Simulations of Core Convection in Rotating A-Type Stars: Differential Rotation and Overshooting
By M. Browning, A. Brun, J. Toomre. 2003
137 citations recorded by the source corpus.
We present the results of three-dimensional simulations of core convection within A-type stars of 2 M☉, at a range of rotation rates. We consider the inner 30% by radius of such stars, thereby encompassing the convective core and some of the surrounding radiative envelope. We utilize our anelastic spherical harmonic code, which solves the compressible Navier-Stokes equations in the anelastic approximation, to examine highly nonlinear flows that can span multiple scale heights. The cores of these stars are found to rotate differentially, with central cylindrical regions of strikingly slow rotation achieved in our simulations of stars whose convective Rossby number (Roc) is less than unity. Such differential rotation results from the redistribution of angular momentum by the nonlinear convection that strongly senses the overall rotation of the star. Penetrative convective motions extend into the overlying radiative zone, yielding a prolate shape (aligned with the rotation axis) to the central region in which nearly adiabatic stratification is achieved. This is further surrounded by a region of overshooting motions, the extent of which is greater at the equator than at the poles, yielding an overall spherical shape to the domain experiencing at least some convective mixing. We assess the overshooting achieved as the stability of the radiative exterior is varied and the weak circulations that result in that exterior. The convective plumes serve to excite gravity waves in the radiative envelope, ranging from localized ripples of many scales to some remarkable global resonances.
Subfields: Astronomy and Astrophysics
View Paper: https://www.semanticscholar.org/paper/44ce88afd928ddfe138dfddc23ae5992ee3d3550
How researchers see this paper
The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.
In Astronomy and Astrophysics
Citations in the corpus
- Rotational mixing in low-mass stars: II. Self-consistent models of Pop II RGB stars (2006, background): “The interaction between rotation and convection is a longstanding and not fully understood problem, and despite the development of 3D numerical simulations (Ballot et al. 2004; Browning et al. 2004), the rotation profile within deep convective envelopes remains unknown.”
- Magnetic Field Generation in Fully Convective Rotating Spheres (2004, methodology): “Meanwhile, such global models have also been applied to core convection (Browning et al. 2004) and to dynamo action in these cases (Brun et al. 2005).”
- Transport and mixing in the radiation zones of rotating stars. I. Hydrodynamical processes (2004, methodology): “…the rotation rateΩ(r, θ) seems to be independent ofr in the solar convection zone, we can take ∂rΩ(r) = 0 atr = rt, ∂rΩl(r) = 0 at r = rt. (107) For the condition at the boundary of a convective core, we will have to rely on numerical simulations (see the recent results of Browning et al. 2004).”
- Simulations of Dynamo Action in Fully Convective Stars (2007, background): “The analogy in 13 deeper spherical domains appears to be the acceleration of columns of fluid that lie far from the rotation axis, as realized here and in the core convection simulations of Browning et al. (2004).”