6 Description of the catalogue

The catalogue of 660 galaxies in a field of about 10 square degrees is available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html. In this section, we give detailed information on the structure and the content of the catalogue:

Column (1) Running number.

Column (2) Cross-identification, taken from NED or PGC (Paturel et al. [1989], [1993]). Only the most common name is given, i.e. NGC, IC, UGC, PGC number, or NED object name (in this order). The cross-identification is primarily based on positions. For positional differences <4'' we assume that the corresponding galaxies are identical. For differences from 4'' to 60'' cross-identifications are given only if (a) the positions agree within the given error boxes and (b) any misidentification can be ruled out. A few UGC galaxies with larger positional errors could be identified as well.

Column (3) Right ascension $\alpha$ for equinox 2000, in hours, minutes, and seconds. The mean error is $\sim0\hbox{$.\!\!^{\rm s}$}03$.

Column (4) Declination $\delta$ for equinox 2000, in degrees, arcminutes, and arcseconds. The mean error is $0\hbox{$.\!\!^{\prime\prime}$}3$.

Column (5) Apparent magnitude B₂₅ within a limiting isophote of $\mu_B=25$magarcsec^-2. No corrections regarding Galactic extinction, inclination and K-dimming have been applied. Due to image crowding by galaxies and foreground stars the mean uncertainty is about 0.1 to 0.2mag. Larger uncertainties due to difficulties in the removal of foreground stars are marked by a colon.

Column (6) Central B-surface brightness $\mu_{\rm C}$ determined from the central 5arcsec² of the galaxy, in magarcsec^-2.

Column (7) Major axis a of an ellipse fitted on the $\mu_B=25$magarcsec^-2 isophote, in arcsec. The mean error is less than 10%.

Column (8) Minor axis b of an ellipse fitted on the $\mu_B=25$magarcsec^-2 isophote, in arcsec. The mean error is less than 10%.

Column (9) Position angle PA, in degrees East of North. The accuracy depends on the ellipticity; usually the given PAs agree within a few degrees with the PGC data.

Column (10) Heliocentric radial velocity $v_{\rm rad}$,in kms^-1. For 166 galaxies, radial velocity data have been available either from the NED or from the PGC, respectively. For the galaxies 329, 335, 342, 353, and 540, radial velocities have been determined in the present study (see Sect. 4.3).

Column (11) Morphological type class (see Sect. 5).

Column (12) Remarks. If the estimation of the morphological type is hampered by a nearby foreground star this is indicated by "f$\ast$''. Morphological peculiarities are coded as DIS, IN, CH, PL (Sect.5.3) with strength indicated by "+'' (strong) or "-'' (weak). If other galaxies from the catalogue are related to the mentioned peculiarity, their catalogue numbers are given in brackets.