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Please use this identifier to cite or link to this item: http://hdl.handle.net/1942/4035

Title: Estimating stellar parameters from spectra using a hierarchical Bayesian approach
Authors: Shkedy, Ziv
Decin, L.
Molenberghs, Geert
Aerts, Conny
Issue Date: 2007
Abstract: A method is developed for fitting theoretically predicted astronomical spectra to an observed spectrum. Using a hierarchical Bayesian principle, the method takes both systematic and statistical measurement errors into account, which has not been done before in the astronomical literature. The goal is to estimate fundamental stellar parameters and their associated uncertainties. The non-availability of a convenient deterministic relation between stellar parameters and the observed spectrum, combined with the computational complexities this entails, necessitates the curtailment of the continuous Bayesian model to a reduced model based on a grid of synthetic spectra. A criterion for model selection based on the so-called predictive squared error loss function is proposed, together with a measure for the goodness-of-fit between observed and synthetic spectra. The proposed method is applied to the infrared 2.38-2.60 mu m Infrared Space Observatory (ISO)-Short Wavelength Spectrometer (SWS) data of the star alpha Bootis, yielding estimates for the stellar parameters: effective temperature T-eff = 4230 +/- 83 K, gravity log g = 1.50 +/- 0.15 dex and metallicity [Fe/H] = - 0.30 +/- 0.21 dex.
Notes: Hasselt Univ, Ctr Stat, B-3590 Diepenbeek, Belgium. Katholieke Univ Leuven, Inst Astron, Dept Phys & Astron, B-3001 Heverlee, Belgium.SHKEDY, Z, Hasselt Univ, Ctr Stat, B-3590 Diepenbeek, Belgium.ziv.shkedy@uhasselt.be Leen.Decin@ster.kuleuven.be
URI: http://hdl.handle.net/1942/4035
DOI: 10.1111/j.1365-2966.2007.11508.x
ISI #: 000246797900027
ISSN: 0035-8711
Category: A1
Type: Journal Contribution
Validation: ecoom, 2008
Appears in Collections: Research publications

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