Galaxy And Mass Assembly (GAMA): Curation and reanalysis of 17.5k redshifts in the G10/COSMOS region
We discuss the construction of the Galaxy And Mass Assembly (GAMA) 10h region (G10) using publicly available data in the Cosmic Evolution Survey region (COSMOS) in order to extend the GAMA survey to z~1 in a single ~1deg$^2$. In order to obtain the maximum number of high precision spectroscopic redshifts we re-reduce all archival zCOSMOS-bright data and use the GAMA automatic cross-correlation redshift fitting code autoz. We combine autoz redshifts with all other available redshift information (zCOSMOS-bright 10k, PRIMUS, VVDS, SDSS and photometric redshifts) to calculate robust best-fit redshifts for all galaxies and visually inspect all 1D and 2D spectra to confirm automatically assigned redshifts. In total, we obtain 17,466 robust redshifts in the full COSMOS region. We then define the G10 region to be the central ~1deg$^2$ of COSMOS, which has relatively high spectroscopic completeness, and encompasses the CHILES VLA region. We define a combined r < 23.0 mag & i < 22.0 mag G10 sample (selected to have the highest bijective overlap) with which to perform future analysis. The G10 sample contains 10,247 sources with reliable high precision VLT-VIMOS spectra – with a median redshift of 0.55 and ~53% completeness to all non-stellar r < 23 mag & i < 22.0 mag sources, we define this to be the G10-HR sample. We also produce a full spectroscopic sample (G10-ALL) which contains a further 2,504 r < 23 mag & i < 22.0 mag galaxies with lower precision PRIMUS spectroscopy – sufficient for all GAMA-type analyses other than group finding. In total the G10- ALL sample contains 12,751 galaxies with reliable redshifts and is ~66% complete to r < 23 mag & i < 22.0 mag. All tables and spectra are released through the G10 cutout tool at: http://ict.icrar.org/cutout/G10.