Abstract

With the appearance of CCD-based astronomical spectrographs, faint object spectroscopy has entered a new era. We are now able to do spectroscopy of objects as faint as m ≈ 24, and possibly even fainter. Improvement over the previous generation of the astronomical spectrographs is easily a factor of 10 or 20. This gain is mostly due to three factors : 1) high quantum efficiencies of CCDs (30-40%), 2) their enhancement-friendly white noise properties, and 3) ability to do local sky subtraction, thanks to their 2-dim. imaging nature. In this paper, we would like to share our experiences in long-slit CCD spectroscopy, hoping that they may be of some use to others. We do not discuss the aperture plate work, but the procedures outlined here do apply to multiple slit spectroscopy.

© 1983 Optical Society of America