Multi-dimensional structure of accreting young stars
| Autor: | Jane Pratt, Rolf Walder, T. Goffrey, M. V. Popov, Maxime Viallet, Doris Folini, C. Geroux, Isabelle Baraffe, T. Constantino |
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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: | 2016 |
| Předmět: |
Astrophysics::High Energy Astrophysical Phenomena
Dirac (software) Library science FOS: Physical sciences Astrophysics stars: pre-main sequence Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences Accretion disc accretion 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics stars: evolution 010303 astronomy & astrophysics convection Astrophysics::Galaxy Astrophysics Solar and Stellar Astrophysics (astro-ph.SR) Physics stars: formation [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] 010308 nuclear & particles physics European research accretion disks Astronomy and Astrophysics Astrophysics - Solar and Stellar Astrophysics 13. Climate action Space and Planetary Science [SDU]Sciences of the Universe [physics] hydrodynamics Multi dimensional Astrophysics::Earth and Planetary Astrophysics |
| Zdroj: | Astronomy and Astrophysics-A&A Astronomy and Astrophysics-A&A, 2016, 588, ⟨10.1051/0004-6361/201528038⟩ |
| ISSN: | 0004-6361 |
| DOI: | 10.48550/arxiv.1602.03325 |
| Popis: | This work is the first attempt to describe the multi-dimensional structure of accreting young stars based on fully compressible time implicit multi-dimensional hydrodynamics simulations. One major motivation is to analyse the validity of accretion treatment used in previous 1D stellar evolution studies. We analyse the effect of accretion on the structure of a realistic stellar model of the young Sun. Our work is inspired by the numerical work of Kley \& Lin (1996, ApJ, 461, 933) devoted to the structure of the boundary layer in accretion disks. We analyse the redistribution of accreted material with a range of values of specific entropy relative to the bulk specific entropy of the material in the accreting object's convective envelope. A primary goal is to understand whether and how accreted energy deposited onto a stellar surface is redistributed in the interior. This study focusses on the high accretion rates characteristic of FU Ori systems. We find that the highest entropy cases produce a distinctive behaviour in the mass redistribution, rms velocities, and enthalpy flux in the convective envelope. This change in behaviour is characterised by the formation of a hot layer on the surface of the accreting object, which tends to suppress convection in the envelope. We analyse the long-term effect of such a hot buffer zone on the structure and evolution of the accreting object with 1D stellar evolution calculations. We study the relevance of the assumption of redistribution of accreted energy into the stellar interior used in the literature. One conclusion is that, for a given amount of accreted energy transferred to the accreting object, a treatment assuming accretion energy redistribution throughout the stellar interior could significantly overestimate the effects on the stellar structure, in particular, on the resulting expansion. 11 pages, 11 figures, accepted for publication in A&A |
| Databáze: | OpenAIRE |
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