Clustering-based redshift estimation: Application to VIPERS/CFHTLS

Scottez, V; Mellier, Y.; Granett, B. R.; Moutard, T.; Kilbinger, M.; Scodeggio, M.; Garilli, B.; Bolzonella, M.; de la Torre, S.; Guzzo, L.; Abbas, U.; Adami, C.; Arnouts, S.; Bottini, D.; Branchini, ENZO FRANCO; Cappi, A.; Cucciati, O.; Davidzon, I.; Fritz, A.; Franzetti, P.; Iovino, A.; Krywult, J.; Le Brun, V.; Le Fèvre, O.; Maccagni, D.; Malek, K.; Marulli, F.; Polletta, M.; Pollo, A.; Tasca, L. A. M.; Tojeiro, R.; Vergani, D.; Zanichelli, A.; Bel, J.; Coupon, J.; De Lucia, G.; Ilbert, O.; Mccracken, H. J.; Moscardini, L.

doi:10.1093/mnras/stw1500

We explore the accuracy of the clustering-based redshift estimation proposed by Ménard et al. when applied to VIMOS Public Extragalactic Redshift Survey (VIPERS) and Canada- France-Hawaii Telescope Legacy Survey (CFHTLS) real data. This method enables us to reconstruct redshift distributions from measurement of the angular clustering of objects using a set of secure spectroscopic redshifts. We use state-of-the-art spectroscopic measurements with iAB < 22.5 from the VIPERS as reference population to infer the redshift distribution of galaxies from the CFHTLS T0007 release. VIPERS provides a nearly representative sample to a flux limit of iAB < 22.5 at a redshift of > 0.5 which allows us to test the accuracy of the clustering-based redshift distributions. We show that this method enables us to reproduce the true mean colour-redshift relation when both populations have the same magnitude limit. We also show that this technique allows the inference of redshift distributions for a population fainter than the reference and we give an estimate of the colour-redshift mapping in this case. This last point is of great interest for future large-redshift surveys which require a complete faint spectroscopic sample.

Clustering-based redshift estimation: Application to VIPERS/CFHTLS

Scottez, V;Mellier, Y.;Granett, B. R.;Moutard, T.;Kilbinger, M.;Scodeggio, M.;Garilli, B.;Bolzonella, M.;de la Torre, S.;Guzzo, L.;Abbas, U.;Adami, C.;Arnouts, S.;Bottini, D.;BRANCHINI, ENZO FRANCO;Cappi, A.;Cucciati, O.;Davidzon, I.;Fritz, A.;Franzetti, P.;Iovino, A.;Krywult, J.;Le Brun, V.;Le Fèvre, O.;Maccagni, D.;Malek, K.;Marulli, F.;Polletta, M.;Pollo, A.;Tasca, L. A. M.;Tojeiro, R.;Vergani, D.;Zanichelli, A.;Bel, J.;Coupon, J.;De Lucia, G.;Ilbert, O.;Mccracken, H. J.;Moscardini, L.

2016-01-01

Abstract

We explore the accuracy of the clustering-based redshift estimation proposed by Ménard et al. when applied to VIMOS Public Extragalactic Redshift Survey (VIPERS) and Canada- France-Hawaii Telescope Legacy Survey (CFHTLS) real data. This method enables us to reconstruct redshift distributions from measurement of the angular clustering of objects using a set of secure spectroscopic redshifts. We use state-of-the-art spectroscopic measurements with iAB < 22.5 from the VIPERS as reference population to infer the redshift distribution of galaxies from the CFHTLS T0007 release. VIPERS provides a nearly representative sample to a flux limit of iAB < 22.5 at a redshift of > 0.5 which allows us to test the accuracy of the clustering-based redshift distributions. We show that this method enables us to reproduce the true mean colour-redshift relation when both populations have the same magnitude limit. We also show that this technique allows the inference of redshift distributions for a population fainter than the reference and we give an estimate of the colour-redshift mapping in this case. This last point is of great interest for future large-redshift surveys which require a complete faint spectroscopic sample.