The "Virgo photometry catalogue”; a catalogue of 1180 galaxies in the direction of the Virgo Cluster's core

Abstract

We present a new catalogue of galaxies in the direction of the Virgo Cluster's core: the Virgo Photometry Catalogue (VPC) 1 . This catalogue contains 1180 galaxies (including background objects) within a 23 square-degree area of the sky centred on R:A:1950:0 = 12 h 26 m and dec:1950:0 =1 308 0 . The VPC galaxy sample comprises of non-stellar objects brighter thanBJ25 =1 9 :0; the completeness limits beingBJ25 18:5 for the northern half of the survey area and BJ25 18:0 for the southern half. Independently-calibrated photographic surface pho- tometry is presented for over 1000 galaxies in the U, BJ and RC bands. Parameters listed for catalogued galax- ies include: equatorial coordinates, morphological types, surface-brightness prole parameters (which preserve the majority of the original surface photometry information), U, BJ & RC isophotal magnitudes, BJ and (transformed) B total magnitudes, (U BJ )a nd ( B J R C) equal-area and total colours, apparent angular radii, ellipticities, po- sition angles, heliocentric radial velocities and alternative designations. All total magnitudes and total colours are extrapolated according to a new system denoted t in or- der to distinguish it from the T system already in use. The VPC is based primarily on four (one U ,t wo B J and one RC) UK-Schmidt plates, all of which were digi- tised using the Royal Observatory Edinburgh's (ROE) COSMOS measuring machine. All magnitudes, colours and surface-brightness parameters are derived from nu- merical integrations of segmented plate-scan data, except for (in 109 cases) saturated or (in 51 cases) inextricably-