Next: Introduction
Precision Photometry at the LMC Center: Simulating Post-COSTAR HST
Observations
P. Linde, R. Snel, and S. Spännare
Lund Observatory, Box 43, S-221 00, Lund, Sweden
Abstract:
We intend to use the restored HST to study age structure and chemical
evolution of the stellar population at the center of the LMC. To obtain
the necessary observational parameters, Strömgren photometry is
planned using the Planetary Camera. To study the reduction techniques
needed, a set of simulated PC images have been made. The stellar density
in the images is
based on an extrapolated luminosity function and show a high degree of
crowding. Two of the generally available photometric software packages,
ROMAFOT and DAOPHOT, have been used to analyse the images. Results show
that the photometric accuracy reached with these packages is not enough
for high precision photometry in this configuration. We show that the
two major contributors to the errors are undersampling and the unusual
shape of the point spread function. Adaptation of locally developed
software is currently in progress to deal with these problems.