LOW-DEGREE, L=4 MODES IN FULL-DISC BISON HELIOSEISMOLOGICAL DATA

Citation
Wj. Chaplin et al., LOW-DEGREE, L=4 MODES IN FULL-DISC BISON HELIOSEISMOLOGICAL DATA, Monthly Notices of the Royal Astronomical Society, 280(4), 1996, pp. 1162-1166
Citations number
16
Categorie Soggetti
Astronomy & Astrophysics
ISSN journal
00358711
Volume
280
Issue
4
Year of publication
1996
Pages
1162 - 1166
Database
ISI
SICI code
0035-8711(1996)280:4<1162:LLMIFB>2.0.ZU;2-S
Abstract
We demonstrate that some l=4 acoustic eigenmodes of the Sun are clearl y distinguishable in long power spectra generated from Doppler velocit y residuals collected in unimaged sunlight by the six-station Birmingh am Solar Oscillations Network (BiSON). Modes covering the range n=17 t o 21 have been measured in 16-month-long power spectra. They have typi cal amplitudes - when measured in full-disc Doppler velocity data - of less than similar to 1 cm s(-1) per root bin, and their frequencies h ave been determined to fractional accuracies of the order of 3 parts i n 10(5). The sensitivity of the whole-disc observations to these modes - as implied by the data - appears to be approximately a factor of 2 greater than the theoretical predictions of Christensen-Dalsgaard.