We present the COSMOS2015 a catalog which contains precise photometric redshifts and stellar masses for more than half a million objects over the 2deg 2 COSMOS field. Including new Y JHK s images from the UltraVISTA-DR2 survey, Y -band from Subaru/Hyper-Suprime-Cam and infrared data from the Spitzer Large Area Survey with the Hyper-Suprime-Cam Spitzer legacy program, this near-infraredselected catalog is highly optimized 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 a χ 2 sum of the Y JHK s and z ++ images. The catalog contains ∼ 6 × 10 5 objects in the 1.5 deg 2 UltraVISTA-DR2 region, and ∼ 1.5 × 10 5 objects are detected in the "ultra-deep stripes" (0.62 deg 2 ) at K s ≤ 24.7 (3σ, 3 , AB magnitude). Through a comparison with the zCOSMOSbright spectroscopic redshifts, we measure a photometric redshift precision of σ ∆z/(1+zs) = 0.007 and a catastrophic failure fraction of η = 0.5%. At 3 < z < 6, using the unique database of spectroscopic redshifts in COSMOS, we find σ ∆z/(1+zs) = 0.021 and η = 13.2%. The deepest regions reach a 90% completeness limit of 10 10 M to z = 4. Detailed comparisons of the color distributions, number counts, and clustering show excellent agreement with the literature in the same mass ranges. COSMOS2015 represents a unique, publicly available, valuable resource with which to investigate the evolution of galaxies within their environment back to the earliest stages of the history of the Universe. The COSMOS2015 catalog is distributed via anonymous ftp b and through the usual astronomical archive systems (CDS, ESO, IRSA).

We present accurate photometric redshifts in the 2-deg 2 COSMOS field. The redshifts are computed with 30 broad, intermediate, and narrow bands covering the UV (GALEX), Visible-NIR (Subaru, CFHT, UKIRT and NOAO) and mid-IR (Spitzer/IRAC). A χ 2 template-fitting method (Le Phare) was used and calibrated with large spectroscopic samples from VLT-VIMOS and Keck-DEIMOS. We develop and implement a new method which accounts for the contributions from emission lines ([O II], Hβ, Hα and Lyα) to the spectral energy distributions (SEDs). The treatment of emission lines improves the photo-z accuracy by a factor of 2.5. Comparison of the derived photo-z with 4148 spectroscopic redshifts (i.e. ∆z = z s − z p ) indicates a dispersion of σ ∆z/(1+zs) = 0.007 at i + AB < 22.5, a factor of 2 − 6 times more accurate than earlier photo-z in the COSMOS, CFHTLS and COMBO-17 survey fields. At fainter magnitudes i + AB < 24 and z < 1.25, the accuracy is σ ∆z/(1+zs) = 0.012. The deep NIR and IRAC coverage enables the photo-z to be extended to z ∼ 2 albeit with a lower accuracy (σ ∆z/(1+zs) = 0.06 at i + AB ∼ 24). The redshift distribution of large magnitude-selected samples is derived and the median redshift is found to range from z m = 0.66 at 22 < i + AB < 22.5 to z m = 1.06 at 24.5 < i + AB < 25. At i + AB < 26.0, the multi-wavelength COSMOS catalog includes approximately 607,617 objects. The COSMOS-30 photo-z enable the full exploitation of this survey for studies of galaxy and large scale structure evolution at high redshift.