A 20 deg2 deep Subaru Hyper-SuprimeCam imaging & Keck LRIS + MOSFIRE spectroscopic survey of the two primary Euclid Deep Calibration Fields (NEP and CDFS).

*** Requested Observations for S19B ***

4 (+1) nights Subaru HSC & 3 (+2) nights Keck II DEIMOS


The twin Keck Observatory telescopes are among the world’s most scientifically productive optical and infrared telescopes.

Subaru HSC

Subary Telescope is the 8.2-meter (320 in) flagship telescope of the National Astronomical Observatory of Japan located at the Maunakea Observatory on Hawaii .


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. 

Science Goals

Galaxy Evolution

Probe the assembly of massive galaxies by tracing the evolution of their stellar mass function with >500,000 galaxies at 3 < z < 6 and including several thousand at z > 6.

Stellar Mass Functions

Link the stellar mass of galaxies to their dark matter halos via clustering, for testing of cosmological models.

Dark Energy

Constrain the properties of dark energy using the non-linear power spectrum at high-redshift.

Galaxy Formation

Identify the earliest sites of galaxy formation and reionization, and spectroscopically confirm high-escape fraction candidates.

Quenching in the Early Universe

Identify and confirm the first galaxies to quench their star formation.

Institute for Astronomy

We are one of the largest university astronomy programs in the world.