Abstract
We investigate the possibility that strong EUV lines observed with the Goddard Solar EUV Rocket Telescope and Spectrograph (SERTS) provide good proxies for estimating the total coronal flux over shorter wavelength ranges. We use coordinated SERTS and Yohkoh observations to obtain both polynomial and power-law fits relating the broad-band soft X-ray fluxes to the intensities of Fexvi 335 Ú and 361 Ú, Fexv 284 Ú and 417 Ú, and Mgix 368 Ú measured with SERTS. We found that the power-law fits best cover the full range of solar conditions from quiet Sun through active region, though not surprisingly the ‘cooler’ Mgix 368 Ú line proves to be a poor proxy. The quadratic polynomial fits yield fair agreement over a large range for all but the Mgix line. However, the linear fits fail conspicuously when extrapolated into the quiet-Sun regime. The implications of this work for the Heii 304 Ú line formation problem are also briefly considered.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bowyer, S. and Molina, R. F.: 1991, in R. F. Molina and S. Bowyer (eds.), Extreme Ultraviolet Astronomy, Pergamon Press, New York, p. 397.
Brickhouse, N. S., Raymond, J. C., and Smith, B. W.: 1995, Astrophys. J. Suppl. Series 97, 551.
Brosius, J. W., Davila, J. M., and Thomas, R. J.: 1996, Astrophys. J. Suppl. Series 106, 143.
Cook, J. W., Cheng, C.-C., Jacobs, V. L., and Antiochus, S. K.: 1989, Astrophys. J. 338, 1176.
Davila, J. M., Thomas, R. J., Thompson, W. T., Keski-Kuha, R. A. M., and Neupert, W. M.: 1993, in E. Silver and S. Kahn (eds.), UV and X-Ray Spectroscopy of Laboratory and Astrophysical Plasma, Cambridge University Press, Cambridge, p. 301.
Falconer, D. A., Davila, J. M., and Thomas, R. J.: 1997, Astrophys. J. 482, 1050.
Jordan, C.: 1996, in S. Bowyer and R. F. Molina (eds.), Astrophysics in the Extreme Ultraviolet, Kluwer Academic Publishers, Dordrecht, Holland, p. 81.
Jordan, S. D., Thompson, W. T., Thomas, R. J., and Neupert, W. M.: 1993, Astrophys. J. 406, 346.
Thomas, R. J. and Neupert, W. M.: 1994, Astrophys. J. Suppl. 91, 461.
Thomas, R. J., Keski-Kuha, R. A. M., Neupert, W. M., Condor, C. E., and Gum, J. S.: 1991, Appl. Optics 30, 2245.
Tsuneta, S., Acton, L., Bruner, M., Lemen, J., Brown, W., Caravalho, R., Catura, R., Freedland, S., Jurcevich, B., Morrison, M., Ogawara, Y., Hirayama, T., and Owens, J.: 1991, in Z. Švestka and Y Uchida (eds.), ‘The Soft X-Ray Telescope for the Solar-A Mission’, The Yohkoh (Solar-A) Mission, Kluwer Academic Publishers, Dordrecht, Holland, p. 37.
Vaiana, G. S., Davis, J. M., Giacconi, R., Krieger, A. S., Silk, J. K., Timothy, F., and Zombeck, M.: 1973, Astrophys. J. 185, L47.
Withbroe, G. L. and Noyes, R. W.: 1977, in G. Burbidge (ed.), Ann. Rev. Astron. Astrophys. 16, 363.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Falconer, D.A., Jordan, S.D., Brosius, J.W. et al. Using Strong Solar Coronal Emission Lines as Coronal Flux Proxies. Solar Physics 180, 179–191 (1998). https://doi.org/10.1023/A:1005059816204
Issue Date:
DOI: https://doi.org/10.1023/A:1005059816204