyses in the time and space domains for vortex-sheet flows , 1984 .

[29]  A. Ferrari,et al.  Magnetohydrodynamic Kelvin–Helmholtz instabilities in astrophysics – III. Hydrodynamic flows with shear layers , 1982 .

[30]  P. Hardee.  Fluid dynamical twisting of the radio jets in 3C 449 , 1981 .

[31]  P. Hardee.  On the configuration and propagation of jets in extragalactic radio sources , 1979 .

[32]  P. Drazin,et al.  Shear layer instability of an inviscid compressible fluid. Part 3 , 1977, Journal of Fluid Mechanics.

[33]  P. Scheuer,et al.  Instabilities of Kelvin–Helmholtz type for Relativistic streaming , 1976 .

[34]  R. Blandford,et al.  Kelvin–Helmholtz Instability of Relativistic Beams , 1976 .

[35]  J. Riley,et al.  The Morphology of Extragalactic Radio Sources of High and Low Luminosity , 1974 .

[36]  J. Ables,et al.  Simultaneous observations of pulsar intensity variations at Parkes and Ootacamund. , 1974 .

[37]  Gerwin.  A BRIEF REVIEW OF THE LITERATURE CONCERNING THE STABILITY OF THE INTERFACE BETWEEN TWO FLUIDS IN RELATIVE MOTION. , 1968 .

[38]  A. E. Gill.  Instabilities of ``Top‐Hat'' Jets and Wakes in Compressible Fluids , 1965 .

[39]  R. A. Wentzell,et al.  Hydrodynamic and Hydromagnetic Stability. By S. CHANDRASEKHAR. Clarendon Press: Oxford University Press, 1961. 652 pp. £5. 5s. , 1962, Journal of Fluid Mechanics.