EDP Sciences
Free access
Volume 398, Number 1, January IV 2003
Page(s) 305 - 314
Section Diffuse matter in space
DOI http://dx.doi.org/10.1051/0004-6361:20021627

A&A 398, 305-314 (2003)
DOI: 10.1051/0004-6361:20021627

On the measurement bias of low- $\ell$ solar $\vec{p}$-mode excitation parameters: The impact of a ground-based window function

W. J. Chaplin1, Y. Elsworth1, G. R. Isaak1, B. A. Miller1, R. New2, B. Pintér2 and S. Thiery1, 3

1  School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
2  School of Science & Mathematics, Sheffield Hallam University, Sheffield S1 1WB, UK
3  Institut d'Astrophysique Spatiale, Université Paris XI, 91405 Orsay, France

(Received 20 August 2002 / Accepted 6 November 2002 )

We present a study of the impact of a ground-based, multi-station window function on estimates of the power and damping of low- $\ell$ solar p modes extracted from fits to resonant structure in the frequency domain. The window functions come from six-site observations made by the Birmingham Solar-Oscillations Network (BiSON) over the 10-yr period beginning 1991 January. Two strategies were adopted. In the first, we used an 800-d time series of continuous observations made by the GOLF instrument on board the ESA/NASA SOHO satellite. These data were modulated by a variety of BiSON window functions, with fractional duty cycles ranging from ~ 0.4 to ~ 0.8, and the resulting series analyzed. In the second we generated artificial 10-yr time series and studied the effect on these of the complete BiSON window.

Key words: methods: data analysis -- Sun: oscillations

Offprint request: W. J. Chaplin, wjc@bison.ph.bham.ac.uk

© ESO 2003