J/ApJ/724/341 Nucleosynthesis of massive metal-free stars (Heger+, 2010)
Nucleosynthesis and evolution of massive metal-free stars.
Heger A., Woosley S.E.
<Astrophys. J., 724, 341-373 (2010)>
=2010ApJ...724..341H 2010ApJ...724..341H
ADC_Keywords: Models ; Stars, metal-deficient ; Supernovae ; Abundances ;
Stars, masses
Keywords: early universe - Galaxy: abundances - supernovae: general -
nuclear reactions, nucleosynthesis, abundances - stars: abundances -
stars: evolution
Abstract:
The evolution and explosion of metal-free stars with masses
10-100M☉ are followed, and their nucleosynthetic yields, light
curves, and remnant masses determined. Such stars would have been the
first to form after the big bang and may have left a distinctive
imprint on the composition of the early universe. When the supernova
yields are integrated over a Salpeter initial mass function (IMF), the
resulting elemental abundance pattern is qualitatively solar, but with
marked deficiencies of odd-Z elements with 7≤Z≤13. Neglecting the
contribution of the neutrino wind from the neutron stars that they
form, no appreciable abundances are made for elements heavier than
germanium. The computed pattern compares favorably with what has been
observed in metal-deficient stars with [Z]≲-3. For the lower mass
supernovae considered, the distribution of remnant masses clusters
around typical modern neutron star masses, but above 20-30M-☉_,
with the value depending on explosion energy, black holes are
copiously formed by fallback, with a maximum hole mass of ∼40M☉.
A novel automated fitting algorithm is developed for determining
optimal combinations of explosion energy, mixing, and IMF in the large
model database to agree with specified data sets. The model is applied
to the low-metallicity sample of Cayrel et al. (Cat. J/A+A/416/1117)
and the two ultra-iron-poor stars HE0107-5240 and HE1327-2326. Best
agreement with these very low metallicity stars is achieved with very
little mixing, and none of the metal-deficient data sets considered
show the need for a high-energy explosion component. In contrast,
explosion energies somewhat less than 1.2B seem to be preferred in
most cases.
Description:
Table 8 gives a subset of the nucleosynthesis determined for the
supernovae. It provides the ejected masses of each isotope for all
1440 explosion models with four choices of mixing (120 masses times 10
explosion energies with S/NAkB=4.0 plus two explosion energies
with pistons located at the edge of the iron core).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table8.dat 39 660546 Postsupernova yields
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See also:
J/MNRAS/412/843 : SAGA extremely metal-poor stars (Suda+, 2011)
J/A+A/524/A45 : Overproduction factors of s-nuclei in massive stars (Pumo+,
2010)
J/A+A/416/1117 : Abundances in the early Galaxy (Cayrel+, 2004)
Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 5 F5.1 Msun Mass [10/100] Progenitor mass
7- 10 F4.1 10+44J Energy [0.3/10] Explosion energy; kinetic energy at
infinity (in units of Bethe, 1051ergs)
12- 13 A2 --- Cut [S4/Ye] Initial Piston location (1)
15- 21 F7.5 --- Mixing [0/0.00251] Mixing amount; normalized to He
core (see section 4.3)
23- 27 A5 --- Isotope Isotope name
29- 39 E11.6 Msun Yield Post supernova ejecta including wind
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Note (1): Initial mass cut as follows:
S4 = Piston location: S=4 (base of O shell) or
Ye = Piston location: Iron core (drop in Ye)
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 31-Jul-2012