Seismic Holography of the Solar Interior near the Maximum and Minimum of Solar Activity

Díaz Alfaro, M.; Pérez Hernández, F.; González Hernández, I.; Hartlep, T.
Referencia bibliográfica

Solar Physics, Volume 291, Issue 5, pp.1323-1340

Fecha de publicación:
5
2016
Revista
Número de autores
4
Número de autores del IAC
2
Número de citas
1
Número de citas referidas
1
Descripción
The base of the convection zone and the tachocline play a major role in the study of the dynamics of the Sun, especially in the solar dynamo. Here, we present a phase-sensitive helioseismic holography method to infer changes in the sound-speed profile of the solar interior. We test the technique using numerically simulated data by Zhao et al. ( Astrophys. J. 702, 1150, 2009) with sound-speed perturbations at 0.7 R_{⊙}. The technique adequately recovers the perturbed sound-speed profile and is seen to be capable of detecting changes in the sound speed as low as 0.05 %. We apply the method to two GONG solar time series of approximately one year, each comprising 13 Bartels rotations, BR2295-BR2307 and BR2387-BR2399, near the maximum and at a minimum of solar activity, respectively. We successfully recover a sound-speed variation with respect to a standard solar model, consistent with previous results. However, we fail to recover a realistic sound-speed variation between maximum and minimum.