Abstract
We briefly review the status of models of optical flare heating by electron bombardment. We recompute Brown's (1973a) flare model atmospheres using considerably revised radiative loss rates, based on Canfield's (1974b) method applied to α, Lα, and H−. Profiles of α are computed and compared with observation. The computed profiles agree satisfactorily with those observed during the large 1972 August 7 flare, if spatial and velocity inhomogeneities are assumed. The electron injection rate inferred from α is one order of magnitude less than that inferred from hard X-rays, for this event. This may be due to either (1) the neglect of a mechanism that reduces the thick-target electron injection rate or (2) failure to incorporate important radiative loss terms.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Brown, J. C.: 1973a, Solar Phys. 31, 143.
Brown, J. C.: 1973b, Solar Phys. 29, 421.
Brown, J. C.: 1974, Solar Phys. 36, 371.
Brown, J. C.: 1975, in S. R. Kane (ed.), ‘Solar Gamma-, X-, and EUV Radiation’, IAU Symp. 68, 245.
Brown, J. C.: 1976, Phil. Trans. Roy. Soc. London 281, 473.
Canfield, R. C.: 1974a, Solar Phys. 34, 339.
Canfield, R. C.: 1974b, Astrophys. J. 194, 483.
Canfield, R. C.: 1974c, AFCRL-TR-74-0158, Environmental Research Papers, No. 471.
Cox, R. P. and Tucker, W. W.: 1969, Astrophys. J. 157, 1157.
Craig, I. J. D. and McClymont, A. N.: 1976, Solar Phys. 50, 133.
Doschek, G. A., Feldman, U., and Rosenberg, F. D.: 1977, Astrophys. J. 215, 329.
Emslie, A. G., Brown, J. C., and Donnelly, R. F.: 1978, Solar Phys. 57, 175.
Hoyng, P., Brown, J. C., and van Beek, H. F.: 1976, Solar Phys. 48, 197.
Hudson, H. S.: 1972, Solar Phys. 24, 414.
Hudson, H. S.: 1973, in R. Ramaty and R. G. Stone (eds.), High Energy Phenomena on the Sun, NASA-X-693-73-193.
Kane, S. R.: 1974, in G. A. Newkirk (ed.), ‘Coronal Disturbances’, IAU Symp. 57, 105.
Kostyuk, N. D.: 1975, Soviet Astron. AJ 19, 458.
Kostyuk, N. D.: 1976, Soviet Astron. AJ 20, 206.
Kostyuk, N. D. and Pikel'ner, S. B.: 1975, Soviet Astron. AJ 18, 590.
Lin, R. P.: 1975, Space Sci. Rev. 16, 184.
Lin, R. P. and Hudson, J. S.: 1976, Solar Phys. 50, 153.
McWhirter, R. W. P., Thonemann, P. C., and Wilson, R.: 1975, Astron. Astrophys. 40, 63.
Melrose, D. B. and Brown, J. C.: 1976, Monthly Notices Roy. Astron. Soc. 176, 15.
Nakagawa, Y., Wu, S. T., and Han, S. M.: 1973, Solar Phys. 30, 111.
Roy, J.-R.: 1976, Solar Phys. 48, 265.
Shmeleva, O. P. and Syrovatskii, S. I.: 1973, Solar Phys. 33, 341.
Tanaka, K.: 1977, personal communication.
Spicer, D. S. and Davis, J.: 1975, Solar Phys. 43, 107.
Zirin, H.: 1978, preprint.
Zirin, H. and Tanaka, K.: 1973, Solar Phys. 32, 173.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Brown, J.C., Canfield, R.C. & Robertson, M.N. Hα profiles from electron-heated solar flares. Sol Phys 57, 399–408 (1978). https://doi.org/10.1007/BF00160112
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00160112