
%0 Journal Article
%A Ke-shih Young, Christopher 
%A Shao, Zheng-yi 
%T Total Magnitudes of Virgo Galaxies. II. An Investigation into the <emph type="2">m</emph><emph type="8">p</emph> Scale of Volume I of Zwicky <emph type="2">et al.</emph>'s Catalogue of Galaxies and of Clusters of Galaxies
%J Publications of the Astronomical Society of Australia
%D 2001/09/28
%V 18
%N 2
%P 129-135
%K catalogues &#8212; galaxies: clusters: individual (Virgo) &#8212; galaxies: fundamental parameters &#8212; galaxies: photometry
%R https://doi.org/10.1071/AS01031
%U https://www.publish.csiro.au/paper/AS01031 
%X Received 2000 May 3, accepted 2001 June 1 We investigate the photographic-magnitude (mp) scale of Volume I of the Catalogue of Galaxies and of Clusters of Galaxies for galaxies in the Virgo direction. It is found that for 11.5 &le; Bt &#60; 14.5, the mp values listed correspond very closely (with a scatter of only 0.16 magnitude) to blue magnitudes measured to the B = 24.4 isophote. If mp values need to be used as estimates of total blue magnitude the scatter is 0.27 magnitude over the same range in Bt and the mean offset is mp &#8211; Bt = 0.28 magnitude. However, a serious scale error at the bright end causes both the isophotal and total luminosities of galaxies brighter than Bt ~ 11.5 to be severely underestimated. At the faint end there also appears to be a significant scale error. This causes galaxy luminosities to be seriously overestimated faintward of Bt ~ 14.5.We demonstrate that this is a real effect based on a detailed galaxy-by-galaxy study of the catalogue&#8217;s completeness down to Bt = 17.0. The catalogue is found only to be complete to Bt ~ 14.7 whilst its degree of incompleteness is found to be relatively constant at the 30% level over the range 14.75 &le; Bt &#60; 15.75. Most of the missing objects are found to be elliptical galaxies and so late-type objects are over-represented at the faint end. 
