Bibcode
Belkacem, K.; Samadi, R.; Goupil, M. J.; Baudin, F.; Salabert, D.; Appourchaux, T.
Referencia bibliográfica
Astronomy and Astrophysics, Volume 522, id.L2
Fecha de publicación:
11
2010
Revista
Número de citas
11
Número de citas referidas
9
Descripción
Theoretical modeling of the driving processes of solar-like oscillations
is a powerful way of understanding the properties of the convective
zones of solar-type stars. In this framework, the description of the
temporal correlation between turbulent eddies is an essential ingredient
to model mode amplitudes. However, there is a debate between a Gaussian
or Lorentzian description of the eddy-time correlation function (Samadi
et al. 2003b, A&A, 403, 303; Chaplin et al. 2005, MNRAS, 360, 859).
Indeed, a Gaussian description reproduces the low-frequency shape of the
mode amplitude for the Sun, but is unsatisfactory from a theoretical
point of view (Houdek 2010, Ap&SS, 328, 237) and leads to other
disagreements with observations (Samadi et al. 2007, A&A, 463, 297).
These are solved by using a Lorentzian description, but there the
low-frequency shape of the solar observations is not correctly
reproduced. We reconcile the two descriptions by adopting the sweeping
approximation, which consists in assuming that the eddy-time-correlation
function is dominated by the advection of eddies, in the inertial range,
by energy-bearing eddies. Using a Lorentzian function together with a
cut-off frequency derived from the sweeping assumption allows us to
reproduce the low-frequency shape of the observations. This result also
constitutes a validation of the sweeping assumption for highly turbulent
flows as in the solar case.
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Los objetivos genéricos de este Proyecto son: 1) el estudio de la estructura y dinámica del interior solar, 2) la extensión de dicho estudio al caso de otras estrellas, 3) la búsqueda y caracterización de planetas extrasolares por métodos fotométricos (principalmente mediante el método de tránsitos) y espectroscópico (variaciones en la velocidad
Savita
Mathur