The redshift-space two-point correlation function of ELAIS-S1 galaxies.

We investigate the clustering properties of galaxies in the recently completed ELAIS-S1 redshift survey through their spatial two-point autocorrelation function. We used a subsample of the ELAIS-S1 catalogue covering approximately 4 deg2 and consisting of 148 objects selected at 15μm with a flux>0.5 mJy and a redshift. We detected a positive signal in the correlation function that in the range of separationsis well approximated by a power law with a slopeand a correlation length, at the 90 per cent significance level. This result is in good agreement with the redshift-space correlation function measured in more local samples of mid-infrared-selected galaxies such as theIRASPoint Source Catalog (PSCz) redshift survey. This suggests a lack of significant clustering evolution of infrared-selected objects out tothat is further confirmed by the consistency found between the correlation functions measured in a localand a distantsubsample of ELAIS-S1 galaxies. We also confirm that optically selected galaxies in the local redshift surveys, especially those of the SDSS sample, are significantly more clustered than infrared objects. [ABSTRACT FROM AUTHOR]