Improvements to stellar structure models, based on a grid of 3D convection simulations. II. Calibrating the mixing-length formulation

By R. Trampedach, Robert F. Stein, J. Christensen-Dalsgaard, Åke Nordlund, Martin Asplund. 2014

133 citations recorded by the source corpus.

ABSTRACT Weperformacalibrationofthemixinglengthofconvectioninstellarstructuremodelsagainstrealistic3Dradiation-coupledhydrodynamics(RHD)simulationsofconvectioninstellarsurfacelayers,determiningtheadiabatdeepinconvectivestellarenvelopes.The mixing-length parameter α is calibrated by matching averages of the3Dsimulationsto1Dstellarenvelopemodels,ensuringidenticalatomicphysicsinthetwocases.Thisisdoneforapreviouslypublishedgridofsolar-metallicityconvectionsimulations,coveringfrom4200Kto6900Konthemainsequence,and4300–5000Kforgiantswithlogg =2.2.Ourcalibrationresultsinanα varyingfrom1.6forthewarmestdwarf,whichisjustcoolenoughtoadmitaconvectiveenvelope,andupto2.05forthecoolestdwarfsinourgrid.Inbetweentheseisatriangularplateauofα ∼1.76.TheSunislocatedonthisplateauandhasseenlittlechangeduringitsevolutionsofar.Whenstarsascendthegiantbranch,theylargelydosoalongtracksofconstantα,withα decreasingwithincreasingmass.Key words: Stars:atmospheres–stars:evolution–convection 1 INTRODUCTIONDue to the lack of a better theory of convection in stars,the mixing-length theory (B¨ohm-Vitense 1958, MLT) hasbeen in use for more thanhalf a century.By far the largestpart of the solar convection zone is very close to adia-batic, and the stratification in the bulk of the convectionzone is therefore determined by the adiabatic gradient,∇

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/48aaff5b5feb459e30e23288fc2707a7371fd070

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

1. D. Huber
2. D. Stello
3. Aaron Dotter
4. C. Conroy
5. W. Chaplin
6. A. Serenelli
7. T. Bedding
8. A. Miglio

Citations in the corpus

• The Updated BaSTI Stellar Evolution Models and Isochrones. I. Solar-scaled Calculations (2018, methodology): “…(1) As shown by Salaris & Cassisi (2015), model tracks computed with this T (τ) relation approximate well results obtained using the hydro-calibrated T (τ) relationships determined from the 3D radiation hydrodynamics calculations by Trampedach et al. (2014) for the solar chemical composition.”
• MESA ISOCHRONES AND STELLAR TRACKS (MIST). I. SOLAR-SCALED MODELS (2016, background): “…all masses, evolutionary phases, and abundances, there has been a recent effort to map out αMLT as a function of logg and Teff (Trampedach 2007; Trampedach et al. 2014) as well as metallicity (Magic et al. 2015) from full 3D radiative hydrodynamic calculations of convection in stellar…”
• Standing on the Shoulders of Dwarfs: the Kepler Asteroseismic LEGACY Sample. II. Radii, Masses, and Ages (2016, methodology): “…in the outer stellar layers without the need of free parameters, and can be used to calibrate the expected mixing-length parameter by matching a 1D envelope model to a suitable average of the 3D simulations (see Trampedach et al. 2014; Magic et al. 2015, for a description of the procedure).”
• Ages and fundamental properties of Kepler exoplanet host stars from asteroseismology (2015, methodology): “Similarly, these simulations predict variations in the efficiency of convection as a function of Teff and [Fe/H] (e.g., Trampedach et al. 2014; Magic, Weiss & Asplund 2014).”