Galaxy formation and evolution at redshifts z>1

The FourStar Galaxy Evolution Survey (ZFOURGE) is a large and deep medium-band imaging survey aimed at establishing an observational benchmark of galaxy properties at redshift z > 1. ZFOURGE survey is carried out using an extremely efficient near-infrared FOURSTAR instrument on the Magellan telescope, in three HST legacy fields: COSMOS, CDFS, and UDS.

Accurate redshifts for ~60,000 galaxies at z>1

Most normal L* galaxies at 1 < z < 3 are too faint for spectroscopic observations, which has forced us to rely on inaccurate broadband photometric redshifts in the past. In response, we have equipped FourStar with innovative “medium-bandwidth” filters from 1 − 1.8μm (see Figure), which enable accurate and robust redshifts with ~2% accuracy for ~60,000 galaxies.

This GIF shows the increased sampling of a galaxy SED (C: Adam Tomczak).

We greatly acknowledge support from the Carnegie Observatories and the staff at the Las Campanas observatories during this survey.