Frequency ratio method for seismic modelling of γ Doradus stars. II. The role of rotation
Abstract
The effect of rotation on the Frequency Ratio Method (Moya et al. 2005, A&A, 432, 189) is examined. Its applicability to observed frequencies of rotating γ Doradus stars is discussed taking into account the following aspects: the use of a perturbative approach to compute adiabatic oscillation frequencies; the effect of rotation on the observational Brunt-Väisälä integral determination and finally, the problem of disentangling multiplet-like structures from frequency patterns due to the period spacing expected for high-order gravity modes in asymptotic regime. This analysis reveals that the FRM produces reliable results for objects with rotational velocities up to 70 {km s-1}, for which the FRM intrinsic error increases one order of magnitude with respect to the typical FRM errors given in Moya et al. (2005, A&A, 432, 189). Our computations suggest that, given the spherical degree ℓ identification, the FRM may be discriminating for m=0 modes, in the sense that the method avoids any misinterpretation induced by the presence of rotationally split multiplet-like structures, which reinforces the robustness of the method. However, if ℓ is unknown, such discrimination is not ensured. In order to check the FRM in presence of slow-moderate rotation, we have applied it to the three observed frequencies of the slowly rotating ({v sin i}=29 {km s-1}) γ Doradus star
- Publication:
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Astronomy and Astrophysics
- Pub Date:
- November 2005
- DOI:
- 10.1051/0004-6361:20053114
- arXiv:
- arXiv:astro-ph/0508482
- Bibcode:
- 2005A&A...443..271S
- Keywords:
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- stars: rotation;
- stars: oscillations;
- stars: fundamental parameters;
- stars: evolution;
- stars: individual: HD 48501;
- stars: general;
- Astrophysics
- E-Print:
- A&