Hawaii Two-0 Science
High-Redshift Dropout Galaxies
To provide estimates for the ultimate outcomes of the H20 survey, we have identified a sample of high-redshift galaxies using available ultra-deep (limiting mag. ≥27) HSC data in the COSMOS Deep Field. “Dropout” galaxies were selected using standard Lyman break galaxy color selection criteria based on the analysis of Ono et al. (2018). At the conclusion of the H20 observing program, we expect to have a final sample of:
COSMOS 2 sq. deg
H20 20 sq. deg
2,00,000+ galaxies @ z~3
3,00,000+ galaxies @ z~2
Testing New Statistics for Cosmological Measurements
One of the difficulties of extracting cosmological information from galaxy surveys (including the upcoming Euclid and WFIRST missions) is the fact that galaxies are biased tracers of dark matter. Unfortunately, current bias models focus primarily on high-density regions, whereas low-density regions carry significant amounts of information relevant to the constraint of dark energy and alternative gravity theories. For this reason, proper treatment of both high and low densities is important for future surveys. We have developed an interactionless Ising model for this bias (Repp & Szapudi, in prep.) which exhibits a remarkably good fit to both Millennium Simulation and Sloan Digital Sky Survey data, at both density extremes. We intend to test this model against a variety of other galaxy catalogs, one of which will be that produced by Hawaii 2-0. Obtaining spectroscopic redshifts for dropouts will in particular allow us to test our prescription against the data at multiple high redshifts, thus investigating, first, whether the model is accurate at these redshifts and, second, how the bias has evolved with cosmic time.
Galaxy Two-Point Correlation Function and Galaxy-Dark Matter Bias
Using high-redshift dropout sources in the COSMOS (comparable to the ultimate depth of the H20 survey), we have made preliminary measurements of the galaxyspherical angular two-point point correlation function. Comparison of these measurements with predictions from cosmological provides the ability to constrain the Galaxy-Dark Matter bias — a key cosmological observable — which quantifies the offset between the two-point correlation function of galaxies and dark matter (see Figure at right).