Follow Us| P831 57 | ||||||||||||||||||
| The FUSE spectrum of the DA WD + dMe binary P831 57 was taken as part of a NL FUSE survey as the system was classified as a NL. From the present analysis it was found that the system does not have a disk and the WD is accreting from the wind of the secondary. The system also appears in the Downes catalog of CVs as a NL called Ret 1, and it is also known under the name WD 0334-6400. The spectrum together with the model is shown and details on the analysis can be found in Barrett et al. 2012. On the figure the following lines are marked but are NOT identified: N iv (923), S vi (933, 944), O vi doublet. All the sharp emissin lines are either helio coronal or air glow. The spectral feature around 1152A is a well known fixed pattern noise (FPN) in FUSE, a smaller FPN feature is also detected around 1072A. Since the WD has an extremely low rotation rate, its absorption lines are very sharp, similar to ISM lines. However, only the WD lines match the theoretical spectrum: C iii (977, 1175), N iii + He ii (990), Si iii (995), S iv (1006), C ii (1010), C ii (1036), S iv (1063, 1073), Si iv (1066), N ii + He ii (1085), Si iii (1008, 1010, 1013), Si iv (1023, 1028) and N i (1134). Some of these lines are deeper in the observed spectrum than in the model, possibly an indication that they are superposed to ISM lines (e.g. C ii 1036, N i 1134). All the other sharp lines are from the ISM (N i 954, Ar i, etc..). | |||||||||||||||||
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FUSE Data
Synthetic Spectrum
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These data and models were published in the paper: Godon, P., Sion, E.M., Levay, K., Linnell, A.P., Szkody, P., Barrett, P.E., Hubeny, I., Blair, W.P. 2012, ApJS, in press; Barrett, P.E. et al., 2011, in preparation | ||||||||||||||||||||||||||||||||||||
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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