Abstract
Observations of an energy-dependent asymmetry in footpoint hard X-ray emission by RHESSI for the M4.0 solar flare of 17 March 2002 allows us to probe the dynamics of particle transport with energy and time. The presence of such an asymmetry is most readily explained by the effects of a converging magnetic field with different rates of convergence at the different footpoints, as would be expected from realistic surface field distributions. Such a geometry has been discussed in the context of a trap-plus-precipitation model where the transport of energetic particles in the flare is governed by the precipitation out of the coronal trap via collisions, wave-particle interactions or some other scattering process, into the high-density chromosphere. Comparison of RHESSI observations with a trap-plus-precipitation model allows us to use the energy dependence of the asymmetry and the observed ratio of footpoint to coronal emission at the different energies to assess the role of the trapping in the transport of energetic electrons and to probe the nature of the particle precipitation process inside the loss cone.
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References
DAlexander, D.: 1990, Astron. Astrophys. 235, 431.
Alexander, D. and Metcalf, T. R.: 1997, Astrophys. J. 489, 442.
Antonucci, E. et al.: 1998, in J. L. R. Saba, B. M. Haisch, and J. T. Schmelz (eds.), ‘Flare Dynamics’, The Many Faces of the Sun, pp. 331–393.
Aschwanden, M. J.: 2002, Space Sci. Reviews 101, 1.
Aschwanden, M. J., Fletcher, L., Sakao, T., Kosugi, T., and Hudson, H.: 1999, Astrophys. J. 517, 977.
Aschwanden, M. J., Hudson, H. S., Kosugi, T., and Schwartz, R. A.: 1996, Astrophys. J. 464, 985.
Bai, T. and Dennis, B. R.: 1985, Astrophys. J. 292, 699.
Bai, T. and Ramaty, R.: 1979, Astrophys. J. 227, 1072.
Bai, T., Hudson, H. S., Pelling, R. M., Lin, R. P., Schwartz, R. A., and von Rosenvinge, T. T.: 1983, Astrophys. J. 267, 433.
Brown, J. C.: 1971, Solar Phys. 18, 489.
Emslie, A. G. and Alexander, D.: 1987, Solar Phys. 110, 295.
Holman, G. D.: 1985, Astrophys. J. 293, 584.
Fishman, G. J., Meegan, C. A., Wilson, R. B., Paciesas, W. S., and Pendleton, G. N.: 1992,'The BATSE Experiment on the Compton Gamma Ray Observatory: Status and some Early Results', The Compton Observatory Science Workshop, pp. 26–34.
Kane, S.: 1983, Solar Phys. 86, 355.
Kennel, C. F. and Petschek, H. E.: 1966, J. Geophys. Res. 71, 1.
Kosugi T. et al.: 1991, Solar Phys. 136, 17.
Krucker, S. and Lin, R. P.: 2002, Solar Phys. (this volume).
LaRosa, T. N. and Emslie, A. G.: 1988, Astrophys. J 326, 997.
Lin R. P. et al.: 2002, Solar Phys., this volume.
MacKinnon, A. L.: 1986, Astron. Astrophys. 163, 2391.
MacKinnon, A. L.: 1988, Astron. Astrophys. 194, 279.
MacKinnon, A. L.: 1991, Astron. Astrophys. 242, 256.
Masuda, S., Kosugi, T., Hara, H., Tsuneta, S., and Ogawara, Y.: 1994, Nature 371, 495.
McClements, K. G.: 1990a, Astron. Astrophys. 230, 213.
McClements, K. G.: 1990b, Astron. Astrophys. 234, 487.
McClements, K. G.: 1992, Astron. Astrophys. 253, 261.
McClements, K. G. and Alexander, D.: 1989, Solar Phys. 123, 161.
Melrose, D. B. and Brown, J. C.: 1976, Monthly Notices Royal Astron. Soc. 176, 15.
Metcalf, T. R. and Alexander, D.: 1999, Astrophys. J. 522, 1108.
Metcalf, T. R., Hudson, H. S., Kosugi, T., Puetter, R. C., and Piña, R. K.: 1996, Astrophys. J. 466, 585.
Ramaty, R., Schwartz, R. A., Enome, S., and Nakajima, H.: 1985, Astrophys. J. 436, 941.
Scherrer, P. et al.: 1995, Solar Phys. 162, 129.
Takakura, T. and Kai, K.: 1966, Publ. Astron. Soc. Japan 18, 57.
Takakura, T., Tanaka, K., Nitta, N., Kai, K., and Ohki, K.: 1987, Solar Phys. 107, 109.
Tsuneta, S. and Naito, T.: 1998, Astrophys. J. 495, L67.
Tsuneta, S. et al.: 1984, Astrophys. J. 280, 887.
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Alexander, D., Metcalf, T.R. Energy dependence of electron trapping in a solar flare. Sol Phys 210, 323–340 (2002). https://doi.org/10.1023/A:1022457413628
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DOI: https://doi.org/10.1023/A:1022457413628