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We present the high resolution spectra of the D type symbiotic stars V1016 Cygni and HM Sagittae obtained with the Bohyunsan Optical Echelle Spectrograph (BOES), and investigate the double-peaked asymmetric profiles of the Raman scattered O VI 6825. By adopting a wind accretion disk model, we assume that the O VI emission region is described by a Keplerian thin disk. The Raman scattering occurs in a neutral region near the giant, taking in the form of a slow stellar wind, part of which is ionized by the strong UV radiation from the hot white dwarf. Using a Monte Carlo technique, we compute the line profiles that are modulated by the slow spherical stellar wind from the giant component with the ionization front approximated by a hyperboloid. In order to account for the asymmetry and the existence of a central dip in the profiles, we add an O VI resonance scattering region between the hot white dwarf and the giant star which hinders the incidence of slightly blue O VI photons upon the H I region. Overall good fits to the observed data are obtained from our model, which lends support to the accretion disk emission model in these objects. The best fitting parameters for V1016 Cyg are $v_o=30{rm km s^{-1}}$, $v_infty=11{rm km s^{-1}}$, and $v_{c}=10{rm km s^{-1}}$, where $v_o$, $v_infty$ and $v_{c}$ are the velocity of the outer disk rim, the terminal velocity of the giant wind, and the velocity component of the resonance scattering O VI region along the binary axis, respectively. Similar fitting parameters $v_o=27{rm km s^{-1}}$, $v_infty=10{rm km s^{-1}}$ and $v_{c}=9{rm km s^{-1}}$ are obtained for HM Sge. We also investigate the effect of a hot spot in a disk that is well known in accretion disks in cataclysmic variables.
We present high resolution spectroscopy of the yellow symbiotic star AG Draconis with ESPaDOnS at the {it Canada-France-Hawaii Telescope}. Our analysis is focused on the profiles of Raman scattered ion{O}{VI} features centered at 6825 AA and 7082 AA,
The symbiotic system HM Sagittae consists of a Mira star and a secondary White Dwarf component. The dust content of the system was severely affected by the nova outburst in 1975, which is still ongoing. The capabilities of optical interferometry oper
We critically examine the recent claimed detection of Raman scattered O VI at around 6830AA in the iron curtain stage spectra of the classical CO nova V339 Del. The observed line variations are compatible in profile and timing of emission line streng
We present high spatial resolution observations of the mid-infrared core of the dusty symbiotic system HM Sge. The MIDI interferometer was used with the VLT UTs and ATs providing baselines oriented from PA=42° to 105°. The MIDI visibilities a
This paper reports the first study of the O VI resonance line emission (1032, 1038 Angstroms) originating in the Local Bubble (or Local Hot Bubble) surrounding the solar neighborhood. In spite of the fact that O VI absorption within the Local Bubble