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The Optical Radiation of Supernovae

Published online by Cambridge University Press:  12 April 2016

Robert Harkness*
Affiliation:
Department of Astronomy, University of Texas at Austin, Austin TX 78712

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Most of our knowledge of supernovae comes from studies of their optical radiation. Very high quality optical spectra have been available for several years now. The new data have aided the development of theoretical models of supernova explosions, particularly Type I events, which until recently, were very poorly understood. Type II explosions, which are believed to arise from core collapse in massive stars (Woosley, this volume;, produce optical spectra which can be simply interpreted in terms of a nearly blackbody continuum with prominent lines of hydrogen superimposed. The Type II atmosphere is of near solar composition, expanding at a characteristic velocity of 5000 km/s and at least bears some resemblance to a more familiar stellar atmosphere. Type I supernovae produce a much more violent expansion and the optical spectrum cannot be so easily accounted for. The progress made in the last few years stems mostly from the work of David Branch (Branch 1980,1981; Branch et. al. 1982,1983,1985). His synthetic spectra for Type I’s showed that the spectrum can be explained in terms of the resonance lines of mostly singly ionised metals. The lines are formed in matter moving with a bulk velocity of about 11,000 km/s and at a characteristic temperature of approximately 10,000 K. Furthermore, Branch concluded that the density profile in this region should be relatively steep and that the matter was very deficient in hydrogen and helium. As we shall see, this description fits very well with the hypothesis that Type I supernovae originate in the incineration of white dwarfs. Following the focus of recent developments this discussion will be mainly limited to the early evolution of Type I models of this kind, although many of the important features of the radiation transport are directly relevant to Type II explosions.

Type
3. Supernovae
Copyright
Copyright © Springer-Verlag 1986

References

Arnett, W.D., Branch, D., and Wheeler, J.C. 1985, Nature, 314, 337.Google Scholar
Axelrod, T.S. 1980, Ph. D. thesis, University of California, Santa Cruz.Google Scholar
Benvenuti, P., Sanz Fernandez de Cordoba, L., Wamsteker, W., Macchetto, F., Palumbo, G.C., and Panagia, N. 1982, An Atlas of UV Spectra of Supernovae (Paris: European Space Agency ESA SP-1046).Google Scholar
Branch, D. 1980, in Supernovae Spectra, eds. Meyerott, R. and Gillespie, G.H. (New York: American Institute of Physics), 39.Google Scholar
Branch, D. 1982, Ap. J., 258, 35.Google Scholar
Branch, D. 1984, In Proceedings of the Eleventh Texas Symposium on Relatlvlstlc Astrophysics, ed. Evans, D.S. (New York: N. Y. Acad of Science), 1861. Google Scholar
Branch, D., Buta, R., Falk, S.W., McCall, M.L., Sutherland, P.C., Uomoto, A., Wheeler, J.C., and Wills, B.J. 1982, Ap. J. Lett., 252, L61.CrossRefGoogle Scholar
Branch, D., and Cannon, R. 1985, In preparation.Google Scholar
Branch, D., Doggett, J.B., Nomoto, K., and Thielemann, F.-K. 1985, Ap. J., 291, 619.Google Scholar
Branch, D., Lacy, C.H., McCall, M.L., Sutherland, P.G., Uomoto, A., Wheeler, J. C., and Wills, B.J. 1983, Ap. J., 270, 123.Google Scholar
Cadonau, R., Sandage, A., and Tammann, G.A. 1985, in Supernovae as Distance Indicators, ed. Bartel, N. (Berlin: Springer-Verlag), 151.Google Scholar
Graham, J.R., Miekle, W.P.S., Allen, D.A., Longmore, A.J., and Williams, P.M. 1985, preprint.Google Scholar
Harkness, R.P. 1985, in Supernovae as Distance Indicators, ed. Bartel, N. (Berlin: Springer-Verlag), 183.CrossRefGoogle Scholar
Mihalas, D. 1980, Ap. J., 237, 574.Google Scholar
Nomoto, K., Thielemann, F.-K., and Yokoi, K. 1984, Ap. J., 286, 644.Google Scholar
Panagia, N., et. al. 1985, preprint.Google Scholar
Sutherland, P.G., and Wheeler, J.C. 1984, Ap. J., 280, 282.CrossRefGoogle Scholar
Wheeler, J.C. 1985a, in Supernovae as Distance Indicators, ed. Bartel, N. (Berlin: Springer-Verlag), 34.Google Scholar
Wheeler, J.C. 1985., In Supernovae as Distance Indicators, ed. Bartel, N. (Berlin: Springer-Verlag), 200.Google Scholar
Wheeler, J.C., and Levreault, R. 1985, Ap. J. Lett, 294, L17.Google Scholar