Maximum Likelihood Estimation of Galaxy Morphology: Faint HST Wide Field Camera Images

Kavan U. Ratnatunga, Richard E. Griffiths, and Stefano Casertano

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.

Pages 333-336

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