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Title: On the Chemical Mixing Induced by Internal Gravity Waves

Abstract

Detailed modeling of stellar evolution requires a better understanding of the (magneto)hydrodynamic processes that mix chemical elements and transport angular momentum. Understanding these processes is crucial if we are to accurately interpret observations of chemical abundance anomalies, surface rotation measurements, and asteroseismic data. Here, we use two-dimensional hydrodynamic simulations of the generation and propagation of internal gravity waves in an intermediate-mass star to measure the chemical mixing induced by these waves. We show that such mixing can generally be treated as a diffusive process. We then show that the local diffusion coefficient does not depend on the local fluid velocity, but rather on the wave amplitude. We then use these findings to provide a simple parameterization for this diffusion, which can be incorporated into stellar evolution codes and tested against observations.

Authors:
 [1];  [2]
  1. School of Mathematics, Statistics and Physics, Newcastle University, Newcastle upon Tyne (United Kingdom)
  2. Planetary Science Institute, Tucson, AZ 85721 (United States)
Publication Date:
OSTI Identifier:
22654376
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 848; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABUNDANCE; AMPLITUDES; ANGULAR MOMENTUM; DIFFUSION; GRAVITATION; GRAVITY WAVES; MAGNETOHYDRODYNAMICS; MASS; ROTATION; SIMULATION; STAR EVOLUTION; STARS; SURFACES; TWO-DIMENSIONAL CALCULATIONS

Citation Formats

Rogers, T. M., and McElwaine, J. N. On the Chemical Mixing Induced by Internal Gravity Waves. United States: N. p., 2017. Web. doi:10.3847/2041-8213/AA8D13.
Rogers, T. M., & McElwaine, J. N. On the Chemical Mixing Induced by Internal Gravity Waves. United States. doi:10.3847/2041-8213/AA8D13.
Rogers, T. M., and McElwaine, J. N. 2017. "On the Chemical Mixing Induced by Internal Gravity Waves". United States. doi:10.3847/2041-8213/AA8D13.
@article{osti_22654376,
title = {On the Chemical Mixing Induced by Internal Gravity Waves},
author = {Rogers, T. M. and McElwaine, J. N.},
abstractNote = {Detailed modeling of stellar evolution requires a better understanding of the (magneto)hydrodynamic processes that mix chemical elements and transport angular momentum. Understanding these processes is crucial if we are to accurately interpret observations of chemical abundance anomalies, surface rotation measurements, and asteroseismic data. Here, we use two-dimensional hydrodynamic simulations of the generation and propagation of internal gravity waves in an intermediate-mass star to measure the chemical mixing induced by these waves. We show that such mixing can generally be treated as a diffusive process. We then show that the local diffusion coefficient does not depend on the local fluid velocity, but rather on the wave amplitude. We then use these findings to provide a simple parameterization for this diffusion, which can be incorporated into stellar evolution codes and tested against observations.},
doi = {10.3847/2041-8213/AA8D13},
journal = {Astrophysical Journal Letters},
number = 1,
volume = 848,
place = {United States},
year = 2017,
month =
}