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 15 μm with a flux >0.5 mJy and a redshift z < 0.5. We detected a positive signal in the correlation function that in the range of separations 1-10h-1 Mpc is well approximated by a power law with a slope γ= 1.4 +/- 0.25 and a correlation length s0= 5.4 +/- 1.2h-1 Mpc, 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 the IRAS Point Source Catalog (PSCz) redshift survey. This suggests a lack of significant clustering evolution of infrared-selected objects out to z= 0.5 that is further confirmed by the consistency found between the correlation functions measured in a local (z < 0.2) and a distant (0.2 < z < 0.5) subsample 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.
D'Elia, V., Branchini, E., La Franca, F., Baccetti, V., Matute, I., Pozzi, F., et al. (2005). The redshift-space two-point correlation function of ELAIS-S1 galaxies. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 359(3), 1077-1082 [10.1111/j.1365-2966.2005.08971.x].
The redshift-space two-point correlation function of ELAIS-S1 galaxies
Branchini E;La Franca F.;
2005-01-01
Abstract
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 15 μm with a flux >0.5 mJy and a redshift z < 0.5. We detected a positive signal in the correlation function that in the range of separations 1-10h-1 Mpc is well approximated by a power law with a slope γ= 1.4 +/- 0.25 and a correlation length s0= 5.4 +/- 1.2h-1 Mpc, 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 the IRAS Point Source Catalog (PSCz) redshift survey. This suggests a lack of significant clustering evolution of infrared-selected objects out to z= 0.5 that is further confirmed by the consistency found between the correlation functions measured in a local (z < 0.2) and a distant (0.2 < z < 0.5) subsample 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
