An Investigation into the mp Scale of Volume I of Zwicky et al.'s
Catalog of Galaxies and Clusters of Galaxies
Christopher Ke-shih Young and Zheng-yi Shao, PASA, 18 (2), in press.
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Title/Abstract Page: Total Magnitudes of Virgo
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Introduction
Zwicky et al.'s (1961-1968) Catalog of Galaxies and Clusters of Galaxies (hereunder CGCG) is still one of the most important sources of magnitude measurements of bright galaxies even today. Its mp values are now however, seldom used without the prior application of transformation equations. As B-band total magnitudes of galaxies are used for a large number of applications (e.g. galaxy luminosity functions), most studies of the CGCG's magnitude scales to date have therefore been concerned with whether mp values can reliably be transformed into B-band total magnitude estimates. This is in spite of the fact that Zwicky et al. (1961) did not actually claim mp values to be estimates of total apparent luminosity. As reviewed by Bothun & Cornell (1990), there has long been much debate over the reliability of the CGCG's magnitude measurements, particularly at the faint end. Also, the situation appears to be complicated by systematic differences between individual volumes of the catalogue, as noticed by Kron & Shane (1976) and Takamiya et al. (1995). Such issues clearly have implications for the self-consistency of magnitude scales based on transformed mp values such as those of the Reference Catalogs of Bright Galaxies of de Vaucouleurs et al. (1976, 1991). In this paper we investigate the degree of completeness of the CGCG as a function of magnitude as well as the nature of CGCG magnitude scale, with the benefit of the new Virgo-galaxy dataset of reliable total-magnitude measurements and detailed luminosity-profile information presented in Paper I of this series by Young (2000). Most of Virgo is covered by Volume I of the CGCG, but the northern extremity ( 
) is covered by Volume II. As most of our sample galaxies are Volume I objects, our investigations are limited primarily to Volume I.
Next Section: Our galaxy samples and
Title/Abstract Page: Total Magnitudes of Virgo
Previous Section: Total Magnitudes of Virgo
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