Lithium depletion in solar-like stars: effect of overshooting based on realistic multi-dimensional simulations
| Autor: | Jane Pratt, M. V. Popov, Rolf Walder, Isabelle Baraffe, T. Goffrey, T. Constantino, Doris Folini, Maxime Viallet |
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| Přispěvatelé: | Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2017 |
| Předmět: |
010504 meteorology & atmospheric sciences
Energy transfer Dirac (software) chemistry.chemical_element FOS: Physical sciences stars: pre-main sequence 7. Clean energy 01 natural sciences stars: rotation 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics stars: evolution Aerospace engineering 010303 astronomy & astrophysics convection Solar and Stellar Astrophysics (astro-ph.SR) 0105 earth and related environmental sciences Physics business.industry stars: solar-type Astronomy and Astrophysics Supercomputer Stars Astrophysics - Solar and Stellar Astrophysics chemistry [SDU]Sciences of the Universe [physics] 13. Climate action Space and Planetary Science hydrodynamics Multi dimensional Lithium business |
| Zdroj: | The Astrophysical Journal Letters The Astrophysical Journal Letters, 2017, 845, ⟨10.3847/2041-8213/aa82ff⟩ |
| DOI: | 10.48550/arxiv.1707.09498 |
| Popis: | We study lithium depletion in low-mass and solar-like stars as a function of time, using a new diffusion coefficient describing extra-mixing taking place at the bottom of a convective envelope. This new form is motivated by multi-dimensional fully compressible, time implicit hydrodynamic simulations performed with the MUSIC code. Intermittent convective mixing at the convective boundary in a star can be modeled using extreme value theory, a statistical analysis frequently used for finance, meteorology, and environmental science. In this letter, we implement this statistical diffusion coefficient in a one-dimensional stellar evolution code, using parameters calibrated from multi-dimensional hydrodynamic simulations of a young low-mass star. We propose a new scenario that can explain observations of the surface abundance of lithium in the Sun and in clusters covering a wide range of ages, from $\sim$ 50 Myr to $\sim$ 4 Gyr. Because it relies on our physical model of convective penetration, this scenario has a limited number of assumptions. It can explain the observed trend between rotation and depletion, based on a single additional assumption, namely that rotation affects the mixing efficiency at the convective boundary. We suggest the existence of a threshold in stellar rotation rate above which rotation strongly prevents the vertical penetration of plumes and below which rotation has small effects. In addition to providing a possible explanation for the long standing problem of lithium depletion in pre-main sequence and main sequence stars, the strength of our scenario is that its basic assumptions can be tested by future hydrodynamic simulations. Comment: 7 pages, 3 figures, Accepted for publication in ApJ Letters |
| Databáze: | OpenAIRE |
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