We propose the Hawaii Two-0 (H20) survey, which will help to put Hawaii at the forefront of galaxy evolution studies for the next decade or more. This will be achieved by carrying out a 20 deg2 deep Subaru Hyper-SuprimeCam (HSC) imaging and Keck DEIMOS + MOSFIRE spectroscopic survey of the two primary Euclid Deep Calibration Fields (NEP and CDFS). These two 10 deg2 fields are the targets of the largest allocation of Spitzer time ever granted (~5300h) and will be the targets of ultra-deep 1-2 μm photometry and spectroscopy by the Euclid mission scheduled to launch in early 2021. The H20 data will permit immediate science investigations at z < 7 using the HSC+Spitzer data and will give Hawaii priority for z > 7 science once Euclid launches.
The proposed program spans 3 years (6 semesters). The first two years consists of 30 nights of HSC (grizy) imaging to cover both fields. In the final year of the program we request 5 nights of Keck-DEIMOS and 5 nights of Keck-MOSFIRE time to obtain spectroscopy of high-redshift sources selected from the Imaging Survey. The spectroscopy will be critical for verifying the photometric redshifts, for characterizing rare and interesting sources, and for selecting targets for follow-up with ALMA and JWST. The combined HSC+Spitzer imaging data will provide the largest and only cosmologically significant sample of z > 3 galaxies with stellar mass estimates for at least the next decade. These data will allow us to provide the first definitive constraint on the evolution of massive (M/M⊙ > 1010.5) galaxies at 3 < z < 7, estimate the properties of their dark matter haloes through clustering measurements, and find rare “Rosetta stone” objects that are re-ionzing the universe during this key epoch of galaxy evolution.
The Keck spectroscopy will also be used to confirm redshifts and characterize rare/interesting objects, proto-clusters, and quasars as well as measure the strength of the Ly-α, [Oii], and other lines to search for high-escape fraction objects. In addition, any remaining open slits on the masks will be used to obtain spectra for a fully representative sample of galaxies at 3 < z < 7 using methods previously pioneered by members of our group. The H20 Survey will allow all Hawaii graduate students, a TBD Hawaii postdoc, and the Hawaii PIs of this project immediate access to Euclid 0.5-2 μm data when the mission starts in early 2021 (immediately following the completion date of H20). At that point, a set of unprecedented z > 7 galaxy studies will start, with Hawaii having priority for this science based on the data obtained in the H2O Survey.