The Updated Zwicky Catalog (UZC)

The Zwicky Catalog of galaxies (ZC), with mZw≤15.5, has been the basis for the Center for Astrophysics (CfA) redshift surveys. To date, analyses of the ZC and redshift surveys based on it have relied on heterogeneous sets of galaxy coordinates and redshifts. Here we correct some of the inadequacies of previous catalogs by providing (1) coordinates with ≲2 ″ errors for all of the 19,369 catalog galaxies, (2) homogeneously estimated redshifts for the majority (98%) of the data taken at the CfA (14,632 spectra), and (3) an estimate of the remaining “blunder” rate for both the CfA redshifts and for those compiled from the literature. For the reanalyzed CfA data we include a calibrated, uniformly determined error and an indication of the presence of emission lines in each spectrum. We provide redshifts for 7257 galaxies in the CfA2 redshift survey not previously published; for another 5625 CfA redshifts we list the remeasured or uniformly rereduced value. Among our new measurements, 1807 are members of UZC “multiplets” associated with the original Zwicky catalog position in the coordinate range where the catalog is 98% complete. These multiplets provide new candidates for examination of tidal interactions among galaxies. All of the new redshifts correspond to UZC galaxies with properties recorded in the CfA redshift compilation known as ZCAT. About 1000 of our new measurements were motivated either by inadequate signal‐to‐noise in the original spectrum or by an ambiguous identification of the galaxy associated with a ZCAT redshift. The redshift catalog we include here is ∼96% complete to mZw≤15.5 and ∼98% complete (12,925 galaxies out of a total of 13,150) for the right ascension ranges 20h≥α1950≤4h and 8h≥α1950≤17h and declination range - 2.°5≤δ1950≤50°. This more complete region includes all of the CfA2 survey as analyzed to date. The Great Wall structure persists throughout the northern survey region.