Abstract
It is presently widely accepted that the solar low ℓ p modes show asymmetric profiles when their power spectrum is analysed and that the fact of fitting symmetric profiles yields systematic effects in the obtained frequencies which could affect the results of inversions. In this paper the low ℓ p-mode profiles are analysed using wavelets to denoise the power spectra of the modes. This denoising method is applied both to artificial data generated by Kosovichev (the Hare and Hound exercise) and to real data obtained with the GOLF instrument. The asymmetries as well as the frequencies obtained are studied in both cases. The results show that although the obtained p-mode profiles present a slightly negative asymmetry, the use of symmetric profiles to fit the power spectra does not introduce any systematic effect in the obtained frequencies.
Similar content being viewed by others
References
Bertello, L., Henney, C. J., Ulrich, R. K., Varadi, F., Kosovichev, A. G., Scherrer, P. H., Roca Cortés, T., Thiery, S., Boumier, P., Gabriel, A. H., and Turck-Chièze, S.: 2000, Astrophys. J., submitted.
Christensen-Dalsgaard, J.: 1998, Proceeding of the SOHO6/GONG98, Workshop, Boston, p. 17.
Duvall, T. L., Jefferies, S. M., Harvey, J. W., Osaki, Y., and Pomerantz, M. A.: 1993, Astrophys. J. 410, 829.
Fligge, M. and Solanki, S. K.: 1997, Astron. Astrophys. Suppl. Ser. 124, 579.
Gabriel, A. H., Grec, G., Charra, J. et al.: 1995, Solar Phys. 162, 61.
Libbrecht, K. G.: 1992, Astrophys. J. 387, 712.
Mallat, St. and Zhong, S.: 1992, IEEE Trans Pattern Anal. Machine Intell. 14, 710.
Nigam, R. and Kosovichev, A. G.: 1998, Astrophys. J. 505, L51.
Thiery, S., Boumier, P., Gabriel, A. H., Bertello, L., Lazrek, M., Garcia, R. A., Robillot, J. M., Grec, G., Roca Cortes, T., Turck-Chieze, S., and Ulrich, R.K.: 2000, Astron. Astrophys. 355, 743.
Topping, J.: 1975, Errors of Observation and Their Treatment, Chapman and Hall, London.
Toutain, T., Appourchaux, T., Fröhlich, C., Kosovichev, A. G., Nigam R., and Scherrer, P. H.: 1998, Proceedings of the SOHO6/GONG98, Workshop, Boston, p. 973.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Régulo, C., Roca Cortés, T. Analysis of the solar low-ℓ p-mode asymmetries using wavelets. Solar Physics 200, 381–391 (2001). https://doi.org/10.1023/A:1010382506392
Issue Date:
DOI: https://doi.org/10.1023/A:1010382506392