FUSE Observations of the Dwarf Novae UU Aql , BV Cen , and CH UMa in Quiescence

We report on FUSE spectra of three U Gem-type, long period, dwarf novae, UU Aql, BV Cen and CH UMa taken during their quiescence intervals. We discuss the line identifications in their spectra and attempt to characterize the source(s) of their FUV flux distribution. Archival IUE spectrum of CH UMa and BV Cen in quiescence were identified as having a matching flux level with the FUSE spectra and these were combined with each FUSE spectrum to broaden the wavelength coverage and further constrain model fits. Multi-component synthetic spectral fits from our model grids, consisting of single temperature white dwarfs, two-temperature white dwarfs, accretion disks and white dwarfs plus accretion disks, were applied to the FUSE spectra alone and to the combined FUSE + IUE spectra. We present the results of our model analyses and their implications. Subject headings: accretion, accretion disks novae, cataclysmic variables stars: dwarf novae stars: individual (UU Aql, BV Cen, CH UMa) white dwarfs Based on observations made with the NASA-CNES-CSA Far Ultraviolet Spectroscopic Explorer. FUSE is operated for NASA by the Johns Hopkins University under NASA contract NAS5-32985 Visiting at the Space Telescope Science Institute, Baltimore, MD 21218, USA; [email protected]