Generating On-the-fly Large Samples of Theoretical Spectra through an N-Dimensional Grid

Ching-Wa Yip
Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218, USA
E-mail: cwyip@pha.jhu.edu

ABSTRACT. Many analyses and parameter estimations undertaken in astronomy require a large set (gsim105) of non-analytical, theoretical spectra, each of these defined by multiple parameters. We describe the construction of an N-dimensional grid which is suitable for generating such spectra. The theoretical spectra are designed to correspond to a targeted parameter grid but otherwise to random positions in the parameter space, and they are interpolated on the fly through a pre-calculated grid of spectra. The initial grid is designed to be relatively low in parameter resolution and small in occupied hard disk space and therefore can be updated efficiently when a new model is desired. In a pilot study of stellar population synthesis of galaxies, the mean square errors on the estimated parameters are found to decrease with the targeted grid resolution. This scheme of generating a large model grid is general for other areas of studies, particularly if they are based on multi-dimensional parameter space and are focused on contrasting model differences.

Key words: methods: data analysis; techniques: spectroscopic

Print publication: Issue 2 (2010 February)
Received 2009 October 14, accepted for publication 2009 November 6
Published 2009 December 21

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