From our searchlist of 54 we detected 41 galaxies. These HI profiles are shown in Fig. 1. Optical radial velocities of member galaxies (Hickson 1993) are indicated by vertical arrows and the corresponding identifying letter. The morphological types of these galaxies are given at the lower end of the arrows. In some cases HI- and optical velocities agree perfectly (e.g. HCG 4 , HCG 41). In many cases the identification between HI-profile and the corresponding galaxy is not possible due to confusion problems. Some profiles resemble the typical two-horned profiles of individual spiral galaxies while others look like strongly confused profiles because of the effect of the overlay of several profiles which are not safely separated in velocity space (e.g. HCG 40). Some of these profiles correspond to individual galaxies, indeed ; for HCG 41, HCG 78 there is only one galaxy within the velocity range searched for HI. Both these galaxies have 'normal' HI abundances (i.e. they are close to the solid line in Fig. 2). In a few cases the separation of HI-profiles allows tentative identification of individual HI-profiles with galaxies (e.g. HCG 4, HCG 14, and HCG 78).
In Table 1 we present the observational data: the HCG number in column 1, R.A. and Dec.(1950.0) in column 2, the optical redshift in column 3, a rough morphological description giving the total number of spirals and the total number N of galaxies in the brightest three magnitudes in column 4, the integrated blue luminosity of all member galaxies later than type E within the velocity interval searched for HI (column 5). The HI data follow; the measured HI flux (column 6), the observed peak of the line and its rms error in column 7 (for non detections only the rms noise is shown), the heliocentric radial velocity derived from the midpoint of the line at 25% and 20% of the peak and its error (column 8), and the linewidths at a level of 50%, 25%, and 20% of the line peak (column 9), and finally the relative HI-content of the group in column 10.
In Table 2 (which is only available in electronic form) we present a few derived parameter for the combined sample (i.e. data from Williams and Rood 1987 and from Table 1) : the HCG number (column 1), the 1950 position (column 2), the optical redshift (column 3), the heliocentric HI velocity (column 4) is followed by the assumed distance (column 5), the blue luminosity (column 6), the total HI-mass (column 7), and the ratio in column 8.
Velocity corrections to the centroid of the local group of galaxies have been made following de Vaucouleurs et al. (1990, RC3). Distances have been derived using a Hubble constant .
The total H I mass has been calculated by
where D is the distance in Mpc and is the integrated HI-flux in .
© European Southern Observatory (ESO) 1997
Online publication: April 28, 1998