Effects of rotation on the evolution of primordial stars

By S. Ekström, G. Meynet, C. Chiappini, R. Hirschi, Andre Maeder. 2008

180 citations recorded by the source corpus.

Context. Though still beyond our observational abilities, Populati on III stars are interesting objects in many perspectives. T hey are responsible for the re-ionisation of the inter-galactic me dium. They also left their chemical imprint in the early Universe, imprint which can be deciphered in the most metal-poor stars in the halo of our Galaxy. Aims. Rotation has been shown to play a determinant role at very low metallicity, bringing heavy mass loss where almost none was expected. Is this still true when the metallicity strictly e quals zero? The aim of our study is to get an answer to this question, and to determine how rotation changes the evolution and the chemical signature of the primordial stars. Methods. We have calculated seven differentially-rotating stellar models at zero metallicity, w ith masses between 9 and 200 M⊙. For each mass, we have also calculated a corresponding model without rotation. The evolution has been followed up to the pre-supernova stage. Results. We find that Z = 0 models rotate with an internal profile (r) close to local angular momentum conservation, because of a very weak core-envelope coupling. Rotational mixing drives a H-shell boost due to a sudden onset of CNO cycle in the shell. This boost leads to a high 14 N production, which can be as much as 10 6 times higher than the production of the non-rotating models. Generally, the rotating models produce much more metals than their non-rotating counterparts. The mass loss is very low, even for the models that reach the critical velocity during the main s equence. It may however have an impact on the chemical enrichment of the Universe, because some of the stars are supposed to collapse directly into black holes. They would contribute to the enrichment only through their winds. While in that case non-rotating st ars would not contribute at all, rotating stars may leave an i mprint in their surrounding. Due to the low mass loss and the weak coupling, the core retains a high angular momentum at the end of the evolution. The high rotation rate at death probably leads to a much stronger explosion than previously expected, changing the fate of the models. The inclusion of our yields in a chemical evolution model of the Galactic halo predicts log values of N/O, C/O and 12 C/ 13 C ratios of -2.2, -0.95 and 50 respectively at log O/H +12 = 4.2.

Subfields: Astronomy and Astrophysics, Electrical and Electronic Engineering, Instrumentation

View Paper: https://www.semanticscholar.org/paper/558264d551b082486eae70c5f5b0dc8155f1ea20

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. N. Langer
2. Selma de Mink
3. R. Hirschi
4. Robert G. Izzard
5. Stan Woosley
6. G. Meynet
7. A. Chieffi
8. M. Limongi

In Electrical and Electronic Engineering

1. A. Ferrara
2. S. Ridgway
3. A. Tokovinin
4. Timothy Morton

In Instrumentation

1. Selma de Mink
2. N. Langer
3. Robert G. Izzard
4. R. Hirschi
5. A. Chieffi
6. M. Limongi
7. G. Meynet
8. H. Sana

Citations in the corpus

• Formation of Supermassive Black Hole Seeds (2016, background): “…simulations suggest that some of the Pop III stars might be rotating at ≥ 1000 km/s, i.e. close to their break up limit (Stacy et al. 2011), stellar evolution calculations including rotation (Ekström et al. 2008) indicate that the mass loss from the fast rotating Pop III stars is still very low.”
• Quantifying the uncertainties of chemical evolution studies II. Stellar yields (2010, methodology): “It is apparent that only Models 6 to 15, adopting the N yields from low-metallicity massive stars from the Geneva group, are abl to explain the current measurements of [N/O] and [N/Fe] in very metal-poor halo stars (see also Ekström et al. 2008, their figure 9).”
• Precision big bang nucleosynthesis with improved Helium-4 predictions (2018, background): “Finally, our prediction of CNO abundance (Table VII) does not completely rule out the possibility that they may influence the evolution of some of the first, Population III, stars (Ekström et al., 2008).”
• Europium production: neutron star mergers versus core-collapse supernovae (2013, methodology): “Here we adopt He, C, N and O yields from pre-supernova models of rotating massive stars from Meynet& Maeder (2002b), Hirschi et al. (2005), Hirschi (2007) and Ekström et al. (2008).”
• CONVECTIVE–REACTIVE PROTON–12C COMBUSTION IN SAKURAI'S OBJECT (V4334 SAGITTARII) AND IMPLICATIONS FOR THE EVOLUTION AND YIELDS FROM THE FIRST GENERATIONS OF STARS (2010, background): “…2002; Campbell & Lattanzio 2008), young white dwarfs of solar metallicity (e.g. Iben et al. 1983; Herwig et al. 1999; Lawlor & MacDonald 2003), both rotating and nonrotating Pop III massive stars (Ekström et al. 2008), and more in general, in low metallicity massive stars (Woosley & Weaver 1995).”
• Evolution and fate of very massive stars (2013, background): “…for the rotating solar metallicity 150 and 500 M and SMC 150 M models as a function of age of the star. and zero metallicity stars (Hirschi 2007; Ekström et al. 2008; Chatzopoulos & Wheeler 2012; Yoon et al. 2012), mass loss eventually starts to dominate and the surface velocity and its ratio…”
• s-process production in rotating massive stars at solar and low metallicities (2015, unknown): “…a behaviour a bit similar to Pop III (metal-free) stars, which cannot produce enough energy by the pp-chains and therefore go into a state of combined hydrogen and weak He-burning, producing non-negligible amounts of primary 14N as in previous studies (Ekström et al. 2008; Heger & Woosley 2010).”
• Varying Constants, Gravitation and Cosmology (2010, background): “Besides, one would need to include rotation and mass loss [181].”
• STELLAR ABUNDANCES IN THE SOLAR NEIGHBORHOOD: THE HYPATIA CATALOG (2014, background): “…stars by the CNO cycle (Arnett 1996), where primary nitrogen is usually produced as a convective helium burning shell mixes into a hydrogen shell, where C and O nuclei form nitrogen with nearly explosive consequences (Talbot & Arnett 1974; Meynet & Maeder 2002a; Ekström et al. 2008; Karakas 2010).”
• PRE-SUPERNOVA EVOLUTION OF ROTATING SOLAR METALLICITY STARS IN THE MASS RANGE 13–120 M☉ AND THEIR EXPLOSIVE YIELDS (2012, methodology): “…stars – 4 – have been computed and discussed by Meynet & Maeder (2000, 2003); Hirschi et al. (2004); Meynet & Maeder (2005); Decressin et al. (2007); Ekström et al. (2008); Ekström et al. (2012) and Heger et al. (2000); Heger & Langer (2000); Heger et al. (2005); Yoon & Langer (2005); Yoon et…”
• THE ROTATION RATES OF MASSIVE STARS: THE ROLE OF BINARY INTERACTION THROUGH TIDES, MASS TRANSFER, AND MERGERS (2012, methodology): “We refer the reader to the excellent discussion by Ekström et al. (2008b), which describes this effect in detailed models of single stars that allow for differential rotation.”
• A CHARA ARRAY SURVEY OF CIRCUMSTELLAR DISKS AROUND NEARBY Be-TYPE STARS (2013, methodology): “The ratio of angular rotational velocities is given for the Roche approximation using expressions from Ekström et al. (2008), Ωrot Ωcrit = 3 2 Vrot Vcrit [ 1− 1 3 ( Vrot Vcrit )2 ] .”
• STANDARD BIG BANG NUCLEOSYNTHESIS UP TO CNO WITH AN IMPROVED EXTENDED NUCLEAR NETWORK (2011, background): “The minimum value of the initial CNO mass fraction that would affect Pop III stellar evolution is estimated to be 10−10 (Cassisi & Castellani 1993) or even as low as 10−12 in mass fraction for the less massive ones (Ekström et al. 2008).”