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Formation of Line Spectra—A Review

Published online by Cambridge University Press:  25 April 2016

J. T. Jefferies*
Affiliation:
Institute for Astronomy, University of Hawaii

Extract

A typical stellar spectrogram shows a vast number of spectral lines. Each of these has its characteristic shape and strength which must, in some way, reflect the structure of the atmosphere in which the radiation arose. It seems reasonable that from all this profile data we should be able (and with considerable redundancy) to infer a good deal about the physical structure of the radiating gas, and a major effort has correspondingly been devoted to clarifying the physical basis of spectral line formation, i.e., exactly how the atmospheric structure and the atomic properties are reflected in the line profiles. This problem, however, is far from solved : Few, if any, of the profiles of strong lines can be predicted in detail from model atmospheres, nor have analyses of the profiles yielded unambiguous data on the atmospheric structure. Indeed, as recently as 1967, the participants at a conference in Bilderberg (Holland) concluded that no data at all which had been obtained from line profile analyses was worthy of inclusion in specifying the solar atmospheric model. Evidently, then, the problem of line formation is not trivial ; in this paper we discuss some of the difficulties and review the not inconsiderable progress which has been made in this area of astrophysical research.

Type
Invited Papers
Copyright
Copyright © Astronomical Society of Australia 1970

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References

1 Jefferies, J. T., ‘Spectral Line Formation’, Blaisdell Publishing Company, Waltham, Massachusetts 1968.Google Scholar
2 Thomas, R. N., ‘Some Aspects of Non-Equilibrium Thermodynamics in the Presence of a Radiation Field’, University of Colorado Press, Colorado 1965.Google Scholar
3 Henyey, L. G., Proc. Nat. Acad. Sci., 26, 50 (1940).Google Scholar
4 Thomas, R. N., Ap. J., 125, 260 (1957).CrossRefGoogle Scholar
5 Jefferies, J. T. and White, O. R., Ap. J., 132, 767 (1960).Google Scholar
6 Jefferies, J. T., FQSRT, 3, 217 (1963).Google Scholar
7 Finn, G. D. and Jefferies, J. T., JQSRT, 8, 1675 (1968).Google Scholar
8 Dumont, S., ‘Resonance Lines in Astrophysics’, NCAR, Colorado 1968 p.341.Google Scholar
9 Cuny, Y., ‘Resonance Lines in Astrophysics’, NCAR, Colorado1 1968, p.202.Google Scholar
10 Jefferies, J. T. and Thomas, R. N., Ap. J., 127, 667 (1958).CrossRefGoogle Scholar
11 Jefferies, J. T. and Thomas, R. N., Ap. J., 129, 401 (1959).CrossRefGoogle Scholar
12 Jefferies, J. T. and Thomas, R. N., Ap. J., 131, 695 (1960).Google Scholar
13 Avrett, E. H. and Hummer, D.G., MNRAS, 130, 295 (1965).CrossRefGoogle Scholar
14 Hummer, D. G. and Rybicki, G. B., ‘Methods in Computational Physics’, 7, 53, Academic Press, New York 1967.Google Scholar
15 Finn, G. D. and Jefferies, J. T., JQSRT, 8, 1705 (1968).Google Scholar
16 Waddell, J. H., Ap. J., 136, 231 (1962).CrossRefGoogle Scholar
17 Avrett, E. H., Ap. J., 144, 59 (1966).Google Scholar
18 Finn, G. D. and Jefferies, J. T., JQSRT, 9, 469 (1969).CrossRefGoogle Scholar
19 Rybicki, G. B., Smithson. Astrophys. Obs. Sp. Report No. 180 (1965).Google Scholar
20 Rybicki, G. B., IAU Symposium No. 28, 1967, p.471.Google Scholar
21 Wilson, P. R., Ap. J., 151, 1019 (1968).Google Scholar
22 Wilson, P. R., Ap. J., 151, 1029 (1968).Google Scholar
23 Giovanelli, R. G., Aust. J. Phys., 12, 164 (1959).CrossRefGoogle Scholar
24 Jones, H. P. and Skumanich, A., ‘Resonance Lines in Astrophysics’, NCAR, Colorado 1968, p.79.Google Scholar
25 House, L. L. and Avery, L. W., JQSRT, 9, 1579 (1969).Google Scholar
26 Fymat, A. L. and Abhyankar, K. D., Ap. J., 158, 315 (1969).Google Scholar
27 Chamaraux, P., Ann. d’ap., 30, 67 (1967).Google Scholar
28 Avrett, E. H., private communication.Google Scholar
29 Athay, R. G. and Canfleld, R. C., Ap. J., 156, 695 (1969).CrossRefGoogle Scholar
30 Cuny, Y., Solar Physics, 3, 204 (1968).Google Scholar
31 Wilson, O. C. and Bappu, M. K. V., Ap. J., 125, 661 (1957).Google Scholar
32 Wilson, O. C., Ap. J., 138, 832 (1963).Google Scholar
33 Wilson, O. C. and Skumanich, A., Ap. J., 140, 1401 (1964).CrossRefGoogle Scholar
34 Zirker, J. B., Solar Physics, 3, 164 (1968).Google Scholar
35 Engvold, O., Astrophys. Nora., 10, 101 (1966).Google Scholar
36 Dumont, S., Ann. d’ap., 30, 421, 861 (1967).Google Scholar
37 Athay, R. G. and Skumanich, A., Solar Physics, 3, 204 (1968).Google Scholar
38 Linsky, J. L., ‘Resonance Lines in Astrophysics’, NCAR, Colorado 1968, p.441.Google Scholar
39 Beebe, H. A. and Johnson, H. R., Solar Physics, 10, 79 (1969).CrossRefGoogle Scholar
40 Avrett, E. H. and Linsky, J. L., private communication.Google Scholar
41 De Jager, C. and Neven, L., Solar Physics, 1, 27 (1967).Google Scholar
42 Curtis, W. M. and Jefferies, J. T., Ap. J., 150, 1061 (1967).Google Scholar
43 Altrock, R. C., Solar Physics, 5, 260 (1968).CrossRefGoogle Scholar
44 Wilson, A. M. and Worrall, G., Astron. Astrophys., 2, 469 (1969).Google Scholar