The equilibrium structure of a thin magnetic flux tube. III - The effects of molecular CO absorption

The authors determine the structure of a stellar atmosphere and of a thin magnetic flux tube embedded in it, taking the opacity by H- and carbon monoxide into account. It is found that CO has a strong cooling effect on the external atmosphere. For effective temperatures below ≡5900K, the surface temperature of the atmosphere with H- and CO opacity is much lower than with H- alone. In the interior of the flux tube the equations can have multiple solutions. Thus hot flux tubes can exist in a cool atmosphere even in the absence of nonradiative heating.