Analysis of the ultraviolet spectrum (2000 A to 3000 A) of Vega.

Abstract

A high-dispersion spectrum of Vega between 2000 and 3000 A is analyzed. The continuum level is determined by searching for line-free windows, comparing the observed spectrum with a synthesized one. The damping constant of the Fe II lines arising from low-excitation levels is found to be very close to the classical value. The microturbulence parameter deduced from the UV Fe II lines is 2.0 + or - 0.5 km/s and coincides with the value obtained in the visual region. The abundances of five iron peak elements (Cr through Ni) obtained from the UV lines are found to agree with those obtained in the visual region. The deficiency of iron in the atmosphere of Vega is reconfirmed.