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Paper: |
A Spectroscopic Study of the Far-Ultraviolet Spectrum of the DAZ White Dwarf EG102 |
Volume: |
372, 15th European Workshop on White Dwarfs |
Page: |
261 |
Authors: |
Dupuis, J.; Bouabid, M.-P.; Wesemael, F.; Chayer, P. |
Abstract: |
EG 102 is a rare example of a hydrogen-rich atmosphere white dwarf showing weak lines of heavy elements (Ca II, Mg II, Si II) in its optical and ultraviolet spectra. With an effective temperature around 20,000 K and a normal surface gravity, it is difficult to explain the presence of these heavy elements in terms of radiative levitation. An explanation in terms of accretion from the interstellar medium or from a companion also runs into difficulties. The FUSE satellite has performed two observations of EG102 that reveal a wealth of photospheric absorption lines dominated by C, N, Si, and Fe. We present a spectral synthesis analysis of the far-ultraviolet spectrum, derive element abundances and discuss these results in terms of the accretion-diffusion theory applied to white dwarfs. |
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