Theoretical basal flux limits for stars with low metallicity
Diaa Fawzy (Astronomy Dept., Faculty of Science
Cairo University, Egypt)
Wolfgang Rammacher (Institut for Theoretical Astrophysics, Univ. Heidelberg - Germany)
Peter Ulmschneider (Institut for Theoretical Astrophysics, Univ. Heidelberg - Germany)
The minimum observed stellar MgII h+k & CaII H+K chromospheric fluxes form what is called the
basal flux line. These fluxes are referred to be originated by a non-magnetic heating mechanisms,
the dissipation of the acoustic waves is thus identified as a source of heating.
Observationally, the basal flux line is the same for the stars which have high or low metallicity.
The current work shows the first theoretical basal flux lines for stars of different
metallicity based on self consistent time- dependent chromosheric models. These models are computed
using the following three basic parameters; the effective temperature, gravity and the metallicity.