Abstract
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.
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References
Baade, W. 1956, Astrophys. J. 123, 550
Bell, A.R. 1978a, Mon. Not. R. astr. Soc. 182, 147
Biretta, J.A., Stern, C.P. and Harris, D.E. (1991), Astron. J. 101, 1632 (BSH91)
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. 159
Biretta, J. A., Zhou, F. and Owen, F. N. 1995, Astrophys. J. 447, 583
Blandford, R.D. and Rees, M.J. 1974, Mon. Not. R. astr. Soc. 169, 395
Boksenberg, A. et al. 1992, Astron. Astrophys. 261, 393
Bridle, A.H. and Perley, R.A. 1984, Ann. Rev. Astron. Astrophys. 22, 319
Burbidge, G.R. 1956, Astrophys. J. 124, 416
Carilli, C.L. and Harris, D.E. (eds.) 1996: “Cygnus A — Study of a Radio Galaxy”, Cambridge University Press, Cambridge U.K.
Curtis, H.D. 1918, Lick Obs. Publ. 13, 11
Falle, S.A.E.G. and Wilson, M.J. 1985, Mon. Not. R. astr. Soc. 216, 79
Felten, J.E. 1968, Astrophys. J. 151, 861
Hargrave, P.J. and Ryle, M. 1974, Mon. Not. R. astr. Soc. 166, 305
Hiltner, W.A. 1959 Astrophys. J. 130, 340
Hines, D.C., Owen, F.N. and Eilek, J.A. 1989, Astrophys. J. 347, 713
Keel, W.C. 1988, Astrophys. J. 329, 532
Killeen, N.E.B., Bicknell, G.V., Hyland, A.R. and Jones, T.J. 1984, Astrophys. J. 280, 126
Laing, R.A. 1980a, Mon. Not. R. astr. Soc. 193, 439
Laing, R.A. 1980b, Mon. Not. R. astr. Soc. 193, 427
Lesch, H. and Birk, G.T. 1998, Astrophys. J. 499, 167
Meisenheimer, K., Röser, H-J., Hiltner, P., Yates, M.G., Longair, M.S., Chini, R. and Perley, R.A. 1989a, Astron. Astrophys. 219, 63
Meisenheimer, K., Röser, H.-J. and Schlötelburg, M. 1989b, in E. Meurs and R. Fosbury (eds.): Extranuclear Activity in Galaxies, ESO Proceedings Garching.
Meisenheimer, K., Schlötelburg, M. and Röser, H.-J. 1996, Astron. Astrophys. 307, 61 206 237
Neumann, M. 1994: PhD Thesis, University of Heidelberg.
Neumann, M., Meisenheimer, K., Röser, H.-J. and Stickel, M. 1995: Astron. Astrophys. 296, 662–664
Neumann, M., Meisenheimer, K., Röser, H.-J. and Fink, H.H. 1997: Astron. Astrophys. 318, 383–389
Nieto, J.-L. and Lelièvre, G. 1982, Astron. Astrophys. 109, 95
Norman, M.L., Smarr, L.L., Winkler, K.-H.A. and Smith, M.D. 1982, Astron. Astrophys. 113, 285
Oort, J.H. and Walraven, T. 1956, Bull. Astron. Inst. Netherlands 12, 285
Owen, F.N., Hardee, P.E. and Bignell 1980, Astrophys. J. (Lett.) 239, L11
Owen, F.N., Hardee, P.E. and Cornwell, T.J. 1989, Astrophys. J. 340, 698 (OHC89)
Perez-Fournon, I., Colina, L., Gonzalez-Serrano, J.I. and Biermann, P.L. 1988, Astrophys. J. (Lett.) 329, L81
Perola G.C. and Tarenghi, M. 1980, Astrophys. J. 240, 447
Reid, M.J., Biretta, J.A., Junor, W. Muxlow, T.W.B. and Spencer, R.E. 1989, Astrophys. J. 336, 112
Röser, H.-J., Meisenheimer, K., Neumann, M., Conway, R.G., Davis, R.J., Perley, R.A. 1997, Reviews in Modern Astronomy 10, 253
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, 42
Scheuer, P.A.G. 1974, Mon. Not. R. astr. Soc. 166, 513
Schlötelburg, M., Meisenheimer, K. and Röser, H.-J. 1988, Astron. Astrophys. (Lett.) 202, L23
Schreier, E.J., Gorenstein, P. and Feigelson, E.D. 1982, Astrophys. J. 261, 42
Shklovsky, I.S. 1953, Doklady Akad. Nauk. U.S.S.R. 90, 983
Sparks, W.B., Fraix-Burnet, D., Machetto, F. and Owen, F.N. 1992, Nature 355, 804
Sparks, W.B., Biretta, J.A. and Machetto, F. 1996, Astrophys. J. 473, 254
Stiavelli, M., Biretta, J., Møller, P. and Zeilinger, W.W. 1992, Nature 355, 802
Stocke, J.T., Rieke, G.H. and Lebofsky, M.J. 1981, Nature 294, 319
Turland, B.D. 1975, Mon. Not. R. astr. Soc. 170, 281
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Meisenheimer, K. (1999). High-frequency observations and spectrum of the jet in M 87. In: Röser, HJ., Meisenheimer, K. (eds) The Radio Galaxy Messier 87. Lecture Notes in Physics, vol 530. Springer, Berlin, Heidelberg. https://doi.org/10.1007/BFb0106432
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DOI: https://doi.org/10.1007/BFb0106432
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