patrick gaulme edited subsubsection_Mixed_oscillation_modes_label__.tex  over 8 years ago

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\revise{To more accurately assess the evolutionary stage of KIC 9246715, we perform a Bayesian fit to the individual oscillation modes of the star using the \textsc{D\large{iamonds}} code \citep{cor14} and the methodology for the peak bagging analysis of a red giant star in \citet{cor15}. We then compare the set of the obtained frequencies of mixed dipole modes with those from the asymptotic relation proposed by \citet{mos12}, which we compute using different values of $\Delta \Pi_1$. The result shows a significant better matching when values of $\Delta \Pi_1$ around $200 \ \rm{s}$ are used. This confirms that the oscillating star is settled on the core-He-burning phase of stellar evolution.} This result is supported statistically by \citet{mig14}, who report it is more likely to find red clump stars than red giant branch stars in asteroseismic binaries in \emph{Kepler} data. This is largely due to the fact that evolved stars spend more time on the horizontal branch than the red giant branch. We note that due to the large noise level of the mixed modes, we are unable to measure a core rotation rate in the manner of \citet{bec12} and \citet{mos12}.   {\textbf{BENOIT  The use of the universal red giant oscillation pattern \citep{2011A&A...525L...9M} for analyzing the spectrum of KIC 9246715 provided the measurement of the large separation $\Dnu = 8.33 \pm 0.04\,\mu$Hz, but also exhibited many supernumerary peaks. As soon as it was clear that these peaks cannot be mixed modes, the hypothesis of a binary companion was tested. Again, the universal oscillation pattern allowed us to allocate the supernumerary peaks to a pressure-mode oscillation pattern based on $\Dnu= 8.62\pm 0.04\,\mu$Hz. The spectra are globally interlaced, with the dipole modes of one component close to the radial modes of the other component, and conversely.  We then measured the asymptotic period spacing with the new method developed by \cite{2015arXiv150906193M}. The signature $\Delta\Pi_1 = 150.4\pm1.4$\,s is very clear, despite binarity. In fact, the secondary spectrum cannot mimic a mixed-mode pattern and its global amplitude is small, so that the disturbance is limited. Only one signature is visible, which corresponds to the main component. }}  \subsubsection{Identifying the oscillating star}\label{identifying}  The asteroseismic mass and surface gravity are consistent with those from the ELC model for both stars, while the asteroseismic radius is only consistent with Star 2. Neither star's mean density agrees with the asteroseismic value, but Star 2 is much closer than Star 1. Overall, our asteroseismic analysis suggests the oscillating star is Star 2. However, we cannot definitely conclude this without considering the temperature dependence of the scaling relations. From \citet{gau13}, \citet{gau14}, and the present work, asteroseismic masses and radii were reported to be $(1.7 \pm 0.3 \ M_\odot, 7.7 \pm 0.4 \ R_\odot)$, $(2.06 \pm 0.13 \ M_\odot, 8.10 \pm 0.18 \ R_\odot)$, and $(2.17 \pm 0.12 \ M_\odot, 8.26 \pm 0.16 \ R_\odot)$, respectively. Among these, $\nu_{\rm{max}}$ does not vary much ($102.2, 106.4, 106.4 \ \mu\rm{Hz}$), and $\Delta \nu$ varies even less ($8.3, 8.32, 8.31 \ \mu\rm{Hz}$), while the assumed temperatures were 4699 K (from the KIC), 4857 K (from \citealt{hub14.2}), and 5000 K (this work).