Abstract
From July 13 to August 21, 1994, we observed Jupiter at 1420 MHz using one of the 30-m single dishes of the Instituto Argentino de Radioastronomía. After the impact of fragment G, we detected a rapid increase of the 21cm-continuum flux, which reached the maximum (≈ 20% of Jupiter's flux) at the end of the impact period. The nature of this radiation is clearly synchrotron. We interpret it in terms of a new population of relativistic electrons (≈ 2 × 1029) injected into the Jovian magnetosphere as a consequence of the impact explosions. The proposed mechanism is that the relativistic plasma was blown as magnetic clouds that flowed along the magnetic lines of force towards the jovimagnetic equator. We constructed a model in which the energies of the fresh electrons, generated within the magnetized clouds with a power law energy spectrum, were highly degraded by the comet dust grains attached to the magnetized plasma. The model can account for the spectral shape based on observations at several frequencies (de Pater et al., 1995, Science 268, 1879; Venturi et al., 1996, Astron. Astrophys. 316, 243). The energy released by the explosions under the form of relativistic electrons is of ≈ 2 × 1025 erg, which represents a fraction of about 1–3 per cent of the explosion energy. The efficiency in converting the explosion energy into the relativistic electron energy is, therefore, of the same order of magnitude as that of supernova explosions. An alternative model is considered. This gives figures for the total energy and number of relativistic electrons that are similar to the corresponding ones of the favoured model. Finally, we suggest that the behavior of the flux decay in the various observed frequencies is the result of the diffusion of electrons into the loss-cone due to the resonant scattering of the electrons by Alfven waves.
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References
Alfven, H.: 1981, Cosmic Plasma, D. Reidel Publishing Company.
Alfven, H. and Fälthammar, C.G.: 1963, Cosmical Electrodynamics, Oxford University Press.
Baars, J.W.M., Genzel, R., Pauliny-Toth, I.I.K. and Witzel, A.: 1977, Astron. Astrophys. 61, 99.
Behannon, K.W. and Ness, N.F.: 1967, in: R.L. Carovillano, J.F. McClay and H.R. Radoski (eds.), Physics of the Magnetosphere, Astrophys. Space Sci. Library, Vol. 10, D. Reidel Publishing Company.
Bird, M.K., Funke, O., Neidhoefer, J. and de Pater, I.: 1996, Icarus 121, 450.
Blandford, R. and Eichler, D.: 1987, Physics Reports, (Review Section of Physics Letters) 154, 1.
Bolton, S.J., Foster, R.S. and Waltman, W.B.: 1995, Geophys. Res. Lett. 22, 1801.
Brice, N. and McDonough, T.R.: 1973, Icarus 18, 206.
Brown, J.C., Craig, I.J.D. and Melrose, D.B.: 1983, Astrophys. Space Sci. 92, 105.
Chapman, C.R.: 1996, in: K.S. Noll, H.A. Weaver and P.D. Feldman (eds.), The Collision of Comet Shoemaker-Levy 9 and Jupiter, Cambridge University Press.
Chevalier, R.A. and Sarazin, C.L.: 1994, Astrophys. J. 429, 863.
Dessler, A.J. and Hill, T.L.: 1994, Geophys. Res. Lett. 21, 1043.
de Pater, I.: 1990, Annu. Rev. Astron. Astrophys. 28, 347.
de Pater, I.: 1994, Geophys. Res. Lett. 21, 1071.
de Pater, I. and Goertz, C.K.: 1994, J. Geophys. Res. 99, 2271.
de Pater, I., et al.: 1995, Science 268, 1879.
de Pater, I., van der Tak, F., Strom, R.G. and Brecht, S.H.: 1997, Icarus 129, 21.
Drainer, B.T. and Salpeter, E.E.: 1979, Astrophys. J. 231, 77.
Dulk, G.A. and Leblanc, Y.: 1995, Geophys. Res. Lett. 22, 1789.
Field, G.B., Tozzi, G.P. and Stanga, R.M.: 1995, Astron. Astrophys. 294, L53.
Galopeau, P., Gerard, E. and Lecacheux, A.: 1996, Icarus 121, 469.
Goertz, C.K., Van Allen, J.A. and Thosen, M.F.: 1979, J. Geophys. Res. 84, 87.
Ip, W.-H.: 1996, in: K.S. Noll, H.A. Weaver and P.D. Feldman (eds.), The Collision of Comet Shoemaker-Levy 9 and Jupiter, Cambridge University Press.
Kellermann, K.I. and Owen, N.F.: 1988, in: G.L. Verschuur and K.I. Kellermann (eds.), Galactic and Extragalactic Radio Astronomy, Springer-Verlag.
Klein, M.J., Gulkis, S. and Bolton, S.J.: 1995, Geophys. Res. Lett. 22, 1797.
Nicholson, P.D.: 1996, in: K.S. Noll, H.A. Weaver and P.D. Feldman (eds.), The Collision of Comet Shoemaker-Levy 9 and Jupiter, Cambridge University Press.
Martin, T.Z.: 1995, Science 268, 1875.
Melrose, D.B.: 1994, in: A.O. Benz and T.J.L. Courvoisier (eds.), Plasma Astrophysics, Saas-Fee Advanced Course 24, Springer-Verlag.
Pacholczyk, A.G.: 1970, Radio Astrophysics, Freeman and Company.
Pryor, W.R., Na, C.Y. and Gladstone, G.R.: 1994, Geophys. Res. Lett. 21, 1079.
Reich, P. and Reich, W.: 1986, Astron. Astrophys. Suppl. 63, 205.
Rohlfs, K. and Wilson, T.L.: 1996, Tools of Radio Astronomy, Springer-Verlag.
Romero, G.E., Combi, J.A. and Colomb, F.R.: 1994, Astron. Astrophys. 828, 731.
Salter, C. and Brown: 1988, in: G.L. Verschuur and K.I. Kellermann (eds.), Galactic and Extragalactic Radio Astronomy, Springer-Verlag.
Sekanina, Z.: 1996, Astron. Astrophys. 315, 315.
Smith, E.J. and Gulkis, S.: 1979, Ann. Rev. of Earth and Planetary Sci. 7.
Sukumar, S.: 1995, Astron. J. 110, 1397.
Venturi, T., et al.: 1996, Astron. Astrophys. 316, 243.
Wong, M.H., et al.: 1996, Icarus 121, 457.
Zahnle, K. and MacLow, M.M.: 1994, Icarus 108, 1.
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Olano, C. Jupiter's Synchrotron Emission Induced by the Collision of Comet Shoemaker-Levy 9. Astrophysics and Space Science 266, 347–369 (1999). https://doi.org/10.1023/A:1002020013936
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DOI: https://doi.org/10.1023/A:1002020013936