ORFEUS II and IUE Spectroscopy of EX Hydrae

Abstract

Using ORFEUS-SPAS II FUV spectra, IUE UV spectra, and archival EUVE deep survey photometry, we present a detailed picture of the behavior of the magnetic cataclysmic variable EX Hydrae. Like HUT spectra of this source, the FUV and UV spectra reveal broad emission lines of He II, C II-IV, N III and V, O VI, Si III-IV, and Al III superposed on a continuum which is blue in the UV and nearly flat in the FUV. Like ORFEUS spectra of AM Her, the O VI doublet is resolved into broad and narrow emission components. Consistent with its behavior in the optical, the FUV and UV continuum flux densities, the FUV and UV broad emission line fluxes, and the radial velocity of the O VI broad emission component all vary on the spin phase of the white dwarf, with the maximum of the FUV and UV continuum and broad emission line flux light curves coincident with maximum blueshift of the broad O VI emission component. On the binary phase, the broad dip in the EUV light curve is accompanied by strong eclipses of the UV emission lines and by variations in both the flux and radial velocity of the O VI narrow emission component. The available data are consistent with the accretion funnel being the source of the FUV and UV continuum and the O VI broad emission component, and the white dwarf being the source of the O VI narrow emission component.

21 pages, 10 Postscript figures; LaTeX format, uses aaspp4.sty; table2.tex included separately because it must be printed sideways - see instructions in the file; accepted on 1999 Feb 20 for publication in The Astrophysical Journal

References in corpus (2)

• Far-Ultraviolet Performance of the Berkeley Spectrograph During the ORFEUS-SPAS II Mission
• ORFEUS II Far-UV Spectroscopy of AM Herculis

Cited by in corpus (18)

• First Application of the Fe XVII I(17.10 A)/I(17.05 A) Line Ratio to Constrain the Plasma Density of a Cosmic X-ray Source
• Outbursts of EX Hydrae: mass-transfer events or disc instabilities?
• HST/STIS Spectroscopy of the Intermediate Polar EX Hydrae
• The Fe XXII I(11.92 A)/I(11.77 A) Density Diagnostic Applied to the Chandra High Energy Transmission Grating Spectrum of EX Hydrae
• Multi-wavelength spectrophotometry of EX Hydrae
• Dynamics of Line-Driven Winds from Disks in Cataclysmic Variables. I. Solution Topology and Wind Geometry
• The Radial Velocity and Mass of the White Dwarf of EX Hydrae Measured with Chandra
• Hubble Space Telescope and Ground-Based Observations of V455 Andromedae Post-Outburst
• Testing the cooling flow model in the intermediate polar EX Hydrae
• On the area of accretion curtains from fast aperiodic time variability of the intermediate polar EX Hya
• An Illustration of Modeling Cataclysmic Variables: HST, FUSE, SDSS Spectra of SDSSJ080908.39+381406.2
• An EUV Study of the Intermediate Polar EX Hydrae
• A Radial Velocity Study of the Intermediate Polar EX Hydrae
• Photoionized features in the X-ray spectrum of EX Hydrae
• X-ray Light Curves and Accretion Disk Structure of EX Hydrae
• Observations of the Magnetic Cataclysmic Variable VV Puppis with the Far Ultraviolet Spectroscopic Explorer
• Outbursts of EX Hydrae Revisited
• Current and secular accretion rates of EX Hydrae