[en] Corot and Kepler observations of red giants reveal rich spectra of non-radial solar-like oscillations allowing to probe their internal structure.
The study of non-adiabatic and energetic aspects of these oscillations is of great importance to predict not only the frequencies but also the FWMH and Heights of the peaks in power spectrum. This two observables are indeed directly related to modes lifetimes, necessitating a non-adiabatic approach. The height also depends on the energy injected in the mode by the turbulence in the upper convective-zone. We use a stochastic excitation model to compute the amplitudes of each modes.
We investigate the differences in power spectrum between an RGB and an HB stars with the same global parameters. We also follow the evolution of a star on the RGB and investigate the effect of its ascension on theoretical power spectrum to predict when on the RGB are mixed-modes more likely to be detectable.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Grosjean, Mathieu ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique stellaire théorique et astérosismologie
Dupret, Marc-Antoine ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique stellaire théorique et astérosismologie
Language :
English
Title :
Non-radial non-adiabatic solar like oscillations in red giants : Evolutionnary effects on theoretical power spectrum.
Publication date :
2012
Event name :
Belgian Asteroseismology Group meeting
Event date :
6 décembre 2012
Funders :
FRIA - Fonds pour la Formation à la Recherche dans l'Industrie et dans l'Agriculture