Photometry

COSMOS2015

(Laigle et al. 2016)

Available here. The COSMOS2015 catalogue contains precise PSF-matched photometry, photometric redshifts and stellar masses for more than half a million of sources (excluding masked area) on the COSMOS field. Including all the already existing optical bands, new YJHKimages from the UltraVISTA-DR2 survey, Y -band from Hyper Suprime-Cam and infrared data from SPLASH Spitzer legacy program, this near-infrared selected catalog is highly optimised for the study of galaxy evolution and environments in the early Universe. To maximise catalog completeness for bluer objects and at higher redshifts, objects have been detected on an ultra-deep chi-squared sum of the YJHKand z++ images by running SExtractor in dual mode (Bertin & Arnouts 1996). The catalog contains  6 × 105 objects in the 1.5 deg2 UltraVISTA-DR2 area and  1.5×105 in the “ultra-deep stripes” (0.62 deg2) at K≤ 24.7 (3σ,3′′). The deepest regions reach a 90% completeness limit of 1010M to z = 4. Detailed comparisons of the colour distributions, number counts and clustering show excellent agreement with the literature in the mass ranges where these studies overlap with ours. The COSMOS2015 catalogue represents an invaluable public resource to investigate the evolution of galaxies within their environment back to the earliest stages of the history of the Universe. This catalogue can be downloaded via anonymous FTP and is fully described in Laigle et al. (2016).

The i-band selected catalogue v2.1

(Capak et al. 2007, Ilbert et al. 2009)

Available here. This catalogue contains 2 million sources selected in i+ band. The method to create the i-band selected catalogue is described in Capak et al. (2007).  Since 2007, this catalogue has continuously been improved by adding new datasets. We are currently releasing version v2.1 of this catalogue including the medium-band data from Subaru, the UltraVISTA data, the SPLASH data which did not existing in 2007. Still, the method to generate the multi-color catalogue remains the same. Photometry was done using SExtractor in dual mode (Bertin & Arnouts 1996). Source detection was run on the deepest image (i+ ~26.2 for a point source detected at 5σ). In order to obtain accurate colors, all the images were degraded to the same PSF of 1.5”. The final photometric catalogue contains PSF matched photometry for all the bands from the u∗ to the K band, measured over an aperture of 3” diameter at the position of the i+ band detection.  For the FUV and NUV GALEX data, the catalogue is provided in total flux obtained by a PSF fitting procedure (Zamojski et al. 2007). The IRAC fluxes were measured in a circular aperture of radius 1.9” and converted to a total flux using aperture corrections.

 

The NIR-selected catalogue

(McCracken et al. 2012, Ilbert et al. 2013)

Available hereA NIR-selected catalogue has been produced by McCracken et al. (2012). In this catalogue, the detection image is the chi-squared sum of the (non-convolved) UltraVISTA DR1 YJHKs images, following the techniques outlined in Szalay et al. (1999). The method to generate this catalogue is almost the same as Capak et al. (2007). The main difference is that the images were degraded to the same PSF of 1.1”, rather than 1.5” (because we decided to drop the g band from our analysis).

Contact

If you require further information on these photometric catalogues, please contact Clotilde Laigle - laigle [at] iap.fr ; Olivier Ilbert - olivier.ilbert [at] lam.fr ; Henry McCracken - h.j.mccracken [at] gmail.com ; Peter Capak - capak [at] astro.caltech.edu