Automated analysis of objective-prism spectra - I. Quasar detection

Abstract

A fully automated system for the location, measurement and analysis of large numbers of low-resolution objective-prism spectra is described. The system is based on the APM facility at the University of Cambridge, and allows processing of objective-prism, grens or grism data. Particular emphasis is placed on techniques to obtain the maximum signal-to-noise ratio from the data, both in the initial spectral estimation procedure and for subsequent feature identification. Precise wavelength scales for each spectrum and the definition of magnitude-limited samples simplify subsequent analysis considerably.