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Evolutionary Models of Nucleosynthesis in the Galaxy

Published online by Cambridge University Press:  12 April 2016

J. W. Truran  and
A.G.W. Cameron
J. W. Truran
Affiliation:
Belfer Graduate School of Science, Yeshiva University, New York, N.Y., U.S.A.
A.G.W. Cameron
Affiliation:
Belfer Graduate School of Science, Yeshiva University, New York, N.Y., U.S.A.

Abstract

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A model of the galaxy is constructed and evolved in which the integrated influence of stellar and supernova nucleosynthesis on the composition of the interstellar gas is traced numerically. Our detailed assumptions concerning the character of the matter released from evolving stars and supernovae are guided by the results of recent stellar evolutionary calculations and hydrodynamic studies of supernova events. Stars of main sequence mass in the range 4 ≤ M ≤ 8 M⊙ are assumed to give rise to supernova events, leaving remnants we identify with neutron stars and pulsars and forming both the carbon-to-iron nuclei and the r-process heavy elements in the explosive ejection of the core material. For more massive stars, we assume the core implosion will result in the formation of a Schwarzschild singularity, that is, a black hole or ‘collapsar’. The straightforward assumptions (1) that the gas content of the galaxy decreases exponentially with time to its present level of ~ 5 % and (2) that the luminosity function characteristic of young clusters and the solar neighborhood is appropriate throughout galactic history, lead to the prediction that ≈ 20% of the unevolved stars of approximately one solar mass (M⊙) in the galaxy today should have metal compositions Z ≲ 0.1 Z⊙. As Schmidt has argued from similar reasoning, this is quite inconsistent with current observations; an early generation dominated by more massive stars – which would by now have evolved – is suggested by this difficulty. Many of these massive stars, according to our assumptions, will end their lives as collapsed black hole remnants. It is difficult to visualize an epoch of massive star formation in the collapsing gas cloud which formed our galaxy which would enrich the gas rapidly enough to account for the level of heavy element abundances in halo population stars; we have therefore proposed a stage of star formation which is entirely pregalactic in character. We suggest that the Jeans’ length-sized initial condensations in the expanding universe discussed by Peebles and Dicke may provide the appropriate setting for this first generation of stars. Guided by these considerations, and by the need for a substantial quantity of ‘unseen’ mass to bind our local group of galaxies, we have constructed a model of the galaxy in which this violent early phase of massive star formation produces both (1) approximately 25 % of the level of heavy elements observed in the solar system and (2) an enormous unseen mass in the form of black holes. The implications of our model for other features of the galaxy, including supernova nucleosynthesis, the cosmic ray production of the light elements, and cosmochronology, are discussed in detail.

Type
Research Article
Information
International Astronomical Union Colloquium , Volume 10: Gravitational N-Body Problem , November 1971 , pp. 179 - 222
Copyright
Copyright © Reidel 1971

References

Alexander, E. C. Jr., Lewis, R. S., Reynolds, J. H., and Michel, M. C.: 1971, ‘Plutonium-244: Confirmation as an Extinct Radioactivity’, preprint.Google Scholar
Arnett, W. D. : 1967, Can. J. Phys. 45,1621.CrossRefGoogle Scholar
Arnett, W. D.: 1969a, Astrophys. Space Sci. 5,180.Google Scholar
Arnett, W. D. : 1969b, Astrophys. J. 157,1369.Google Scholar
Arnett, W. D., Truran, J. W., and Woosley, S. E. : 1971, Astrophys. J. 165, 87.Google Scholar
Barkat, Z.: 1971, Astrophys. J. 163,433.Google Scholar
Barkat, Z., Buchler, J.-R. and Wheeler, J. C. : 1971, ‘Beta-Processes in Exploding Stars’, preprint.Google Scholar
Bodenheimer, P. : 1966, Astrophys. J. 144,103.Google Scholar
Burbidge, E. M. and Burbidge, G. R.: 1971, ‘The Masses of Galaxies’, in Stars and Stellar Systems, Vol. IX, Galaxies and the Universe (eds. Sandage, A. and Sandage, M.), University of Chicago Press, Chicago, to be published.Google Scholar
Burbidge, E. M., Burbidge, G. R., Fowler, W. A., and Hoyle, F. : 1957, Rev. Mod. Phys. 29, 547.Google Scholar
Buchler, J.-R., Wheeler, J. C., and Barkat, Z.: 1971, ‘Thermonuclear Detonations in Evolved Stellar Cores’, preprint.CrossRefGoogle Scholar
Cameron, A. G. W. : 1957, Chalk River Rept. CRL-41.Google Scholar
Cameron, A. G. W.: 1968, in Origin and Distribution of the Elements (ed. Ahrens, L. H.), Pergamon Press, Oxford.Google Scholar
Cameron, A. G. W. : 1970, Ann. Rev. Astron. Astrophys. 8, 179.Google Scholar
Cameron, A. G. W., Delano, M. D., and Truran, J. W. : 1970, in Proceedings of the International Conference on the Properties of Nuclei far from the Valley of Beta-Stability, Vol. 2, CERN.Google Scholar
Cameron, A. G. W. and Fowler, W. A.: 1971, Astrophys. J. 164, 111.CrossRefGoogle Scholar
Cameron, A. G. W. and Truran, J. W. : 1971, J. Roy. Astron. Soc. Can. 65,1.Google Scholar
Caughlan, G. R. and Fowler, W. A. : 1962, Astrophys. J. 136,453.CrossRefGoogle Scholar
Chandrasekhar, S.: 1939, An Introduction to the Study of Stellar Structure, University of Chicago Press, Chicago.Google Scholar
Clifford, F. E. and Taylor, R. J. : 1965, Mem. Roy. Astron. Soc. 69,21.Google Scholar
Colgate, S. A.: 1971, Astrophys. J. 163,221.CrossRefGoogle Scholar
Colgate, S. A. and White, R. H. : 1966, Astrophys. J. 143,626.CrossRefGoogle Scholar
Deutsch, A. J. : 1969, in Mass Loss from Stars (ed. Hack, M.), D. Reidel Publ. Co., Dordrecht, Holland.Google Scholar
Dicke, R. H.: 1969, Astrophys. J. 155,123.CrossRefGoogle Scholar
Ezer, D. and Cameron, A. G. W. : 1967, Can. J. Phys. 45, 3429.Google Scholar
Ezer, D. and Cameron, A. G. W. : 1971, ‘The Evolution of Hydrogen-Helium Stars’, preprint.CrossRefGoogle Scholar
Fowler, W. A. : 1971, ‘New Observations and Old Nucleocosmochronologies’, preprint.Google Scholar
Fowler, W. A., Burbidge, G. R., and Burbidge, E. M. : 1955, Astrophys. J. Suppl. 2,167.Google Scholar
Fowler, W. A., Greenstein, J. L., and Hoyle, F. : 1962, Geophys. J. 6,148.Google Scholar
Gunn, J. E. and Ostriker, J. P. : 1970, Astrophys. J. 160,979.Google Scholar
Hansen, C. J. and Wheeler, J. C. : 1969, Astrophys. Space Sci. 3,464.CrossRefGoogle Scholar
Hayashi, C., Hoshi, R., and Sugimoto, D. : 1962, Prog. Theor. Phys. Suppl. 22,1.CrossRefGoogle Scholar
Henyey, L. G., LeLevier, R., and Levee, R. D. : 1959, Astrophys. J. 129,2.CrossRefGoogle Scholar
Hirasawa, T.: 1971, ‘Formation of Protogalaxies and Molecular Processes in Hydrogen Gas’, preprint.Google Scholar
Hohenberg, C. M.: 1969, Science 166,212.Google Scholar
Iben, I. Jr. : 1965, Astrophys. J. 142,1447.CrossRefGoogle Scholar
Iben, I. Jr.: 1966a, Astrophys. J. 143,483.CrossRefGoogle Scholar
Iben, I. Jr. : 1966b, Astrophys. J. 143, 505.Google Scholar
Iben, I. Jr.: 1966c, Astrophys. J. 143, 516.CrossRefGoogle Scholar
Iben, I. Jr.: 1967a, Astrophys. J. 147, 624.CrossRefGoogle Scholar
Iben, I. Jr.: 1967b, Astrophys. J. 147, 650.CrossRefGoogle Scholar
Iben, I. and Rood, R. D. : 1970, Astrophys. J. 161, 587.Google Scholar
Kodaira, K., Greenstein, J. L., and Oke, J. B. : 1970, Astrophys. J. 159,485.Google Scholar
King, I. R. : 1967, Draft Report I. A.U., p. 846.Google Scholar
King, I. R.: 1968, Astron. J. 71,276.Google Scholar
Kuhi, L. R. : 1966, Astrophys. J. 143,991.Google Scholar
Larson, R. B. and Starrfield, S.: 1971, ‘On the Formation of Massive Stars and the Upper Limit of Stellar Masses’, preprint.Google Scholar
LeBlanc, J. M. and Wilson, J. R.: 1970, Astrophys. J. 161, 541.CrossRefGoogle Scholar
Limber, D. N.: 1960, Astrophys. J. 131,168.Google Scholar
McClure, R. D. and van den Bergh, S. : 1968, Astron. J. 73, 313.CrossRefGoogle Scholar
Mitler, H. E. : 1967, in High Energy Reactions in Astrophysics (ed. Shen, B. S.P.), W. J. Benjamin, Inc., New York.Google Scholar
Mitler, H. E. : 1970, Smithsonian Astrophysical Observatory, Special Report No. 330.Google Scholar
Oort, J. H. : 1970, Astron. Astrophys. 7, 381.Google Scholar
Paczynski, B. : 1970, Acta Astron. 20,47.Google Scholar
Page, T. : 1965, Smithsonian Astrophysical Observatory, Special Report No. 195.Google Scholar
Pagel, B. E. J.: 1968, in Origin and Distribution of the Elements (ed. Ahrens, L. H.), Pergamon Press, Oxford.Google Scholar
Partridge, R. B. and Peebles, P. J. E. : 1967, Astrophys. J. 148, 377.Google Scholar
Peebles, P. J. E.: 1969, Astrophys. J. 155, 393.Google Scholar
Peebles, P. J. E. : 1971, Astron. Astrophys. 11, 377.Google Scholar
Peebles, P. J. E. and Dicke, R.: 1968, Astrophys. J. 154, 891.Google Scholar
Podosek, F. A. : 1970, Earth Planet, Sci. Letters 8,183.Google Scholar
Reeves, H., Fowler, W. A., and Hoyle, F. : 1969, Nature 226,727.CrossRefGoogle Scholar
Rose, W. K.: 1966, Astrophys. J. 146, 838.Google Scholar
Rose, W. K. : 1967, Astrophys. J. 150,193.CrossRefGoogle Scholar
Rose, W. K. : 1969, Astrophys. J. 155,491.Google Scholar
Salpeter, E. E.: 1955, Astrophys. J. 121,161.Google Scholar
Salpeter, E. E.: 1959, Astrophys. J. 129, 608.Google Scholar
Sandage, A. R.: 1957, Astrophys. J. 125,422.CrossRefGoogle Scholar
Sanders, R. H. : 1967, Astrophys. J. 150,971.Google Scholar
Schmidt, M. : 1959, Astrophys. J. 129, 243.CrossRefGoogle Scholar
Schmidt, M. : 1963, Astrophys. J. 137, 758.CrossRefGoogle Scholar
Schramm, D. N. and Wasserburg, G. R. : 1970, Astrophys. J. 162, 57.Google Scholar
Schwarzschild, M. and Harm, R. : 1958, Astrophys. J. 128, 348.Google Scholar
Schwarzschild, M. and Harm, R. : 1965, Astrophys. J. 142, 855.Google Scholar
Schwarzschild, M. and Harm, R. : 1967, Astrophys. J. 150,961.Google Scholar
Schwarzschild, M. and Spitzer, L.: 1953, Observatory 73, 77.Google Scholar
Seeger, P. A. : 1970, in Proceedings of the International Conference on the Properties of Nuclei far from the Valley of Beta-Stability, Vol. 1, CERN.Google Scholar
Seeger, P. A., Fowler, W. A. and Clayton, D. D. : 1965, Astrophys. J. Suppl. 97,121.Google Scholar
Seeger, P. A. and Schramm, D. N. : 1970, Astrophys. J. 160, L157.Google Scholar
Shklovsky, I. S.: 1968, Supernovae, Wiley and Sons, London.Google Scholar
Simoda, M. and Kimura, H. : 1968, Astrophys. J. 151,133.Google Scholar
Spinrad, H. : 1966, Publ. Astron. Soc. Pacific 78, 367.Google Scholar
Spinrad, H., Greenstein, J. L., Taylor, B. J., and King, I. R. : 1970, Astrophys. J. 162,891.Google Scholar
Spinrad, H. and Taylor, B. J. : 1969, Astrophys. J. 157,1279.Google Scholar
Tammann, G. A. : 1970, Astron. Astrophys. 8,458.Google Scholar
Truran, J. W. and Arnett, W. D.: 1970, Astrophys. J. 160,181.CrossRefGoogle Scholar
Truran, J. W., Arnett, W. D. and Cameron, A. G. W. : 1967, Can. J. Phys. 45,2315.Google Scholar
Truran, J. W. and Cameron, A. G. W. : 1970, Nature 225,710.Google Scholar
Truran, J. W., Cameron, A. G. W., and Hilf, E.: 1970, in Proceedings of the International Conference on the Properties of Nuclei far from the Valley of Beta-Stability, Vol. 1, CERN.Google Scholar
Truran, J. W., Hansen, C. J., and Cameron, A. G. W. : 1965, Can. J. Phys. 43,1616.Google Scholar
Van den Bergh, S. : 1957, Astrophys. J. 125,445.Google Scholar
Wagoner, R. V., Fowler, W. A., and Hoyle, F. : 1967, Astrophys. J. 148, 3.Google Scholar
Wallerstein, G., Greenstein, J. L., Parker, R., Helper, H. L., and Aller, L. H.: 1963, Astrophys. J. 137,280.Google Scholar
Wasserburg, G. J., Huneke, J. C., and Burnett, D. S. : 1969, J. Geophys. Res. 74,4221.Google Scholar
Wasserburg, G. J., Schramm, D. N., and Huneke, J. C.: 1969, Astrophys. J. 157, L91.Google Scholar
Weigert, A. : 1966, Z. Astrophys. 64, 395.Google Scholar
Wheeler, J. C., Barkat, Z. and Buchler, J.-R. : 1970, Astrophys. J. Letters 162, L129.Google Scholar
Wheeler, J. C. and Hansen, C. J. : 1971, Astrophys. Space Sci. 11, 373.Google Scholar
Wilson, J. R.: 1971, Astrophys. J. 163,209.Google Scholar
Wyller, A. A. : 1970, Astrophys. J. 160,443.CrossRefGoogle Scholar
Ziebarth, K.: 1970, Astrophys. J. 162,947.CrossRefGoogle Scholar