EFFECTS OF HEAVY-METALS ON ASTROPHYSICAL OPACITIES

Recent reexaminations of astrophysical opacities resulted in large opacity increases. The increases were mostly due to improvements in the atomic physics used in the calculations; in particular, the treatment of bound-bound transitions of partially ionized Fe. The new opacities were also found to depend on other Fe group elements even though in typical stars these elements have a combined abundance that is more than an order of magnitude lower than Fe. It is, therefore, important to examine the contributions from even heavier elements. These elements are much lower in abundance still, but have many more bound electrons and could, in principle, impact astrophysical opacities. It is shown that although the heavy elements are stronger photon absorbers their small abundance leads to a marginal effect on the Rosseland mean opacities of stars with solar metal distributions.