NUCLEOSYNTHESIS AND EVOLUTION OF MASSIVE METAL-FREE STARS

By Alexander Heger, Stan Woosley. 2008

414 citations recorded by the source corpus.

The evolution and explosion of metal-free stars with masses 10–100 M☉ 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. The amount of ionizing radiation from this generation of stars is ∼2.16 MeV per baryon (4.15 B per M☉; where 1 B = 1 Bethe = 1051 erg) for a Salpeter IMF, and may have played a role in reionizing the universe. Neglecting rotation, most of the stars end their lives as blue supergiants and form supernovae with distinctive light curves resembling SN 1987A, but some produce primary nitrogen due to dredge-up and become red supergiants. These make brighter supernovae like typical Type IIp's. For the lower mass supernovae considered, the distribution of remnant masses clusters around typical modern neutron star masses, but above 20–30 M☉, with the value depending on explosion energy, black holes are copiously formed by fallback, with a maximum hole mass of ∼40 M☉. 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. 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 1.2 B seem to be preferred in most cases.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/0731ca9b6545bd51176ed65ef37c6242fe057e7a

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. Volker Bromm
2. Stan Woosley
3. P. Hopkins
4. A. Frebel
5. S. Glover
6. L. Hernquist
7. S. Khochfar
8. Hans-Thomas Janka

Citations in the corpus

• Titans of the early Universe: The Prato statement on the origin of the first supermassive black holes (2018, methodology): “…of Carbon-Nitrogen-Oxygen (CNO) elements necessitates that the star contract until the onset of He-burning through the triple-alpha reaction, as hydrogen-burning through the ppchain alone cannot stabilise massive stars against further contraction (Heger & Woosley 2010; Kippenhahn et al. 2012).”
• The First Billion Years project: the escape fraction of ionizing photons in the epoch of reionization (2015, methodology): “For Pop II stars the abundances are calculated from yields for asymptotic giant branch stars and type Ia and type II SNe (Tornatore et al. 2007; Wiersma et al. 2009b).”
• THE MASS SPECTRUM OF THE FIRST STARS (2014, background): “…stars (Heger & Woosley 2002; Umeda & Nomoto 2002) and the abundance patterns of the metal-poor stars are well reproduced by supernova explosions of first stars as massive as the supernova progenitor stars in the present day (M 100 M ; Tominaga et al. 2007; Tominaga 2009; Heger & Woosley 2010).”
• Near-Field Cosmology with Extremely Metal-Poor Stars (2015, methodology): “Assume an average iron yield of a core-collapse supernova to be 0.1M⊙ (e.g., Heger & Woosley 2010) that is homogeneously and instantaneously mixed into a typical pristine star forming cloud of mass of 105 M⊙.”
• The First Billion Years project: the impact of stellar radiation on the co-evolution of Populations II and III (2012, methodology): “We use the same technique to model metal enrichment from Pop III stars, but we adopt the appropriate different chemical yields for type II SNe (Heger & Woosley 2010) and PISNe (Heger & Woosley 2002).”
• A simple approach to the supernova progenitor–explosion connection (2016, methodology): “We apply our model to a set of 2120 solar-metallicity progenitor models computed with an up-to-date version of the stellar evolution code K EPLER (Weaver et al. 1978; Heger & Woosley 2010).”
• Nucleosynthesis in Stars and the Chemical Enrichment of Galaxies (2013, methodology): “…and 25 M and ( from left to right) Z = 0 and 0.02, respectively, including comparisons among various models: (blue lines) Rauscher et al. (2002) and Heger & Woosley (2010); ( green lines) Limongi & Chieffi (2006, 2012); and (red lines) Kobayashi et al. (2006) and Tominaga, Umeda & Nomoto (2007).”
• CORE-COLLAPSE SUPERNOVAE FROM 9 TO 120 SOLAR MASSES BASED ON NEUTRINO-POWERED EXPLOSIONS (2015, methodology): “This star was also calculated using the KEPLER code using physics described in Heger & Woosley (2010), and, while a star of zero metallicity, it has a very similar core structure to the lightest solar-metallicity models employed here (Figure 3).”
• THE MOST METAL-POOR STARS. II. CHEMICAL ABUNDANCES OF 190 METAL-POOR STARS INCLUDING 10 NEW STARS WITH [Fe/H] ⩽ −3.5,, (2012, background): “The abundance patterns of these stars can constrain yields from zero metallicity supernovae (e.g., Limongi et al. 2003; Umeda & Nomoto 2005; Meynet et al. 2006; Tominaga et al. 2007; Heger & Woosley 2010; Limongi & Chieffi 2012).”
• THE COMPACTNESS OF PRESUPERNOVA STELLAR CORES (2013, background): “Above 50 M⊙, the compactness parameter continues to increase until about 70 M⊙, where the onset of the pulsational pair instability becomes important (Heger & Woosley 2010).”
• Chemical evolution with rotating massive star yields - I. The solar neighbourhood and the s-process elements (2018, background): “…stars (hereafter MS) for an extensive grid of isotopes (H to Zn), stellar masses and metallicities (Woosley & Weaver 1995; Limongi et al. 2000; Chieffi & Limongi 2004; Limongi & Chieffi 2012; Chieffi & Limongi 2013; Umeda & Nomoto 2002; Nomoto et al. 2006; Heger & Woosley 2010; Nomoto et al. 2013).”
• The most metal-poor damped Lyα systems: insights into chemical evolution in the very metal-poor regime★ (2011, methodology): “We also note the broad agreement between the metal-free models by Heger & Woosley (2010) and Chieffi & Limongi (2004).”
• Pulsational Pair-instability Supernovae (2016, background): “At very low metallicity, rotating models may also copiously produce primary 14N (Meynet & Maeder 2002; Heger & Woosley 2010; Yoon et al. 2012).”