Excavation of the first stars

Abstract

The external pollution of the first stars in the Galaxy is investigated. The first stars were born in clouds composed of the pristine gas without heavy elements. These stars accreted gas polluted with heavy elements while they still remained in the cloud. As a result, it is found that they exhibit a distribution with respect to the surface metallicity. We have derived the actual form of this distribution function. This metallicity distribution function strongly suggests that the recently discovered most metal-deficient star HE0107-5240 with [Fe/H]=-5.3 was born as a metal-free star and accreted gas polluted with heavy elements. Thus the heavy elements such as Fe in HE0107-5240 must have been supplied from supernovae of later generations exploding inside the cloud in which the star had been formed. The elemental abundance pattern on the surface of stars suffering from such an external pollution should not be diverse but exhibit the average pattern of numerous supernovae. Future observations for a number of metal-deficient stars with [Fe/H]<-5 will be able to prove or disprove this external pollution scenario. Other possibilities to produce a star with this metallicity are also discussed.

4 pages, 5 figures, to appear in The Astrophysical Journal Letters

References in corpus (5)

• A stellar relic from the early Milky Way
• Observed and Physical Properties of Core-Collapse Supernovae
• Peculiar, Low Luminosity Type II Supernovae: Low Energy Explosions in Massive Progenitors?
• Chemical Composition of the Carbon-rich, Extremely Metal-Poor Star CS 29498--043: A New Class of Extremely Metal-Poor Stars with Excesses of Magnesium and Silicon
• Relics of subluminous supernovae in metal-poor stars

Cited by in corpus (31)

• Nucleosynthetic signatures of the first stars
• Variations in the Abundance Pattern of Extremely Metal-poor Stars and Nucleosynthesis in Population III Supernovae
• Evolution of Dust in Primordial Supernova Remnants: Can Dust Grains Formed in the Ejecta Survive and be Injected into the Early Interstellar Medium?
• Effects of rotation on the evolution of primordial stars
• HE0107-5240, A Chemically Ancient Star.I. A Detailed Abundance Analysis
• HE1327-2326, an unevolved star with [Fe/H]<-5.0. I. A Comprehensive Abundance Analysis
• Is HE0107-5240 A Primordial Star? -- The Characteristics of Extremely Metal-Poor Carbon-Rich Stars --
• Stellar Archaeology -- Exploring the Universe with Metal-Poor Stars
• The Origin of Carbon-Enhancement and Initial Mass Function of Extremely Metal-Poor Stars in the Galactic Halo
• The chemical compositions of the extreme halo stars HE0107-5240 and HE1327-2326 inferred from 3D hydrodynamical model atmospheres
• Where are the Low-Mass Population III Stars ?
• Chemical Abundance Analysis of the Extremely Metal-Poor Star HE 1300+0157
• On the oxygen abundance of HE0107-5240
• Metal-Poor Stars and the Chemical Enrichment of the Universe
• Galactic Chemical Evolution
• The mass spectrum of metal-free Stars resulting from photodissociation feedback: A scenario for the formation of low-mass population III stars
• The winds of the hot massive first stars
• Stochastic chemical enrichment in metal-poor systems II. Abundance ratios and scatter
• The first galaxies: simulating their feedback-regulated assembly
• The origins of light and heavy r-process elements identified by chemical tagging of metal-poor stars
• The most iron-deficient stars as the polluted population III stars
• Stellar winds and metal enrichment from fast-rotating Population III stars
• Self-enrichment of Galactic halo globular clusters: stimulated star formation and consequences for the halo metallicity distribution
• Are Faint Supernovae Responsible for Carbon-Enhanced Metal-Poor Stars?
• Population III stars around the Milky Way
• Possible Evidence for Metal Accretion onto the Surfaces of Metal-Poor Main-Sequence Stars
• Relics of metal-free low mass stars exploding as thermonuclear supernovae
• Weak wind effects in CNO driven winds of hot first stars
• Low-temperature primordial gas in merging halos
• Exploring the Universe with Metal-Poor Stars
• Telling the tale of the first stars