Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-23T19:57:50.306Z Has data issue: false hasContentIssue false
  • English
  • Français

The s-Process in AGB Stars

Published online by Cambridge University Press:  30 March 2016

R. Gallino ,
C.M. Raiteri  and
M. Busso
R. Gallino
Affiliation:
Istituto di Fisica Generale dell’Universita‘, Via P. Giuria 1, 10125 Torino, Italy
C.M. Raiteri
Affiliation:
Osservatorio Astronomico di Torino, Strada Osservatorio SO, 10025 Pino Torinese, Italy

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The evidence of an exponential distribution of neutron exposures for reproducing the solar-system s-isotopes between Zr and Pb, the main component, comes from a phenomenological analysis of the s-path in the σN versus A plot (see Käppeler, Beer and Wisshak, 1989). The resulting mean neutron exposure is τ0 = 0.30 ± 0.01 mb−1. The study of branchings with no or weak temperature dependence (95Zr; 147Nd, 147,148Pm; 185W, 186Re) allows one to derive an effective neutron density nn =(3.4±1.0)×108cm−3. On the other hand, an effective temperature is obtained from the branchings 134’135Cs, 151Sm, 154Eu and 176Lu: T8 = 3.4 ± 0.5 (Käppeler et al., 1990). Although the phenomenological approach is very useful because it is independent of stellar models, nonetheless it can only lead to effective physical conditions, symplifying the complexity of the astrophysical sites.

Type
Joint Commission Meetings
Information
Highlights of Astronomy , Volume 9: Highlights of Astronomy. As presented at the XXIst General Assembly of the IAU, 1991 , 1992 , pp. 623 - 625
Copyright
Copyright © Kluwer 1992

References

REFERENCES

Beer, H., Voß, F., and Winters, F. F. 1991, Ap. J., in pressGoogle Scholar
Boothroyd, A. I., and Sackmann, I.-J. 1988, Ap. J., 328, 653 Google Scholar
Gallino, R. 1989, in Evolution of Peculiar Red Giant Stars, Johnson, H. R. and Zuckerman, B. (eds.) (Cambridge: University Press), 176.Google Scholar
Gallino, R., Busso, , Picchio, G., and Raiteri, C.M. 1990, Nature, 348, 298 Google Scholar
Gallino, R., Busso, , Picchio, G., and Raiteri, C.M. 1991, in Chemical and Dynamical Evolution of Galaxies, (Ferrini, F., Franco, J., and Matteucci, F. (eds.), (Pisa: ETS), p. 331–332.Google Scholar
Hollowell, D.E., and Iben, I. Jr. 1988, Ap. J., 333, L25.Google Scholar
Hollowell, D. E., and Iben, I. Jr. 1989, Ap. J., 340, 966 Google Scholar
Iben, I. Jr. 1975, Ap. J., 196, 525 CrossRefGoogle Scholar
Iben, I. Jr. 1983, Ap. J., 275, L65.Google Scholar
Iben, I. Jr., and Renzini, A. 1982, Ap. J., 263, L23.Google Scholar
Iben, I. Jr., and Renzini, A. 1983, Ann. Rev. Astr. Ap., 21, 271 CrossRefGoogle Scholar
Käppeler, F., Beer, H., Wisshak, K., 1989, Rep.Prog. Phys., 52, 945.Google Scholar
Käppeler, F., Gallino, R., Busso, M., Picchio, G., and Raiteri, C. M. 1990, Ap. J., 354, 630.CrossRefGoogle Scholar
Lambert, D. L. 1988, in The Impact of Very High S/N Spectroscopy on Stellar Physics, Strobel, Cayrel de, and Spite, M. (eds.), 563.Google Scholar
Lattanzio, J. C. 1989, in Evolution of Peculiar Red Giant Stars, Johnson, H. R. and Zuckerman, B. (eds.) (Cambridge: University Press), 131.Google Scholar
Lewis, R. S., Amari, S., and Anders, E. 1990, Nature, 348, 293 Google Scholar
Raiteri, C. M., Busso, M., Gallino, R., Picchio, G., and Pulone, L. 1991a, Ap. J., 367, 228 Google Scholar
Raiteri, C. M., Busso, M., Gallino, R., and Picchio, G., 1991b, Ap. J., 371, 665 CrossRefGoogle Scholar
Smith, V. V., and Lambert, D. L. 1990, Ap. J.Suppl, 72, 387.CrossRefGoogle Scholar
Takahashi, K., and Yokoi, K. 1987, Atomic Data Nucl. Data Tables, 36, 375.CrossRefGoogle Scholar