Next: Introduction
Maximum Likelihood Estimation of Galaxy Morphology: Faint HST
Wide Field Camera Images
Kavan U. Ratnatunga, Richard E. Griffiths, and Stefano Casertano
Center for Astrophysical Sciences, Johns Hopkins University,
Baltimore, MD 21218
Abstract:
A modeling approach based on the maximum likelihood method has been
developed to extract quantitative morphological and structural parameter
estimates for faint galaxy images obtained with the Hubble Space
Telescope (HST) Wide Field Planetary Camera (WFPC). We model both the
galaxy image and the instrumental characteristics of the WFPC, including
the complex Point Spread Function (PSF), the error in the
Analog-to-Digital Converter (ADC), and the positive noise bias due to
faint cosmic rays and undetected warm pixels. Because convolved galaxy
images are compared directly with the observations, we avoid the need
for deconvolution, which is difficult and potentially unstable for faint
images.