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Pulsations of rapidly rotating stars with compositional discontinuities

Published online by Cambridge University Press:  18 February 2014

Daniel R. Reese
Affiliation:
Institut d'Astrophysique et Géophysique de l'Université de Liège, Allée du 6 Août 17, 4000 Liège, Belgium email: daniel.reese@ulg.ac.be
Francisco Espinosa Lara
Affiliation:
Universté de Toulouse, UPS-OMP, IRAP, Toulouse, France CNRS, IRAP, 14 avenue Edouard Belin, 31400 Toulouse, France
Michel Rieutord
Affiliation:
Universté de Toulouse, UPS-OMP, IRAP, Toulouse, France CNRS, IRAP, 14 avenue Edouard Belin, 31400 Toulouse, France
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Abstract

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Recent observations of rapidly rotating stars have revealed the presence of regular patterns in their pulsation spectra. This has raised the question as to their physical origin, and, in particular, whether they can be explained by an asymptotic frequency formula for low-degree acoustic modes, as recently discovered through numerical calculations and theoretical considerations. In this context, a key question is whether compositional/density gradients can adversely affect such patterns to the point of hindering their identification. To answer this question, we calculate frequency spectra using two-dimensional ESTER stellar models. These models use a multi-domain spectral approach, allowing us to easily insert a compositional discontinuity while retaining a high numerical accuracy. We analyse the effects of such discontinuities on both the frequencies and eigenfunctions of pulsation modes in the asymptotic regime. We find that although there is more scatter around the asymptotic frequency formula, the semi-large frequency separation can still be clearly identified in a spectrum of low-degree acoustic modes.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2014 

References

Breger, M., Fossati, L., Balona, L. A., et al. 2012, ApJ, 759, 62Google Scholar
Breger, M., Lenz, P., & Pamyatnykh, A. A. 2013, ApJ, 773, 56Google Scholar
Espinosa Lara, F. & Rieutord, M. 2013, A&A, 552, A35Google Scholar
García Hernández, A., Moya, A., Michel, E., et al. 2009, A&A, 506, 79Google Scholar
García Hernández, A., Moya, A., Michel, E., et al. 2013, A&A, 559, A63Google Scholar
Lignières, F. & Georgeot, B. 2008, Phys. Rev. E, 78, 016215Google Scholar
Lignières, F. & Georgeot, B. 2009, A&A, 500, 1173Google Scholar
Lignières, F., Rieutord, M., & Reese, D. 2006, A&A, 455, 607Google Scholar
Monteiro, M. J. P. F. G., Christensen-Dalsgaard, J., & Thompson, M. J. 1994, A&A, 283, 247Google Scholar
Pasek, M., Georgeot, B., Lignières, F., & Reese, D. R. 2011, Phys. Rev. Letters, 107, 121101Google Scholar
Pasek, M., Lignières, F., Georgeot, B., & Reese, D. R. 2012, A&A, 546, A11Google Scholar
Reese, D. R., Lignières, F., & Rieutord, M. 2008, A&A, 481, 449Google Scholar
Reese, D. R., MacGregor, K. B., Jackson, S., Skumanich, A., & Metcalfe, T. S. 2009, A&A, 506, 189Google Scholar
Reese, D. R., Espinosa Lara, F., & Rieutord, M. 2011, in: Neiner, C., Wade, G., Meynet, G., & Peters, G. (eds.), Active OB stars: structure, evolution, mass loss, and critical limits, Proc. IAU Symposium No. 272 (Cambridge: Cambridge University Press), p. 535Google Scholar
Rieutord, M. & Espinosa Lara, F. 2009, CoAst, 158, 99Google Scholar
Rieutord, M. & Espinosa Lara, F. 2013, Lecture Notes in Physics, 865, 49Google Scholar