Photometric redshifts

The COSMOS2015 photo-z catalogue

(Laigle et al. 2016)

Available here. The photometric redshifts and stellar masses are derived using “Le Phare” with a χ2 template-fitting method. The method to derive the photo-z is the same as Ilbert et al. (2013). Using the unique spectroscopic redshift sample in the COSMOS field we measure a photo-z accuracy of 0.007 and less than 0.5% of catastrophic failures by comparison with the zCOSMOS bright sample (Lilly et al. 2007), and a photo-z accuracy of 0.028 at 3 < z <  6. The deepest regions reach a 90% completeness limit of 1010 solar Mass to z =4. The set of filter transmission curves used for photometric fitting can be downloaded here.

The i-band selected photo-z catalogue

(Ilbert et al. 2009)

Available here. The photometric redshifts are derived using “Le Phare” with a χ2 template-fitting method. The method to derive the photo-z is fully described in Ilbert et al. (2009): we adopt several attenuation curves, include emission lines in the templates.  We obtained a photo-z accuracy better than 1% at z<1.4 for bright galaxies. Since the catalogue is i-selected, you can use it to create large samples of star-forming galaxies at high redshift. It should be noted that a NIR detection is not imposed in this catalogue, which increases the risk of catastrophic failures at z>1.5 and inacurated masses. A NIR-selected sample is also available.

The NIR-selected photo-z catalogue 

(Ilbert et al. 2013)

Available here. The method to compute the photometric redshifts and their quality is described in Ilbert et al. (2013). By construction, the sources are detected in NIR which guarantees a better accuracy on the photo-z at z>1.4. This catalogue should be used in order to create mass-limited samples at z > 1 since numerous sources may not be detected in optical (and then these sources will be missed in the i-selected catalogue).

Photometric redshifts for X-ray sources 

(Salvato et al. 2009, Salvato et al. 2011)

Photometric redshifts for Chandra and XMM-Newton selected sources were computed via SED fitting using a library of ad hoc constructed hybrid templates, also taking into account optical variability and morphology, and X-ray flux. All the details of the work are described in Salvato et al 2009 and 2011. Templates are publicly released and P(z) are also available, under request.

Available at:


For further information regarding the photometric redshift catalogues, please contact Olivier Ilbert - olivier.ilbert [at] ; Clotilde Laigle - laigle [at] ; Henry McCracken - h.j.mccracken [at] ; Peter Capak - capak [at] ; Mara Salvato - mara [at]