Jingkun Zhao, Terry D. Oswalt, Lee Anne Willson, Qian Wang, Gang Zhao
We present the initial-final mass relation derived from 10 white dwarfs in
wide binaries that consist of a main sequence star and a white dwarf. The
temperature and gravity of each white dwarf was measured by fitting theoretical
model atmospheres to the observed spectrum using a $\chi^{2}$ fitting
algorithm. The cooling time and mass was obtained using theoretical cooling
tracks. The total age of each binary was estimated from the chromospheric
activity of its main sequence component to an uncertainty of about 0.17 dex in
log \textit{t} The difference between the total age and white dwarf cooling
time is taken as the main sequence lifetime of each white dwarf. The initial
mass of each white dwarf was then determined using stellar evolution tracks
with a corresponding metallicity derived from spectra of their main sequence
companions, thus yielding the initial-final mass relation. Most of the initial
masses of the white dwarf components are between 1 - 2 M$_{\odot}$. Our results
suggest a correlation between the metallicity of a white dwarf's progenitor and
the amount of post-main-sequence mass loss it experiences - at least among
progenitors with masses in the range of 1 - 2 M$_{\odot}$. A comparison of our
observations to theoretical models suggests that low mass stars preferentially
lose mass on the red giant branch.
View original:
http://arxiv.org/abs/1112.0281
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