Stellar elemental abundance determination using a Fabry-Pérot Interferometer
Degree GrantorUniversity of Canterbury
Degree NameMaster of Science
The Fabry-Pérot interferometer (FPI) was investigated as a potential tool for determining stellar elemental abundances. The FPI is a tunable narrow-band filter that makes it possible to obtain hundreds of stellar spectra simultaneously without the overhead associated with other multi-object spectroscopy techniques. This thesis used simulations and previously acquired data to investigate the FPI and develop data reduction techniques.
Using observations of a CaII spectral line, an algorithm was created for fitting a Voigt profile to the spectrum segments. The values for radial velocity & equivalent width were compared to the values found by the group who supplied the data and found to agree well for the radial velocity values but there was some definite scatter in the equivalent width. These differences are attributed to different placement of the continuum level in the spectra.
This curve-fitting script was modified to allow the fitting of synthetic spectra to simulated data. In this way it was possible to investigate how precise the abundance determination will be using the Robert Stobie Spectrograph's FPI mode. Large simulations showed that it will be possible to determine abundances to uncertainties of ±0.1 dex. This is an excellent result and should mean that future work using the FPI will give the results desired for large-scale s-process elemental abundance determination in globular cluster stars.