THE CANADA-FRANCE REDSHIFT SURVEY .5. GLOBAL PROPERTIES OF THE SAMPLE

The Canada-France Redshift Survey is an unprecedentedly large sample of spectra of very faint 17.5 less than or equal to I-AB less than or equal to 22.5 objects in five separate fields in which 85% of the target objects are securely identified. The photometric and spectroscopic data discussed in earlier CFRS papers are combined in this paper, and analyses are carried out to verify the integrity of the sample so that it can be confidently used for future scientific investigations. The redshift histogram of the sample is presented for 591 field galaxies with secure redshifts. The median redshift is [z] = 0.56, and the highest redshift observed is z similar to 1.3; 25 galaxies have measured redshifts z > 1. The distributions of magnitudes and colors demonstrate that galaxies at these high redshifts have very similar colors to those observed locally. The survey thus represents a major improvement in our knowledge of field galaxies at large look-back times. Only similar to 1% of galaxies with 17.5 less than or equal to I-AB less than or equal to 22.5 are as compact as stars (on images with FWHM similar to 0''.9), and comparison of the photometric and spectroscopic data shows that only one galaxy was initially incorrectly classified spectroscopically as a star and only two stars were misclassified as galaxies. It is demonstrated that the redshift distributions in the five fields are statistically consistent with each other, once the reduction in the effective number of independent galaxies due to small-scale clustering in redshift is taken into account. The photometric properties of the spectroscopically unidentified objects (15% of the sample) indicate that most are likely to be galaxies rather than stars. At least half of these must have the same redshift distribution as the identified galaxies, and a combination of magnitudes, colors, and compactness of the remaining unidentified galaxies is used to predict their redshifts. The majority are probably ordinary galaxies at the high-redshift end of our sample, including some quiescent galaxies at z > 1.0, rather than some new or unusual population.