Follow Us| UU Aql | ||||||||||||||||||
| The FUSE spectrum of the U Gem-type dwarf nova UU Aquilae was taken during quiescence. The spectrum is very noisy at the shorter wavelengths. The sharp emission lines are geo- and helio-coronal in origin. We identify ISM hydrogen molecular absorption features affecting the spectrum over almost the entire FUSE range. We note the absence of the C iii 1175 absorption line. The spectrum was modeled using a single WD component. Details on the processing and spectral modeling of the FUSE spectrum of UU Aql are given in Sion et al. (2007). In a first model (shwon here) we assumed a 1 solar mass WD (log(g)= 8.6) with solar composition except for C=0.001 solar. We obtain a temperature of 29,000K and a distance of 380pc. When we assume a canonical mass of 0.6 solar mass, we obtain a temperature of 26,000K and a distance of 450pc (this model is very similar to the 1 solar mass model). The apparent discrepancy between the model and the observed spectrum shortward of 1040A is due mainly to ISM Hydrogen molecular absorption. The Si iii and S iv lines between 1100A and 1150A are relatively well modeled. | |||||||||||||||||
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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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