A Public Ks-selected Catalog in the COSMOS/UltraVISTA Field: Photometry, Photometric Redshifts and Stellar Population Parameters

TL;DR

This paper presents a comprehensive multi-wavelength catalog of galaxies in the COSMOS/UltraVISTA field, including photometry, redshifts, and stellar parameters, enabling detailed studies of galaxy evolution up to redshift 4.

Contribution

The catalog combines PSF-matched photometry across 30 bands with accurate photometric redshifts and stellar parameters, covering a large area with unprecedented depth and wavelength coverage.

Findings

Photometric redshifts are accurate to dz/(1+z)=0.013 up to z~1.5.

Galaxy bi-modality is confirmed out to z~2.

Star-forming main sequence evolves consistently with previous studies.

Abstract

We present a catalog covering 1.62 deg^2 of the COSMOS/UltraVISTA field with PSF-matched photometry in 30 photometric bands. The catalog covers the wavelength range 0.15um - 24um including the available GALEX, Subaru, CFHT, VISTA and Spitzer data. Catalog sources have been selected from the DR1 UltraVISTA Ks band imaging that reaches a depth of K_{s,tot} = 23.4 AB (90% completeness). The PSF-matched catalog is generated using position-dependent PSFs ensuring accurate colors across the entire field. Also included is a catalog of photometric redshifts (z_phot) for all galaxies computed with the EAZY code. Comparison with spectroscopy from the zCOSMOS 10k bright sample shows that up to z ~ 1.5 the z_phot are accurate to dz/(1 + z) = 0.013, with a catastrophic outlier fraction of only 1.6%. The z_phot also show good agreement with the z_phot from the NEWFIRM Medium Band Survey (NMBS) out to z ~ 3. A catalog of stellar masses and stellar population parameters for galaxies determined using the FAST spectral energy distribution fitting code is provided for all galaxies. Also included are rest-frame U-V and V-J colors, L_2800 and L_IR. The UVJ color-color diagram confirms that the galaxy bi-modality is well-established out to z ~ 2. Star-forming galaxies also obey a star forming "main sequence" out to z ~ 2.5, and this sequence evolves in a manner consistent with previous measurements. The COSMOS/UltraVISTA Ks-selected catalog covers a unique parameter space in both depth, area, and multi-wavelength coverage and promises to be a useful tool for studying the growth of the galaxy population out to z ~ 3 - 4.