High-frequency observations and spectrum of the jet in M 87

  • Klaus Meisenheimer
Conference paper
Part of the Lecture Notes in Physics book series (LNP, volume 530)


This review collects the current fund of ground-based observations at v>1014 Hz which allows to determine the overall synchrotron spectrum of the jet in M 87 very accurately. Beyond knot D (at 3″ distance from the core), the spectrum is characterized by a straight power-law S v v −0.66 which cuts off steeply at some frequency v c The optically observed spectral variations along the jet are caused by changes in the cutoff frequency between v c =4×1015 Hz and v c =7 × 1014 Hz, while the power-law index between 1010 and 1014 Hz stays amazingly constant at α PL =−0.66±0.02. We demonstrate that an ubiquitous particle distribution function N(E)E −2.32 which cuts off steeply at a maximum energy E c =106 m e c 2, together with local variations of the magnetic field strength, accounts well for both the observed variation of v c and the apparent brightness distribution along the jet (i.e. the “knots”). The global particle spectrum might even be maintained into the inner lobes — albeit the eastern, “un-jetted” side seems to contain a steeper particle spectrum N(E)E −2.65. Thus, permanent particle re-acceleration seems required all along the jet and in the inner lobes.

Recent high-resolution observations with the HST (spatial scale ≲ 0″.1) seem to support this general behaviour of the kpc jet beyond knot D. However in the inner 300 pc from the core, rapidly evolving optical features with deviating synchrotron spectra are found. A careful analysis of their time-dependence (on time-scales comparable to the synchrotron loss-time τ syn ⋍ 10 years) might eventually help to understand the nature of the particle acceleration process. The X-ray emission from the jet is most likely of synchrotron origin. It seems to arise from compact substructures where locally the maximum particle energy is boosted above its steady state value to E c >5 × 106 m e c 2.


Surface Brightness Radio Galaxy Extragalactic Radio Source Synchrotron Spectrum High Surface Brightness 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. Baade, W. 1956, Astrophys. J. 123, 550CrossRefADSGoogle Scholar
  2. Bell, A.R. 1978a, Mon. Not. R. astr. Soc. 182, 147ADSGoogle Scholar
  3. Biretta, J.A., Stern, C.P. and Harris, D.E. (1991), Astron. J. 101, 1632 (BSH91)CrossRefADSGoogle Scholar
  4. Biretta, J.A. & Meisenheimer, K. 1993: The jet of M 87. In: “Jets in extragalactic radio sources”, proceedings of the second Ringberg workshop, eds. H.-J. Röser and K. Meisenheimer, Springer Verlag Heidelberg, Berlin, usw., p. 159CrossRefGoogle Scholar
  5. Biretta, J. A., Zhou, F. and Owen, F. N. 1995, Astrophys. J. 447, 583CrossRefADSGoogle Scholar
  6. Blandford, R.D. and Rees, M.J. 1974, Mon. Not. R. astr. Soc. 169, 395ADSGoogle Scholar
  7. Boksenberg, A. et al. 1992, Astron. Astrophys. 261, 393ADSGoogle Scholar
  8. Bridle, A.H. and Perley, R.A. 1984, Ann. Rev. Astron. Astrophys. 22, 319CrossRefADSGoogle Scholar
  9. Burbidge, G.R. 1956, Astrophys. J. 124, 416CrossRefADSGoogle Scholar
  10. Carilli, C.L. and Harris, D.E. (eds.) 1996: “Cygnus A — Study of a Radio Galaxy”, Cambridge University Press, Cambridge U.K.Google Scholar
  11. Curtis, H.D. 1918, Lick Obs. Publ. 13, 11Google Scholar
  12. Falle, S.A.E.G. and Wilson, M.J. 1985, Mon. Not. R. astr. Soc. 216, 79ADSGoogle Scholar
  13. Felten, J.E. 1968, Astrophys. J. 151, 861CrossRefADSGoogle Scholar
  14. Hargrave, P.J. and Ryle, M. 1974, Mon. Not. R. astr. Soc. 166, 305ADSGoogle Scholar
  15. Hiltner, W.A. 1959 Astrophys. J. 130, 340CrossRefADSGoogle Scholar
  16. Hines, D.C., Owen, F.N. and Eilek, J.A. 1989, Astrophys. J. 347, 713CrossRefADSGoogle Scholar
  17. Keel, W.C. 1988, Astrophys. J. 329, 532CrossRefADSGoogle Scholar
  18. Killeen, N.E.B., Bicknell, G.V., Hyland, A.R. and Jones, T.J. 1984, Astrophys. J. 280, 126CrossRefADSGoogle Scholar
  19. Laing, R.A. 1980a, Mon. Not. R. astr. Soc. 193, 439ADSGoogle Scholar
  20. Laing, R.A. 1980b, Mon. Not. R. astr. Soc. 193, 427ADSGoogle Scholar
  21. Lesch, H. and Birk, G.T. 1998, Astrophys. J. 499, 167CrossRefADSGoogle Scholar
  22. Meisenheimer, K., Röser, H-J., Hiltner, P., Yates, M.G., Longair, M.S., Chini, R. and Perley, R.A. 1989a, Astron. Astrophys. 219, 63ADSGoogle Scholar
  23. Meisenheimer, K., Röser, H.-J. and Schlötelburg, M. 1989b, in E. Meurs and R. Fosbury (eds.): Extranuclear Activity in Galaxies, ESO Proceedings Garching.Google Scholar
  24. Meisenheimer, K., Schlötelburg, M. and Röser, H.-J. 1996, Astron. Astrophys. 307, 61 206 237ADSGoogle Scholar
  25. Neumann, M. 1994: PhD Thesis, University of Heidelberg.Google Scholar
  26. Neumann, M., Meisenheimer, K., Röser, H.-J. and Stickel, M. 1995: Astron. Astrophys. 296, 662–664ADSGoogle Scholar
  27. Neumann, M., Meisenheimer, K., Röser, H.-J. and Fink, H.H. 1997: Astron. Astrophys. 318, 383–389ADSGoogle Scholar
  28. Nieto, J.-L. and Lelièvre, G. 1982, Astron. Astrophys. 109, 95ADSGoogle Scholar
  29. Norman, M.L., Smarr, L.L., Winkler, K.-H.A. and Smith, M.D. 1982, Astron. Astrophys. 113, 285ADSGoogle Scholar
  30. Oort, J.H. and Walraven, T. 1956, Bull. Astron. Inst. Netherlands 12, 285ADSGoogle Scholar
  31. Owen, F.N., Hardee, P.E. and Bignell 1980, Astrophys. J. (Lett.) 239, L11Google Scholar
  32. Owen, F.N., Hardee, P.E. and Cornwell, T.J. 1989, Astrophys. J. 340, 698 (OHC89)CrossRefADSGoogle Scholar
  33. Perez-Fournon, I., Colina, L., Gonzalez-Serrano, J.I. and Biermann, P.L. 1988, Astrophys. J. (Lett.) 329, L81Google Scholar
  34. Perola G.C. and Tarenghi, M. 1980, Astrophys. J. 240, 447CrossRefADSGoogle Scholar
  35. Reid, M.J., Biretta, J.A., Junor, W. Muxlow, T.W.B. and Spencer, R.E. 1989, Astrophys. J. 336, 112CrossRefADSGoogle Scholar
  36. Röser, H.-J., Meisenheimer, K., Neumann, M., Conway, R.G., Davis, R.J., Perley, R.A. 1997, Reviews in Modern Astronomy 10, 253ADSGoogle Scholar
  37. Salter, C.J., Chini, R., Haslam, C.G.T., Junor, W., Kreysa, E., Mezger, P.G., Spencer, R.E., Wink, J.E. and Zylka, R. 1989, Astron. Astrophys. 220, 42ADSGoogle Scholar
  38. Scheuer, P.A.G. 1974, Mon. Not. R. astr. Soc. 166, 513ADSGoogle Scholar
  39. Schlötelburg, M., Meisenheimer, K. and Röser, H.-J. 1988, Astron. Astrophys. (Lett.) 202, L23Google Scholar
  40. Schreier, E.J., Gorenstein, P. and Feigelson, E.D. 1982, Astrophys. J. 261, 42CrossRefADSGoogle Scholar
  41. Shklovsky, I.S. 1953, Doklady Akad. Nauk. U.S.S.R. 90, 983Google Scholar
  42. Sparks, W.B., Fraix-Burnet, D., Machetto, F. and Owen, F.N. 1992, Nature 355, 804CrossRefADSGoogle Scholar
  43. Sparks, W.B., Biretta, J.A. and Machetto, F. 1996, Astrophys. J. 473, 254CrossRefADSGoogle Scholar
  44. Stiavelli, M., Biretta, J., Møller, P. and Zeilinger, W.W. 1992, Nature 355, 802CrossRefADSGoogle Scholar
  45. Stocke, J.T., Rieke, G.H. and Lebofsky, M.J. 1981, Nature 294, 319CrossRefADSGoogle Scholar
  46. Turland, B.D. 1975, Mon. Not. R. astr. Soc. 170, 281ADSGoogle Scholar

Copyright information

© Springer-Verlag 1999

Authors and Affiliations

  • Klaus Meisenheimer
    • 1
  1. 1.Max-Planck-Institut für AstronomieHeidelbergGermany

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