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Please use this identifier to cite or link to this item: http://hdl.handle.net/1942/2546

Title: Statistical revision of the moment method
Authors: De Ridder, Joris
Molenberghs, Geert
Aerts, Conny
Issue Date: 2003
Citation: ASTROPHYSICS AND SPACE SCIENCE, 284(1). p. 125-128
Abstract: The moment method is a well known technique, which uses a time series of the first 3 moments of a spectral line, to estimate the (discrete) mode parameters l and m. The method, contrary to Doppler imaging, also yields other interesting (real-valued) parameters such as the inclination angle i, or v sin i, during its identification procedure. In this paper, we are not only interested in the estimation of these real-valued parameters themselves but also in reliable estimates for their uncertainty. We designed a statistical formalism for the moment method based on the so-called generalized estimating equations (GEE). This formalism aims to estimate the uncertainty of the real-valued parameters taking into account that the different moments of a line profile are correlated and - more importantly - that the uncertainty of the observed moments depends on the pulsation parameters. The latter property of the moment method makes the least-squares technique a poor choice to estimate the uncertainty of the real-valued parameters. We implemented the GEE method and present an application to a high-resolution spectroscopic dataset of the slowly pulsating B star HD181558.
Notes: Katholieke Univ Leuven, Inst Astron, B-3001 Louvain, Belgium. Limburgs Univ Ctr, Ctr Stat, B-3590 Diepenbeek, Belgium.De Ridder, J, Katholieke Univ Leuven, Inst Astron, Celestijnenlaan 200 B, B-3001 Louvain, Belgium.
URI: http://hdl.handle.net/1942/2546
DOI: 10.1023/A:1023210812440
ISI #: 000182071400017
ISSN: 0004-640X
Category: A1
Type: Journal Contribution
Validation: ecoom, 2004
Appears in Collections: Research publications

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