Limits on Pop III star formation with the most iron-poor stars

Abstract

We study the impact of star-forming mini-haloes, and the Initial Mass Function (IMF) of Population III (Pop III) stars, on the Galactic halo Metallicity Distribution Function (MDF) and on the properties of C-enhanced and C-normal stars at [Fe/H]<-3. For our investigation we use a data-constrained merger tree model for the Milky Way formation, which has been improved to self-consistently describe the physical processes regulating star-formation in mini-haloes, including the poor sampling of the Pop III IMF. We find that only when star-forming mini-haloes are included the low-Fe tail of the MDF is correctly reproduced, showing a plateau that is built up by C-enhanced metal-poor (CEMP) stars imprinted by primordial faint supernovae. The incomplete sampling of the Pop III IMF in inefficiently star-forming mini-haloes (< $10^{-3}$ $M_{\odot }$/yr) strongly limits the formation of Pair Instability Supernovae (PISNe), with progenitor masses $m_{\mathrm{popIII}}$=[140-260] $M_{\odot }$, even when a flat Pop III IMF is assumed. Second-generation stars formed in environments polluted at >50% level by PISNe are thus extremely rare, corresponding to $\approx$ 0.25% of the total stellar population at [Fe/H]<-2, which is consistent with recent observations. The low-Fe tail of the MDF strongly depends on the Pop III IMF shape and mass range. Given the current statistics, we find that a flat Pop III IMF model with $m_{\mathrm{popIII}}$=[10-300] $M_{\odot }$ is disfavoured by observations. We present testable predictions for Pop III stars extending down to lower masses, with $m_{\mathrm{popIII}}$=[0.1-300] $M_{\odot }$.

15 pages, 11 figures. Accepted for publication in MNRAS. The only change is the correction of a mistake in the list of authors

References in corpus (30)

• The Kinematics of the Ultra-Faint Milky Way Satellites: Solving the Missing Satellite Problem
• Nucleosynthetic signatures of the first stars
• Massloss of galaxies due to a UV-background
• Dust Formation and Survival in Supernova Ejecta
• An extremely primitive halo star
• Carbon-Enhanced Metal-Poor Star Frequencies in the Galaxy: Corrections for the Effect of Evolutionary Status on Carbon Abundances
• Primordial Star Formation under the Influence of Far Ultraviolet Radiation: 1540 Cosmological Halos and the Stellar Mass Distribution
• The Mass Spectrum of the First Stars
• Fragmentation of star-forming clouds enriched with the first dust
• Generating Dark Matter Halo Merger Trees
• HE 0557-4840 - Ultra-Metal-Poor and Carbon-Rich
• HI-to-H2 Transitions and H I Column Densities in Galaxy Star-Forming Regions
• On the Shoulders of Giants: Properties of the Stellar Halo and the Milky Way Mass Distribution
• The stellar content of the Hamburg/ESO survey. IV. Selection of candidate metal-poor stars
• TOPoS: II. On the bimodality of carbon abundance in CEMP stars. Implications on the early chemical evolution of galaxies
• Kinematics of the stellar halo and the mass distribution of the Milky Way using BHB stars
• Initial mass function of intermediate mass black hole seeds
• An Elemental Assay of Very, Extremely, and Ultra Metal-Poor Stars
• Ultra faint dwarfs: probing early cosmic star formation
• Uncovering the Chemical Signature of the First Stars in the Universe
• Constraining the primordial initial mass function with stellar archaeology
• Decoding the stellar fossils of the dusty Milky Way progenitors
• Life and times of dwarf spheroidal galaxies
• The first stars: CEMP--no stars and signatures of spinstars
• Faint Population III supernovae as the origin of the most iron-poor stars
• The first carbon-enhanced metal-poor star found in the Sculptor dwarf spheroidal
• Ultrafaint Dwarf Galaxies - the lowest mass relics from before reionization
• The origin of the most iron-poor star
• Galaxy formation with radiative and chemical feedback
• An equatorial ultra iron-poor star identified in BOSS

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• The low-end of the black hole mass function at cosmic dawn
• Light, medium-weight or heavy? The nature of the first supermassive black hole seeds
• Probing the existence of very massive first stars
• Where does galactic dust come from?
• Ultra-faint dwarf galaxies: unveiling the minimum mass of the first stars
• Zinc in the Sculptor dwarf spheroidal galaxy
• A Minimum Dilution Scenario for Supernovae and Consequences for Extremely Metal-Poor Stars
• Unveiling early black hole growth with multi-frequency gravitational wave observations
• Observational constraints on the survival of pristine stars
• Origin of the CEMP-no Group Morphology in the Milky Way
• Following the Cosmic Evolution of Pristine Gas III: The Observational Consequences of the Unknown Properties of Population III Stars
• Implications of inhomogeneous metal mixing for stellar archaeology
• Chemical Cartography. II. The Assembly History of the Galactic Stellar Halo Traced by Carbon-Enhanced Metal-Poor Stars
• Formation of carbon-enhanced metal-poor stars as a consequence of inhomogeneous metal mixing
• Neutron-capture elements in dwarf galaxies II: Challenges for the s- and i-processes at low metallicity
• Evidence of First Stars-enriched Gas in High-redshift Absorbers
• The energy distribution of the first supernovae
• Seeding the second star -- II. CEMP star formation enriched from faint supernovae
• Understanding the origin of CEMP-no stars through ultra-faint dwarfs
• PISN-explorer: hunting the descendants of very massive first stars
• Tracing stars in Milky Way satellites with A-SLOTH
• A-SLOTH: Ancient Stars and Local Observables by Tracing Halos
• On the dearth of C-enhanced metal-poor stars in the Galactic bulge