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Stellar Archaeology as a Time Machine to the First Stars

3–7 Dec 2018
Kavli IPMU
Asia/Tokyo timezone

inquiry

Session

EMP Stars: Theory

5 Dec 2018, 11:30
Lecture Hall (Kavli IPMU)

Lecture Hall

Kavli IPMU

5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 227-8583

Presentation materials

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  1. 42. The first matter cycle in the Universe: from Population III to extremely metal-poor stars
    Gen Chiaki (Georgia Tech)
    05/12/2018, 11:30
    EMP stars

    We investigate the formation of extremely metal-poor (EMP) stars that are observed in the Galactic halo and neighboring ultra-faint dwarf galaxies. Their low metal abundances (${\rm [Fe/H]} < -3$) indicate that their parent clouds were enriched by a single or several supernovae (SNe) from the first (Pop III) stars. In this study, we perform numerical simulations of the formation sequence of a...

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  2. 75. DWARF GALAXIES - NOW AND THEN
    Dr Stefania Salvadori (University of Florence - Department of Physics and Astronomy)
    05/12/2018, 12:00
    Dwarf galaxies & Galactic chemical evolution

    Dwarf galaxies were the most common type of systems in the Early Universe. The first stars were likely hosted by dwarf galaxies, which might have provided the bulk of ionizing photons driving the early phases of reionization. In the Local Group, metal-poor dwarf galaxies hosting 13 billion years old stars are extremely common. What can we learn from detailed observations of stars in these...

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  3. 4. Metal pollution of low-mass Population III stars through accretion of interstellar objects
    Dr Ataru Tanikawa (The University of Tokyo)
    05/12/2018, 12:30
    EMP stars

    We calculate accretion mass of interstellar objects (ISOs) like Oumuamua onto low-mass population III stars (Pop. III survivors), and estimate surface pollution of Pop. III survivors. An ISO number density estimated from the discovery ofOumuamua is so high ($\sim 0.2$ au$^{-3}$) that Pop.~III survivors have chances at colliding with ISOs about $10^5$ times per $1$~Gyr. `Oumuamua itself...

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  4. 44. Chemical enrichment and stellar population age
    Yuta Tarumi
    05/12/2018, 12:50
    Poster

    The supernovae of first stars produce metals that change the star formation mode in the early Universe from a top-heavy to the present-day IMF. However, the efficiency and governing processes of metal mixing are still unknown. By analysing cosmological simulation of the first galaxies, we find a strong correlation between metal mixing efficiency and time from star formation, whereas the total...

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  5. 34. The impact of metal depletion on convective mixing prescriptions in 1D stellar evolution models
    Dr Meridith Joyce (Australian National University)
    05/12/2018, 13:00
    EMP stars

    1D stellar structure and evolution codes (SSECs) are widely used in astrophysics to determine fundamental stellar properties. Since our theoretical knowledge is incomplete, it is necessary to calibrate these codes empirically, especially free parameters such as the convective mixing length, or $\alpha_{\text{MLT}}$. Historically, we have relied on the Sun for this task. This has resulted in...

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