A Far-Ultraviolet Study of the Hot White Dwarf in the Dwarf Nova WW Ceti

Abstract

We present a synthetic spectral analysis of IUE archival and FUSE (Far Ultraviolet Spectroscopic Explorer) far-UV spectra of the peculiar dwarf nova WW Cet. During the quiescence of WW Cet, a white dwarf with T wd ∼ 26,000 ± 1000 K can account for the far-UV flux and yields the proper distance. However, the best agreement with the observations is provided by a two-temperature white dwarf model with a cooler white dwarf at T wd = 25,000 K providing 75% of the far-UV flux and a hotter region (accretion belt or optically thick disk ring) with T = 40,000 K contributing 25% of the flux for the proper distance. We find from the FUSE spectrum that the white dwarf is rotating with V sin i = 600 ± 100 km s -1. Our temperature results provide an additional data point in the distribution of WD T wd versus orbital period above the CV period gap, where few WD T wd values are available. © 2006. The American Astronomical Society. All rights reserved.