Far Ultraviolet Spectroscopy of Three Long Period Nova-Like Variables

Abstract

We have selected three nova-like variables at the long period extreme of nova-like orbital periods: V363 Aur, RZ Gru and AC Cnc, all with IUE archival far ultraviolet spectra. All are UX UMa type nova-like variables and all have $P_{orb}>7$h. V363 Aur is a bona fide SW Sex star, and AC Cnc is a probable one, while RZ Gru has not proven to be a member of the SW Sex subclass. We have carried out the first synthetic spectral analysis of far ultraviolet spectra of the three systems using state-of-the-art models both of accretion disks and white dwarf photospheres. We find that the FUV spectral energy distribution of both V363 Aur and RZ Gru are in agreement with optically thick steady state accretion disk models in which the luminous disk accounts for 100% of the FUV light. We present accretion rates and model-derived distances for V363 Aur and RZ Gru. For AC Cnc, we find that a hot accreting white dwarf accounts for $\sim$ 60% of the FUV light with an accretion disk providing the rest. We compare our accretion rates and model-derived distances with estimates in the literature.

Accepted for publication in the PASP (February 2012 issue)

References in corpus (6)

• The Donor Stars of Cataclysmic Variables
• Spectroscopic search for new SW Sextantis stars in the 3-4 hour orbital period range -- I
• A new absolute magnitude calibration with 2MASS for cataclysmic variables
• An International Ultraviolet Explorer Archival Study of Dwarf Novae in Outburst
• Far Ultraviolet Spectroscopy of Seven Nova-Like Variables
• A critical analysis of three near-infrared photometric methods of estimating distances to cataclysmic variables

Cited by in corpus (3)

• On the M_V -- Inclination Relationship for Nova-like Variables
• Far-Ultraviolet Spectroscopy of the Nova-Like Variable KQ Monocerotis: A New SW Sextantis Star?
• Hubble Space Telescope Cosmic Origins Spectrograph Spectroscopy of the Southern Nova-like BB Doradus in an Intermediate State