Redshift Measures
Radial velocities were measured using procedures based on the Fourier cross-correlation method, as implemented in the xcsao task in the RVSAO package. RVSAO is an IRAF add-on package developed at the Smithsonian Astrophysical Observatory Telescope Data Center to obtain radial velocities from spectra using cross-correlation and emission line fitting techniques. All the spectra were inspected by eye to verify the redshift measurements and to ensure that the best matching template was chosen. Finally we checked the spectra for possible residual shifts due to systematic errors in the wavelength calibration. Each radial velocity measurement was corrected to the heliocentric velocity. The following figure shows the redshift distribution of the whole spectroscopic sample.
An example catalogue can be seen in the table below. The different columns are: column (1) gives the object name, column (2) gives the right ascension (J2000), and column (3) gives the declination (J2000), column (4) gives the redshift, in km sec−1 , and column (5) the redshift error in km sec−1 , column (6) gives the correlation factor r (Only spectra achieving a correlation factor higher than 2 have been considered reliable after the visual check) Column (7) gives the membership flag; a value of 1 indicates the galaxy is a cluster member, and a value of 0 indicates it is either a background or foreground galaxy. Column (8) indicates the cluster field to which the galaxy belongs.
