Cairo University

MTPR Journal



K. Werner
Astronomy and Astrophysics, University of Tuebingen, Germany
Vol./Issue: 16 , id: 181

Atomic data for highly ionized species beyond the iron group are scarce. We have discovered hot white dwarf stars exhibiting spectral lines of this species, originating from atmospheric plasmas with temperatures of the order 100,000 Kelvin. Ultraviolet spectroscopy is executed with the Hubble Space Telescope. We perform quantummechanical calculations to obtain line-transition probabilities and level-excitation energies. The data are validated by feeding them into stellar atmosphere models to compute stellar spectra which are then compared to the observations. In this way, we were using stars to obtain, for the first time ever, atomic data of many heavy elements like Zn, Ga, Ge, Kr, Zr, Mo, Xe, and Ba in ionization stages IV-VII.