Follow Us| BV Cen | ||||||||||||||||||
| The FUSE Spectrum of the U Gem dwarf nova BV Centauri was taken in quiescence. The spectrum is very noisy especially at the shorter wavelengths. The increase of flux at at 920A is probably due to a background subtraction problem. We identify ISM Hydrogen molecular absorption features as well as some ISM iron lines. The sharp emission lines are due to terrestrial airglow. The broad O vi doublet and C iii (977A) are from the source. The S iv (1073), Si iii (1113), Si iv (1123 & 1128) and C iii (1175) absorption spectra features are all identified. All the other absorption features marked on the figure are suggestive and are not detected. The modeling takes into account the larger mass recently found of 1.24 Msun, this does not change the temperature of the WD appreciably, but it reduces the distance to about 200 pc. The modeling includes the effect of the ISM. The theoretical spectrum compared to the observed one consists in the spectral regions colored in red (in the second figure). Details on the processing and spectral modeling of the FUSE spectrum are given in Sion et al. 2007. | |||||||||||||||||
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FUSE Data
Synthetic Spectrum
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These data and models were published in the paper: Sion, E.M., Godon, P., Cheng, F., Skzody, P. 2007, ApJ, 134, 886 | ||||||||||||||||||||||||||||||||||||
Notes on figures:The flux (vertical axis) is given in ergs/sec/cm2/A and the wavelength (horizontal axis) is given in Angstroem. For clarity the spectrum is shown on 3 panels: the upper panel from about 900 to 1000A, the middle panel from about 1000A to 1100A, and the lower panel from about 1100A to 1200A. Air glow emission is anoted above each panel with a "+" sign inside a circle. Strong emission lines reaching the upper part of the frame in each pael is marked just above the panel. The Hydrogen series is marked below the x-axis in the upper and middle panel and the hydrogen cut-off limit is clearly marked around 915A with an increasing density of tick marks. The He I (1168A) is marked below the lower panel. Oxygen I lines are shown with an arrow "OI -->" if many (ISM) OI lines are present, they are just annotated with verical tick marks in the lower portion of each panel. ISM molecular hydrogen lines are either individually annotated vertically (e.g. L10R1) or just marked with an arrow "MH -->" and vertical tick marks (usually in the upper part of each panel). Features resulting from fixed pattern noise introduced by FUSE detect ors are indicated with "FPN;.When a model is shown, the portions of the observed spectrum that have been masked before the spectral fit are in blue, while the rest of the observed spectrum is in red. The model fit is shown the solide line in black (or possibly white). If the model is a composite made of a disk model and a white dwarf model, then these are shown with the dashed- and dotted lines (respectively). Some models include the effect of quasi-molecular HI absorption features, these are labelled "Q-mol" in the spectrum. |
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