On The Impact Of 22Ne On The Pulsation Periods Of Carbon-Oxygen White Dwarfs With Helium Dominated Atmospheres. (arXiv:2101.08352v1 [astro-ph.SR])

On The Impact Of 22Ne On The Pulsation Periods Of Carbon-Oxygen White Dwarfs With Helium Dominated Atmospheres. (arXiv:2101.08352v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Chidester_M/0/1/0/all/0/1">Morgan T. Chidester</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Timmes_F/0/1/0/all/0/1">F.X. Timmes</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schwab_J/0/1/0/all/0/1">Josiah Schwab</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Townsend_R/0/1/0/all/0/1">Richard H.D. Townsend</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Farag_E/0/1/0/all/0/1">Ebraheem Farag</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Thoul_A/0/1/0/all/0/1">Anne Thoul</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fields_C/0/1/0/all/0/1">C.E. Fields</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bauer_E/0/1/0/all/0/1">Evan B. Bauer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Montgomery_M/0/1/0/all/0/1">Michael H. Montgomery</a>

We explore changes in the adiabatic low-order g-mode pulsation periods of
0.526, 0.560, and 0.729 M$_odot$ carbon-oxygen white dwarf models with
helium-dominated envelopes due to the presence, absence, and enhancement of
$^{22}$Ne in the interior. The observed g-mode pulsation periods of such white
dwarfs are typically given to 6$-$7 significant figures of precision. Usually
white dwarf models without $^{22}$Ne are fit to the observed periods and other
properties. The root-mean-square residuals to the $simeq$ 150$-$400 s
low-order g-mode periods are typically in the range of $sigma_{rms}$
$lesssim$ 0.3 s, for a fit precision of $sigma_{rms}/ P$ $lesssim$ 0.3 %. We
find average relative period shifts of $Delta P/P$ $simeq$ $pm$ 0.5 % for
the low-order dipole and quadrupole g-mode pulsations within the observed
effective temperature window, with the range of $Delta P/P$ depending on the
specific g-mode, abundance of $^{22}$Ne, effective temperature, and mass of the
white dwarf model. This finding suggests a systematic offset may be present in
the fitting process of specific white dwarfs when $^{22}$Ne is absent. As part
of the fitting processes involves adjusting the composition profiles of a white
dwarf model, our study on the impact of $^{22}$Ne can provide new inferences on
the derived interior mass fraction profiles. We encourage routinely including
$^{22}$Ne mass fraction profiles, informed by stellar evolution models, to
future generations of white dwarf model fitting processes.

We explore changes in the adiabatic low-order g-mode pulsation periods of
0.526, 0.560, and 0.729 M$_odot$ carbon-oxygen white dwarf models with
helium-dominated envelopes due to the presence, absence, and enhancement of
$^{22}$Ne in the interior. The observed g-mode pulsation periods of such white
dwarfs are typically given to 6$-$7 significant figures of precision. Usually
white dwarf models without $^{22}$Ne are fit to the observed periods and other
properties. The root-mean-square residuals to the $simeq$ 150$-$400 s
low-order g-mode periods are typically in the range of $sigma_{rms}$
$lesssim$ 0.3 s, for a fit precision of $sigma_{rms}/ P$ $lesssim$ 0.3 %. We
find average relative period shifts of $Delta P/P$ $simeq$ $pm$ 0.5 % for
the low-order dipole and quadrupole g-mode pulsations within the observed
effective temperature window, with the range of $Delta P/P$ depending on the
specific g-mode, abundance of $^{22}$Ne, effective temperature, and mass of the
white dwarf model. This finding suggests a systematic offset may be present in
the fitting process of specific white dwarfs when $^{22}$Ne is absent. As part
of the fitting processes involves adjusting the composition profiles of a white
dwarf model, our study on the impact of $^{22}$Ne can provide new inferences on
the derived interior mass fraction profiles. We encourage routinely including
$^{22}$Ne mass fraction profiles, informed by stellar evolution models, to
future generations of white dwarf model fitting processes.

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