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Chemical Compositions of Population II Mid- and Late-Type Stars

Published online by Cambridge University Press:  19 July 2016

Howard E. Bond  and
R. Earle Luck
Howard E. Bond
Affiliation:
Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, Maryland 21218 USA
R. Earle Luck
Affiliation:
Department of Astronomy, Case Western Reserve University, Cleveland, Ohio 44106 USA

Abstract

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The abundance patterns in Population II red giants provide information about galactic chemical evolution and nucleosynthesis sites for various chemical elements. These patterns were first revealed by moderate-S/N photographic spectra and are now being refined and extended to additional chemical elements and fainter stars with high-S/N data. The well-established features include overabundances of O and Ca, underabundances of s-process elements, and solar ratios of heavy r-process elements. An excess of nickel found by us on moderate-S/N spectra is less certain, and should be checked with high-S/N data. New information on oxygen abundances in Population II red giants is becoming available from high-S/N observations of weak [O I] lines, and consistently indicates an oxygen overabundance due to the preferential sampling in Population II stars of ejecta from massive stars of previous generations. Recent studies of highly evolved, post-AGB Population II stars are revealing remarkable overabundances of light elements (C, N, O, and S) and deficiencies of the heaviest elements; these are probably signatures of internal nucleosynthesis followed by mixing up to, or exposure by mass loss at, the stellar surface.

Type
VI. Chemical Composition of Stars
Information
Symposium - International Astronomical Union , Volume 132: The Impact of Veryhigh S/N Spectroscopy on Stellar Physics , 1988 , pp. 477 - 484
Copyright
Copyright © Kluwer 1988 

References

Anderson, K.S., and Kraft, R.P. 1971, Ap. J., 167, 119.Google Scholar
Barbuy, B. 1983, Astr. Ap., 123, 1.Google Scholar
Barbuy, B. 1987, preprint.Google Scholar
Barker, T., et al. 1971, Ap. J., 165, 67.Google Scholar
Bond, H.E., and Luck, R.E. 1987, Ap. J., 312, 203.Google Scholar
Clegg, R., Lambert, D.L., and Tomkin, J. 1981, Ap. J., 250, 262.Google Scholar
Fahlman, G.G., Richer, H.B., and VandenBerg, D.A. 1985, Ap. J. Suppl., 58, 225.CrossRefGoogle Scholar
Gratton, R.G., and Ortolani, S. 1986, Astr. Ap., 169, 201.Google Scholar
Kodaira, K., Greenstein, J.L., and Oke, J.B. 1970, Ap. J., 159, 485.Google Scholar
Lambert, D.L. 1987, in ESO Workshop on Stellar Evolution and Dynamics in the Outer Halo of the Galaxy in press.Google Scholar
Lambert, D.L., Sneden, C., and Ries, L. 1974, Ap. J., 188, 97.Google Scholar
Leep, E., and Wallerstein, G. 1981, M.N.R.A.S., 196, 543.Google Scholar
Luck, R.E. 1981, Pub. A.S.P., 93, 211.Google Scholar
Luck, R.E., and Bond, H.E. 1983, Ap. J. (Letters), 271, L75.CrossRefGoogle Scholar
Luck, R.E., and Bond, H.E. 1984, Ap. J., 279, 729.Google Scholar
Luck, R.E., and Bond, H.E. 1985a, Ap. J., 292, 559.CrossRefGoogle Scholar
Luck, R.E., and Bond, H.E. 1985b, Ap. J. Suppl., 59, 249.CrossRefGoogle Scholar
Luck, R.E., Lambert, D.L., and Bond, H.E. 1983, Pub. A.S.P., 95, 413.Google Scholar
Peterson, R.C. 1988, this Symposium.Google Scholar
Pilachowski, C.A., Sneden, C., and Wallerstein, G. 1983, Ap. J. Suppl., 52, 241.Google Scholar
Spite, M., and Spite, F. 1985, Ann. Rev. Astr. Ap., 23, 225.CrossRefGoogle Scholar
Sneden, C., Lambert, D., and Whitaker, R. 1979, Ap. J., 234, 964.Google Scholar
Sneden, C., and Parthasarathy, M. 1983, Ap. J., 267, 757.Google Scholar
Sneden, C., and Pilachowski, C.A. 1985, Ap. J. (Letters), 288, L55.Google Scholar
Sneden, C., Pilachowski, C.A., and Krishnaswami, K. 1988, this Symposium.Google Scholar
Truran, J.W. 1981, Astr. Ap., 97, 391.Google Scholar
Truran, J.W. 1988, this Symposium.Google Scholar
Truran, J.W., and Thielemann, F.-K. 1986, in Stellar Populations, eds. Norman, C.A., Renzini, A., and Tosi, M. (Cambridge: Cambridge University Press), p. 149.Google Scholar