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Paper: |
On the Interpretation of Cool, Helium-rich White Dwarfs Showing Traces of Hydrogen |
Volume: |
509, 20th European Workshop on White Dwarfs (EuroWD16) |
Page: |
215 |
Authors: |
Rolland, B.; Bergeron, P.; Fontaine, G. |
Abstract: |
We present a spectroscopic analysis of cool (Teff<12,000 K) helium-rich white dwarfs — drawn mostly from the Sloan Digital Sky Survey (SDSS) — also showing spectroscopic traces of hydrogen. We then perform numerical simulations and attempt to interpret these objects (1) in terms of DA white dwarfs whose thin hydrogen atmospheres have been convectively mixed with the deeper and more massive helium envelope, or (2) in terms of DB or DBA stars that have simply cooled off, taking into account the possible accretion of hydrogen from the interstellar medium or other external sources. We also investigate the origin of DBA stars. |
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