An attempt to identify low L - low N solar acoustic modes

Anguera Gubau, M.; Palle, P. L.; Perez Hernandez, F.; Roca-Cortés, T.
Referencia bibliográfica

(IAU, The Inside the Sun Colloquium, 121st, Versailles, France, May 22-26, 1989) Solar Physics (ISSN 0038-0938), vol. 128, July 1990, p. 79-90.

Fecha de publicación:
Número de autores
Número de autores del IAC
Número de citas
Número de citas referidas
The low l solar acoustic spectrum has been measured with great accuracy for intermediate radial order modes, n = 11-34 (Jimenez et al., 1986; Grec et al., 1983; Palle et al., 1986). The measurement of the frequencies of modes of lower n, up to the fundamental one, are very important as they depart from asymptotic behavior and, therefore, put more severe constraints on solar models. However, their amplitudes are very low (under 2 cm/s) and when compared to the solar velocity background noise, an S/N of 1 is obtained. Taking advantage of the fact that lifetimes seem to be higher at lower frequencies (lower n values), very long Doppler velocity measurements, obtained at Teide Observatory, have been used to increase S/N, therefore, providing the possibility to detect such modes. The frequencies observed are compared to those predicted by a solar model (Christensen-Dalsgaard et al., 1988), using the best equation of state yet computed (Mihalas et al., 1988).