A technique to determine the best stellar model (mass and age) match to an observed stellar oscillation spectrum

Abstract

Stellar non-radial oscillations (p-modes) are ideal tools to test theories of stellar evolution and to provide information about stellar properties. This thesis develops and tests a technique to determine the stellar model (which varies in mass and age only) whose pulsation spectrum best matches an observed pulsation spectrum. The best match of observed frequencies to a stellar model yields a mass and age for the observed star.

A method of direct comparison is used whereby a set of observed stellar p-modes are compared individually with p-modes calculated from stellar models. A grid of model frequencies calculated from stellar models that vary in mass and age only is required. This grid is the basis of comparison with observed stellar p-mode frequencies.

The quality of each comparison between observed frequencies and model spectra is characterized using a chi-squared best fit parameter where a low value denotes a good match. An overall minimum from the comparison of observed frequencies and model spectra identifies the best fit stellar model; therefore predicting mass and age values. (Abstract shortened by UMI.)