Science - Overview

Measuring accurate Stellar Mass Functions. A simulation of the stellar mass function measurements using existing Spitzer data (black) and the new SPLASH data (red). SPLASH increases the number of objects with mass estimates by an order of magnitude at z > 4. This enables the measurement of stellar mass functions at high redshift. Especially we improve the high-mass ends due to the large area of COSMOS.

Exploring the Large Scale Structure. A simulation of the distribution of IRAC detected galaxies at 4 < z < 5 (gray points) for the area and depth of the existing data (left) and the SPLASH (right). Progenitors of modern day galaxy clusters are marked in red. The largest existing deep continuous Spitzer field is indicated as a black box. The area covered by SPLASH is shown as circle. SPLASH enables us to detect high-‐redshift large-‐ scale structure extending over several Mpc.

Improvement of Photometric Redshifts. Simulation showing the improvement in derived photometric redshifts with SPLASH based on the actual distribution of galaxies in COSMOS. At 3 < z < 6 the outlier fraction decreases from 23% to 7%. This allows us to establish accurate stellar mass functions as well as allows us to probe large-‐scale structure at z > 3.

Search for Transients. SPLASH enables the search of transients. The number of super-luminous supernovae at high redshifts allows us to constrain the high mass end slope of the initial mass function.

Improvement of Stellar Masses. The depth of mid-IR measurements enabled by SPLASH allows the improvement of stellar mass estimates at z > 4. Furthermore, the IRAC colors enable us to access the contamination of broad-‐band filters by strong optical emission lines expected in high-z galaxies.