Guenther HASINGER
(Institute for Astronomy, University of Hawaii)
I will report on the deepest optical images of the COSMOS field based on a joint dataset (Tanaka, Hasinger, Silverman et al., 2017) taken with Hyper Suprime-Cam (HSC) by the HSC Subaru Strategic Program (SSP) team and the University of Hawaii (UH). The coadded images reach impressive depths of g=27.8, r=27.7, i=27.6, z=26.8, and y=26.2 mag at 5 sigma for point sources and cover essentially the entire COSMOS 2 square degree field (and more). The seeing is between 0.6 and 0.9 arcsec on the coadded images. We perform several quality checks and confirm that the data are of excellent photometric (~2%)and astrometric (30 mas) quality. The new images are used in conjunction with several other new dataset to perform new multiwavelength identifications of some of the Chandra sources that did not have optical counterparts in the published catalogue (Marchesi et al., 2016).