Abstract
With the use of the empirical equations for the binding and internal energies of heavy nuclides with density dependence, the abundance distribution of neutron-excess nuclides which appear up to some subnuclear density along the collapsing trajectory of a stellar core is calculated with an assumption of the β-equilibrium condition. Free nucleons are simply assumed to be non-interacting, degenerate fermions. Using the abundance distribution thus derived, the quantities affecting the hydrodynamics of the core, such as the average mass number and the mass fraction of heavy nuclides, the mass fraction of free neutrons, the number of electrons per baryon, the average excitation energy per nucleus, and the entropy, the pressure and the adiabatic index of the system are then calculated. It is found that we can obtain fairly reliable values of these physical quantities by introducing only the magic and near-magic number nuclides in the calculation, and that the results are hardly affected by the difference of the semi-empirical nuclear mass formula we use to derive the binding energies of unknown nuclides and the formula of the grand partition function of these nuclides.
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References
Arnett, W. D.: 1977,Astrophys. J. 218, 815.
Barranco, M. and Buchler, J. R.: 1980,Phys. Rev. C22, 1729.
Barranco, M. and Buchler, J. R.: 1981a,Astrophys. J. 245, L109.
Barranco, M. and Buchler, J. R.: 1981b,Phys. Rev C24, 1191.
Baym, G. and Pethick, C. J.: 1975,Ann. Rev. Nucl. Sci. 25, 82 (and references therein).
Baym, G., Bethe, H. A., and Pethick, C. J.: 1971,Nucl. Phys A175, 225.
Bethe, H. A., Brown, G. E., Applegate, J., and Lattimer, J. M.: 1979,Nucl. Phys. A 324, 487.
Bruenn, S. W., Arnett, W. D., and Schramm, D. N.: 1977,Astrophys. J. 213, 213.
Buchler, J. R. and Coon, S. A.: 1977,Astrophys. J. 212, 807.
El Eid, M. F. and Hilf, E. R.: 1977,Astron. Astrophys. 57, 243.
El Eid, M. F. and Hillebrandt, W.: 1980,Astron. Astrophys. Suppl. Ser. 42, 215.
Epstein, R. I. and Pethick, C. J.: 1981,Astrophys J. 243, 1003.
Garvey, G. T., Gerace, W. J., Jaffe, R. L., Talmi, I., and Kelson, I.: 1969,Rev. Mod. Phys. 41, S1.
Gilbert, A. and Cameron, A. G. W.: 1965,Can. J. Phys. 43, 1446.
Hansen, J. P.: 1973,Phys. Rev A8, 3096.
Hillebrandt, W. and Müller, E.: 1981, MPI-PAE/Astro 253.
Klapdor, H. V., Oda, T., Metzinger, J., Hillebrandt, W., and Thielemann, F. K.: 1981,Z. Phys. A299, 213.
Küpper, W. A., Wegmann, G., and Hilf, E. R.: 1974,Ann. Phys. 88, 454.
Lamb, D. Q., Lattimer, J. M., Pethick, C. J., and Ravenhall, D. G.: 1978,Phys. Rev. Letters 41, 1623.
Lamb, D. Q., Lattimer, J. M., Pethick, C. J., and Ravenhall, D. G.: 1981,Nucl. Phys. A360, 459.
Lattimer, J. M. and Ravenhall, D. G.: 1978,Astrophys. J. 223, 314.
Mazurek, T. J. and Brown, G. E.:Astron. Astrophys. 81, 382.
Mazurek, T. J., Lattimer, J. M., and Brown, G. E.: 1979,Astrophys. J. 229 713.
Murphy, M. J.: 1980,Astrophys. J. Suppl. 42, 385.
Ohnishi, T.: 1982, submitted for publication.
Seeger, P. A. and Howard, W. M.: 1974, LA-5750.
Seeger, P. A. and Howard, W. M.: 1976,Atom., Data. Nucl. Data Tables 17, 428.
Von Groote, H., Hilf, E. R., and Takahashi, K.: 1976,Atom. Data Nucl. Data Tables 17, 418.
Weaver, T. A., Zimmermann, B., and Woosley, S. E.: 1978,Astrophys. J. 225, 1021.
Wilson, J. R.: 1980,Ann. N. Y. Acad. Sci. 336, 358.
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Ohnishi, T. Abundance distribution of heavy nuclides up to a subnuclear density and the equation of state for gravitationally collapsing stars. Astrophys Space Sci 85, 243–262 (1982). https://doi.org/10.1007/BF00653446
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DOI: https://doi.org/10.1007/BF00653446