Very Massive Close Binaries and the Puzzling Temporal Evolution of 14N in the Solar Neighbourhood

Abstract

Low metallicity very massive stars with an initial mass between 140 Mo and 260 Mo can be subdivided into two groups: those between 140 Mo and 200 Mo which produce a relatively small amount of Fe, and those with a mass between 200 Mo and 260 Mo where the Fe-yield ejected during the supernova explosion is enormous. We first demonstrate that the inclusion of the second group into a chemical evolutionary model for the Solar Neighbourhood predicts an early temporal evolution of Fe which is at variance with observations whereas it can not be excluded that the first group could have been present. We then show that a low metallicity binary with very massive components (with a mass corresponding to the first group) can be an efficient site of primary 14N production through the explosion of a binary component that has been polluted by the pair instability supernova ejecta of its companion. When we implement these massive binary 14N yields in a chemical evolution model, we conclude that very massive close binaries may be important sites of 14N enrichment during the early evolution of the Galaxy.

arXiv comment15 pages, 9 figures, accepted for New Astronomy

References in corpus (32)

• Embedded Clusters in Molecular Clouds
• The Nucleosynthetic Signature of Population III
• The Formation of the First Star in the Universe
• Dynamo action by differential rotation in a stably stratified stellar interior
• The First Stars
• The Chemical Evolution of the Galaxy: the two-infall model
• Wilkinson Microwave Anisotropy Probe (WMAP) First Year Observations: TE Polarization
• The Formation of a Star Cluster: Predicting the Properties of Stars and Brown Dwarfs
• The runaway growth of intermediate-mass black holes in dense star clusters
• Stellar evolution with rotation VIII: Models at Z = 10^{-5} and CNO yields for early galactic evolution
• On the Formation of Massive Stars
• Pair-Instability Supernovae, Gravity Waves, and Gamma-Ray Transients
• On the formation of massive stars
• First stars VI - Abundances of C, N, O, Li, and mixing in extremely metal-poor giants. Galactic evolution of the light elements
• The hierarchical formation of a stellar cluster
• A Wide Symbiotic Channel to Type Ia Supernovae
• Neutron star mergers versus core-collapse supernovae as dominant r-process sites in the early Galaxy
• The Formation of Stellar Clusters: Gaussian Cloud Conditions I
• Zero-metallicity stars I. Evolution at constant mass
• The Birth of High Mass Stars: Accretion and/or Mergers?
• A strong case for fast stellar rotation at very low metallicities
• The evolution of the C/O ratio in metal-poor halo stars
• Cosmic Reionisation by Stellar Sources: Population II Stars
• Stellar evolution with rotation and magnetic fields II: General equations for the transport by Tayler--Spruit dynamo
• Galactic Evolution of Nitrogen
• The Origin of Massive O-type Field Stars. Part I: A Search for Clusters
• Zero-metallicity stars II. Evolution of very massive objects with mass loss
• The origin of nitrogen: Implications of recent measurements of N/O in Galactic metal-poor stars
• The influence of binaries on galactic chemical evolution
• The effects of Population III stars and variable IMF on the chemical evolution of the Galaxy
• The chemical evolution of the Galaxy: the importance of stars with an initial mass larger than 40Mo
• The early phases of Milky Way's chemical evolution