Did Very Massive Stars Pre-enrich and Reionize the Universe?

Abstract

Recent studies of heavy r-process elements in low [Fe/H] halo stars have suggested that an initial population of metal-free very massive stars (VMSs) may be required to provide early Fe enrichment without coproducing heavy r nuclei. We find similar abundance trends in alpha-elements (which should be copiously produced by VMSs), but not in other elements such as carbon (which should not), in agreement with this hypothesis. We then combine the corresponding level of prompt initial enrichment with models of VMS nucleosynthetic yields and spectra to estimate the corresponding ionizing fluxes. The result suggests that there may have been enough VMS activity to reionize the universe. The unusually hard spectrum of VMSs would imply a different reionization history from canonical models. HeII could have been reionized at high redshift, only to recombine as a subsequent generation of stars formed with a ``normal'' initial mass function.

4 pages, to appear in ApJ Letters

References in corpus (4)

• Massive Black Holes as Population III Remnants
• Resolving the Structure of Ionized Helium in the Intergalactic Medium with the Far Ultraviolet Spectroscopic Explorer
• Oxygen in the Very Early Galaxy
• A Model for Abundances in Metal-Poor Stars

Cited by in corpus (53)

• The First Stars
• First stars, very massive black holes and metals
• The Universe Was Reionized Twice
• Early reionization by miniquasars
• Reionization of Hydrogen and Helium by Early Stars and Quasars
• VLT/UVES Abundances in Four Nearby Dwarf Spheroidal Galaxies: II. Implications for Understanding Galaxy Evolution
• Three Epochs of Star Formation in the High Redshift Universe
• The Detectability of the First Stars and Their Cluster Enrichment Signatures
• The Contribution of the First Stars to the Cosmic Infrared Background
• Cosmic Reionisation by Stellar Sources: Population III Stars
• Was the Universe Reionized by Massive Population-III Stars?
• Dust Formation in Very Massive Primordial Supernovae
• Implications of WMAP Observations On the Population III Star Formation Processes
• The Detectability of Pair-Production Supernovae at z < 6
• The Era of Massive Population III Stars: Cosmological Implications and Self-Termination
• Deep Hubble Space Telescope Imaging of IC 1613 II. The Star Formation History
• Early Structure Formation and Reionization in a Warm Dark Matter Cosmology
• Effects of a Soft X-ray Background on Structure Formation at High Redshift
• Redshifted 21 cm Emission From the Pre-Reionization Era I. Mean Signal and Linear Fluctuations
• Nucleosynthesis, Reionization, and the Mass Function of the First Stars
• Stellar Archaeology: a Keck Pilot Program on Extremely Metal-Poor Stars from the Hamburg/ESO Survey. II. Abundance Analysis
• Population III and the Near-Infrared Background Excess
• Determination of Nucleosynthetic Yields of Supernovae and Very Massive Stars from Abundances in Metal-Poor Stars
• Zero-metallicity stars II. Evolution of very massive objects with mass loss
• From First Stars to the Spite Plateau: a Possible Reconciliation of Halo Stars Observations with Predictions from Big Bang Nucleosynthesis
• Early Structure Formation and Reionization in a Cosmological Model with a Running Primordial Power Spectrum
• Cosmic Star Formation, Reionization, and Constraints on Global Chemical Evolution
• The Heavy Element Enrichment of Lyman alpha Clouds in the Virgo Supercluster
• Probing the Dark Ages with Metal Absorption Lines
• The Extended Starformation History of the First Generation of Stars, and the Reionization of Cosmic Hydrogen
• Photo-heating and the fate of hard photons during the reionisation of HeII by quasars
• Sunyaev-Zeldovich Fluctuations from the First Stars?
• Early structure formation in quintessence models and its implications for cosmic reionisation from first stars
• Lower Metal Enrichment of Virialized Gas in Minihalos
• Observable Properties of Cosmological Reionization Sources
• The Number and Observability of Population III Supernovae at High Redshifts
• The most metal-poor damped Ly alpha system at z<3: constraints on early nucleosynthesis
• Lyman Break Galaxies and the Reionization of the Intergalactic Medium
• Ultraviolet Line Emission from Metals in the Low-Redshift Intergalactic Medium
• Did Massive Primordial Stars Preenrich the Lyman Alpha Forest?
• Early Preheating and Galaxy Formation
• The Prompt Inventory from Very Massive Stars and Elemental Abundances in Ly Alpha Systems
• Cosmic Renaissance: The First Sources of Light
• Transition From Population III to Population II Stars
• Detection and Fundamental Applications of Individual First Galaxies
• Sources for Metals in the Intergalactic Medium
• Probing reionization using quasar near-zones at redshift z ~ 6
• Lyman Break Galaxies and Reionization of the Universe
• Hierarchical Structure Formation and Chemical Evolution of Damped Ly alpha Systems
• Metal Enrichment of the Intergalactic Medium and Production of Massive Black Holes
• Morphology of the Secondary CMB Anisotropies: the Key to "Smoldering" Reionization
• Exploring the cosmic dark ages with the next generation of space and ground-based facilities
• Formation and early evolution of massive black holes