Effect of interstellar objects on metallicity of low-mass first stars formed in a cosmological model

Abstract

We investigate metal pollution onto the surface of low-mass population III stars (Pop. III survivors) via interstellar objects floating in the Galactic interstellar medium. Only recently, Tanikawa et al. analytically estimated how much metal should collide to an orbiting Pop. III survivor encouraged by the recent discovery of 'Oumuamua and suggested that ISOs are the most dominant contributor of metal enrichment of Pop. III survivors. When we consider a distribution of interstellar objects in the Galactic disc, Pop. III survivors' orbits are significant properties to estimate the accretion rate of them though Tanikawa et al. assumed one modelled orbit. To take more realistic orbits into calculating the accretion rate, we use a high-resolution cosmological $N$-body simulation that resolves dark matter minihaloes. Pop. III survivors located at solar neighbourhood have a number of chances of ISO($>100$ m) collisions, typically $5\times 10^6$ times in the last $5$ Gyr, which is one order of magnitude greater than estimated in the previous study. When we assume a power-law parameter $\alpha$ of the ISO cumulative number density with size greater than $D$ as $n\propto D^{-\alpha }$, $0.80M_{\odot }$ stars should be typically polluted [Fe/H]$\sim -2$ for the case of $\alpha =2.0$. Even in the cases of $0.70$ and $0.75M_{\odot }$ stars, the typical surface metallicity are around [Fe/H]$=-6\sim -5$. From the presence of stars with their [Fe/H], we can constrain on the lower limit of the power $\alpha$, as $\alpha \gtrsim 2.0$, which is consistent with $\alpha$ of km-size asteroids and comets in the solar system. Furthermore, we provide six candidates as the ISO-polluted Pop. III stars in the case of $\alpha \sim 2.5$. Metal-poor stars so far discovered are possible to be metal-free Pop. III stars on birth.

arXiv comment8 pages, 3 figures, Accepted for publication in MNRAS

References in corpus (55)

• The chemical composition of the Sun
• Gaia Data Release 2. Summary of the contents and survey properties
• Planck 2013 results. XVI. Cosmological parameters
• The Rockstar Phase-Space Temporal Halo Finder and the Velocity Offsets of Cluster Cores
• The Formation of the First Star in the Universe
• The Formation of the First Stars. I. The Primordial Star Forming Cloud
• How small were the first cosmological objects?
• Gravitationally Consistent Halo Catalogs and Merger Trees for Precision Cosmology
• Density of asteroids
• One Hundred First Stars : Protostellar Evolution and the Final Masses
• Possible interaction between baryons and dark-matter particles revealed by the first stars
• Near-Field Cosmology with Metal-Poor Stars
• First stars, very massive black holes and metals
• Formation of Primordial Stars in a LCDM Universe
• Simulations on a Moving Mesh: The Clustered Formation of Population III Protostars
• The Stellar Abundances for Galactic Archeology (SAGA) Database - Compilation of the Characteristics of Known Extremely Metal-Poor Stars
• The Formation and Fragmentation of Disks around Primordial Protostars
• Protostellar Feedback Halts the Growth of the First Stars in the Universe
• Protostar Formation in the Early Universe
• The formation of the first stars and galaxies
• Formation of the First Stars by Accretion
• On the Initial Mass Function of Population III Stars
• 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
• Formation of Primordial Protostars
• Gravitational fragmentation in turbulent primordial gas and the initial mass function of Population III stars
• The Origin of Disks and Spheroids in Simulated Galaxies
• Solar System Abundances of the Elements
• The First Stars: Mass Growth Under Protostellar Feedback
• The Size Distribution of Kuiper Belt Objects
• Formation Scenario for Wide and Close Binary Systems
• Spectroscopy and thermal modelling of the first interstellar object 1I/2017 U1 'Oumuamua
• Could Solar Radiation Pressure Explain 'Oumuamua's Peculiar Acceleration?
• Interstellar Interlopers: Number Density and Origins of 'Oumuamua-like Objects
• GreeM : Massively Parallel TreePM Code for Large Cosmological N-body Simulations
• Tracing the formation of the Milky Way through ultra metal-poor stars
• Constraining the primordial initial mass function with stellar archaeology
• Models of Metal Poor Stars with Gravitational Settling and Radiative Accelerations: I. Evolution and Abundance Anomalies
• The origin of interstellar asteroidal objects like 1I/2017 U1 'Oumuamua
• Where are the Low-Mass Population III Stars ?
• The Feasibility and Benefits of In Situ Exploration of `Oumuamua-like objects
• Predicting the locations of possible long-lived low-mass first stars: Importance of satellite dwarf galaxies
• The ${\nu }^2$GC Simulations : Quantifying the Dark Side of the Universe in the Planck Cosmology
• The Composition of M-type asteroids II: Synthesis of spectroscopic and radar observations
• Tracing the first stars and galaxies of the Milky Way
• Interstellar object 'Oumuamua as an extinct fragment of an ejected cometary planetesimal
• Magnitude and size distribution of long-period comets in Earth-crossing or approaching orbits
• Rotation Curve Decomposition for Size-Mass Relations of Bulge, Disk, and Dark Halo in Spiral Galaxies
• Stellar Winds and Coronae of Low-mass Pop. II/III Stars
• Observational constraints on the survival of pristine stars
• 1I/2017 'Oumuamua-like Interstellar Asteroids as Possible Messengers from the Dead Stars
• The most iron-deficient stars as the polluted population III stars
• Blocking metal accretion onto population III stars by stellar wind
• Chemical enrichment of stars due to accretion from ISM during the Galaxy's assembly
• Metal Pollution of Low-Mass Population III Stars through Accretion of Interstellar Objects like `Oumuamua

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• Potential signature of Population III pair-instability supernova ejecta in the BLR gas of the most distant quasar at z = 7.54
• Modeling the survival of Population III stars till present day
• Simulating the collapse of rotating primordial gas clouds to study the survival possibility of Pop III protostars
• Studying The Effect of Radiation Pressure on Evolution of a Population III Stellar Cluster