Hubble Space Telescope Observations of the Nova-Like Cataclysmic Variable V348 Puppis

Abstract

We present time series UV and optical (1150 -- 8000 A) spectrophotometry of the novalike (NL) cataclysmic variable V348 Pup through and after eclipse. Outside of eclipse, the spectrum is characterized by a blue continuum, strong line emission, and a broad dip from 2000 -- 3000 A. The continuum eclipse depth is roughly the same over the entire wavelength range covered and there are no signatures of the WD eclipse in the light curves. Model steady-state accretion disk spectra provide a poor fit to the shape of the UV-optical spectrum outside of eclipse. All of these properties are consistent with a disk that is self-shielding, hiding the inner disk and the white dwarf. In eclipse, the emission lines and the broad dip are occulted less than the continuum, indicating vertical extension in these components. The dip is consistent with the presence of a vertical ``Fe II'' absorbing curtain in the system. Archival UV-optical spectra of the lower-inclination NL UX UMa show a bluer continuum and weaker line emission than in V348 Pup and no broad dip. There is strong flickering in V348 Pup. The flickering spectrum shows that the flickering occurs only in the continuum. We did not detect any periodicities associated with the rapid variability. The properties of V348 Pup are consistent with its previous identification as a member of the SW Sex sub-class of NLs.