Reconfinement and loss of stability in jets from active galactic nuclei

Abstract

Jets powered by active galactic nuclei appear impressively stable compared with their terrestrial and laboratory counterparts—they can be traced from their origin to distances exceeding their injection radius by up to a billion times1,2. However, some less energetic jets get disrupted and lose their coherence on the scale of their host galaxy1,3. Quite remarkably, on the same scale, these jets are expected to become confined by the thermal pressure of the intra-galactic gas2. Motivated by these observations, we have started a systematic study of active galactic nuclei jets undergoing reconfinement via computer simulations. Here, we show that in the case of unmagnetized relativistic jets, the reconfinement is accompanied by the development of an instability and transition to a turbulent state. During their initial growth, the perturbations have a highly organized streamwise-oriented structure, indicating that it is not the Kelvin–Helmholtz instability, the instability which has been the main focus of the jet stability studies so far4,5. Instead, it is closely related to the centrifugal instability6. This instability is likely to be behind the division of active galactic nuclei jets into two morphological types in the Fanaroff–Riley classification7.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Fig. 1: Jet density (ρ) and Lorentz factor (Γ) for the model C1, corresponding to an FR-I jet making its way through a galactic corona.
Fig. 2: 3D rendering of model C1 at the end of the run t = 32.6 kyr.
Fig. 3: Jet density (ρ) and Lorentz factor (Γ) for the model U2, representative of an FR-II jet.
Fig. 4: 3D rendering of model U2 at the end of the run t = 32.6 kyr.

References

  1. 1.

    Begelman, M. C., Blandford, R. D. & Rees, M. J. Theory of extragalactic radio sources. Rev. Mod. Phys. 56, 255–351 (1984).

    ADS  Article  Google Scholar 

  2. 2.

    Porth, O. & Komissarov, S. S. Causality and stability of cosmic jets. Mon. Not. R. Astron. Soc. 452, 1089–1104 (2015).

    ADS  Article  Google Scholar 

  3. 3.

    Laing, R. A. & Bridle, A. H. Systematic properties of decelerating relativistic jets in low-luminosity radio galaxies. Mon. Not. R. Astron. Soc. 437, 3405–3441 (2014).

    ADS  Article  Google Scholar 

  4. 4.

    Birkinshaw, M. The Stability of Jets (Cambridge Univ. Press, Cambridge, 1991).

    Google Scholar 

  5. 5.

    Bodo, G., Mignone, A. & Rosner, R. Kelvin–Helmholtz instability for relativistic fluids. Phys. Rev. E. Stat. Nonlin. Soft. Matter Phys. 70, 036304 (2004).

    ADS  Article  Google Scholar 

  6. 6.

    Rayleigh, L. On the dynamics of revolving fluids. Proc. R. Soc. A Math. Phys. Eng. Sci. 93, 148–154 (1917).

    ADS  Article  MATH  Google Scholar 

  7. 7.

    Fanaroff, B. L. & Riley, J. M. The morphology of extragalactic radio sources of high and low luminosity. Mon. Not. R. Astron. Soc. 167, 31P–36P (1974).

    ADS  Article  Google Scholar 

  8. 8.

    Bateman, G. MHD Instabilities (MIT Press, Cambridge, Massachusetts, 1978).

    Google Scholar 

  9. 9.

    Appl, S., Lery, T. & Baty, H. Current-driven instabilities in astrophysical jets. Linear analysis. Astron. Astrophys. 355, 818–828 (2000).

    ADS  Google Scholar 

  10. 10.

    Komissarov, S. S., Porth, O. & Lyutikov, M. Stationary relativistic jets. Comput. Astrophys. Cosmol. 2, 9 (2015).

    ADS  Article  Google Scholar 

  11. 11.

    Mathews, W. G. & Brighenti, F. Hot gas in and around elliptical galaxies. Ann. Rev. Astron. Astroph. 41, 191–239 (2003).

    ADS  Article  Google Scholar 

  12. 12.

    Mart, J. M., Perucho, M. & Gómez, J. L. The internal structure of overpressured, magnetized, relativistic jets. Astrophys. J. 831, 163 (2016).

    ADS  Article  Google Scholar 

  13. 13.

    Saric, W. S. Gurtler vortices. Annu. Rev. Fluid Mech. 26, 379–409 (1994).

    ADS  Article  MATH  Google Scholar 

  14. 14.

    Gourgouliatos, K. N. & Komissarov, S. S. Relativistic centrifugal instability. Preprint at https://arxiv.org/abs/1710.01345 (2017).

  15. 15.

    Matsumoto, J. & Masada, Y. Two-dimensional numerical study for Rayleigh–Taylor and Richtmyer–Meshkov instabilities in relativistic jets. Astrophys. J. Lett. 772, L1 (2013).

    ADS  Article  Google Scholar 

  16. 16.

    Matsumoto, J., Aloy, M. A. & Perucho, M. Linear theory of the Rayleigh–Taylor instability at a discontinuous surface of a relativistic flow. Mon. Not. R. Astron. Soc. 472, 1421–1431 (2017).

    ADS  Article  Google Scholar 

  17. 17.

    Payne, D. G. & Cohn, H. The stability of confined radio jets—the role of reflection modes. Astrophys. J. 291, 655–667 (1985).

    ADS  Article  Google Scholar 

  18. 18.

    Boccardi, B. et al. The stratified two-sided jet of Cygnus A. Acceleration and collimation. Astron. Astrophys. 585, A33 (2016).

    Article  Google Scholar 

  19. 19.

    Komissarov, S. S., Barkov, M. V., Vlahakis, N. & Königl, A. Magnetic acceleration of relativistic active galactic nucleus jets. Mon. Not. R. Astron. Soc. 380, 51–70 (2007).

    ADS  Article  Google Scholar 

  20. 20.

    Tchekhovskoy, A. & Bromberg, O. Three-dimensional relativistic MHD simulations of active galactic nuclei jets: magnetic kink instability and Fanaroff–Riley dichotomy. Mon. Not. Roy. Astron. Soc. 461, L46–L50 (2016).

    ADS  Article  Google Scholar 

  21. 21.

    Falle, S. A. E. G. Self-similar jets. Mon. Not. R. Astron. Soc. 250, 581–596 (1991).

    ADS  Article  Google Scholar 

  22. 22.

    Komissarov, S. S. & Falle, S. A. E. G. The large-scale structure of FR-II radio sources. Mon. Not. R. Astron. Soc. 297, 1087–1108 (1998).

    ADS  Article  Google Scholar 

  23. 23.

    Bicknell, G. V. A model for the surface brightness of a turbulent low Mach number jet. I—theoretical development and application to 3C 31. Astrophys. J. 286, 68–87 (1984).

    ADS  Article  Google Scholar 

  24. 24.

    Komissarov, S. S. Mass-loaded relativistic jets. Mon. Not. R. Astron. Soc. 269, 394 (1994).

    ADS  Article  Google Scholar 

  25. 25.

    Giovannini, G., Cotton, W. D., Feretti, L., Lara, L. & Venturi, T. VLBI observations of a complete sample of radio galaxies: 10 years later. Astrophys. J. 552, 508–526 (2001).

    ADS  Article  Google Scholar 

  26. 26.

    Cohen, M. H. et al. Studies of the jet in Bl Lacertae. I. Recollimation shock and moving emission features. Astrophys. J. 787, 151 (2014).

    ADS  Article  Google Scholar 

  27. 27.

    Jorstad, S. G. et al. Kinematics of parsec-scale jets of gamma-ray blazars at 43 GHz within the VLBA-BU-BLAZAR program. Astrophys. J. 846, 98 (2017).

    ADS  Article  Google Scholar 

  28. 28.

    Kohler, S., Begelman, M. C. & Beckwith, K. Recollimation boundary layers in relativistic jets. Mon. Not. R. Astron. Soc. 422, 2282–2290 (2012).

    ADS  Article  Google Scholar 

  29. 29.

    Wykes, S., Hardcastle, M. J., Karakas, A. I. & Vink, J. S. Internal entrainment and the origin of jet-related broad-band emission in Centaurus A. Mon. Not. R. Astron. Soc. 447, 1001–1013 (2015).

    ADS  Article  Google Scholar 

  30. 30.

    Gopal-Krishna & Wiita, P. J. Extragalactic radio sources with hybrid morphology: implications for the Fanaroff–Riley dichotomy. Astron. Astrophys. 363, 507–516 (2000).

    ADS  Google Scholar 

  31. 31.

    Keppens, R. et al. Parallel, grid-adaptive approaches for relativistic hydro and magnetohydrodynamics. J. Comput. Phys. 231, 718–744 (2012).

    ADS  MathSciNet  Article  MATH  Google Scholar 

  32. 32.

    Porth, O., Xia, C., Hendrix, T., Moschou, S. P. & Keppens, R. MPI-AMRVAC for solar and astrophysics. Astrophys. J. Supp. Ser. 214, 4 (2014).

    ADS  Article  Google Scholar 

  33. 33.

    Harten, A., Lax, P. D. & Van Leer, B. in Upwind and High-Resolution Schemes 53–79 (Springer, Berlin Heidelberg, 1997).

  34. 34.

    Sethian, J. A. & Smereka, P. Level set methods for fluid interfaces. Ann. Rev. Fluid Mech. 35, 341–372 (2003).

    ADS  MathSciNet  Article  MATH  Google Scholar 

  35. 35.

    Perucho, M. & Mart, J. M. A numerical simulation of the evolution and fate of a Fanaroff–Riley type I jet. The case of 3C 31. Mon. Not. R. Astron. Soc. 382, 526–542 (2007).

    ADS  Article  Google Scholar 

  36. 36.

    Lohner, R. An adaptive finite element scheme for transient problems in CFD. Comp. Methods Appl. Mech. Eng. 61, 323–338 (1987).

    ADS  Article  MATH  Google Scholar 

Download references

Acknowledgements

The authors acknowledge Science and Technology Facilities Council grant ST/N000676/1. Simulations were performed on the Science and Technology Facilities Council-funded DiRAC/UK Magnetohydrodynamics Science Consortia machine, hosted as part of and enabled through the Advanced Research Computing high-performance computing resources and support team at the University of Leeds. We thank O. Porth for insightful discussions of the intricacies of AMRVAC code.

Author information

Affiliations

Authors

Contributions

Both authors contributed to planning this research and the analysis of its results. All simulations were carried out by K.N.G.

Corresponding authors

Correspondence to Konstantinos N. Gourgouliatos or Serguei S. Komissarov.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Figures 1–7 and Supplementary Table 1.

Supplementary Video 1

Supplementary Video 1.

Supplementary Video 2

Supplementary Video 2.

Supplementary Video 3

Supplementary Video 3.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Gourgouliatos, K.N., Komissarov, S.S. Reconfinement and loss of stability in jets from active galactic nuclei. Nat Astron 2, 167–171 (2018). https://doi.org/10.1038/s41550-017-0338-3

Download citation

Further reading