A study of the spectrum of WZ SGE during its 1978 outburst.

Abstract

High dispersion short wavelength region IUE spectra of WZ Sge were obtained by the VILSPA tracking station near Madrid in December 1978. The profiles, both absorption and emission, are classified, and their regions of formation are considered in the framework of the standard accretion disk and excretion disk models. The C IV resonance blend is shown to consist of emission components having a similar profile to that of He II 1640.4 A, and the shape of the He II profile suggests the existence of an outer disk. The apparent N V absorption line blackness, indicating no emission filling-in for this more separate doublet, suggests that gas with projected rotational velocities of 960 km/s or more came from the inner disk, much smaller than the line absorbing region. Low ionization C II and Si IV profiles, almost completely in absorption, give conditions for the particle densities of the line formation region.