Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-07-05
Astronomy and Astrophysics
Astrophysics
7 pages, 6 figures, Astronomy & Astrophysics in press
Scientific paper
10.1051/0004-6361:200810253
The mixing length theory (MLT) used to compute the temperature gradient in superadiabatic layers of stellar (interior and atmosphere) models contains in its standard form 4 free parameters. Three parameters are fixed a priori (and define what we denote as the MLT 'flavour') whereas one (the so-called mixing length) is calibrated by reproducing observational constraints. The 'classical' B\"ohm-Vitense flavour is used in all modern MLT-based stellar model computations and, despite its crude approximations, the resulting $T_{eff}$ scale appears -- perhaps surprisingly -- remarkably realistic, once the mixing length parameter is calibrated with a solar model. Model atmosphere computations employ parameter choices different from what is used in stellar interior modelling, raising the question of whether a single MLT flavour and mixing length value can be used to compute interiors and atmospheres of stars of all types. As a first step towards addressing this issue, we study whether the MLT flavour (the so-called ML2) and mixing length choice that have been proven adequate to model white dwarf atmospheres, is able to provide, when used in stellar models, results at least comparable to the use of the 'classical' B\"ohm-Vitense flavour. We have computed solar models and evolutionary tracks for both low- and intermediate-mass Population I and II stars, adopting both solar calibrated B\"ohm-Vitense and ML2 flavours of the MLT in our stellar evolution code, and state-of-the-art input physics. The two sets of models provide consistent results, with only minor differences. Both calibrations reproduce also the $T_{eff}$ of red giants in a sample of Galactic globular clusters.
Cassisi Santi
Salaris Maurizio
No associations
LandOfFree
Stellar models with the ML2 theory of convection does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Stellar models with the ML2 theory of convection, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stellar models with the ML2 theory of convection will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-448748