The FourStar galaxy evolution survey ( ZFOURGE ) is a 45 night legacy program with the FourStar near-infrared camera on Magellan and one of the most sensitive surveys to date .
ZFOURGE covers a total of 400 \mathrm { arcmin } ^ { 2 } in cosmic fields CDFS , COSMOS and UDS , overlapping CANDELS .
We present photometric catalogs comprising > 70 , 000 galaxies , selected from ultradeep K _ { s } -band detection images ( 25.5 - 26.5 AB mag , 5 \sigma , total ) , and > 80 \% complete to K _ { s } < 25.3 - 25.9 AB .
We use 5 near-IR medium-bandwidth filters ( J _ { 1 } ,J _ { 2 } ,J _ { 3 } ,H _ { s } ,H _ { l } ) as well as broad-band K _ { s } at 1.05 -2.16 \micron to 25 - 26 AB at a seeing of \sim 0 \farcs 5 .
Each field has ancillary imaging in 26 - 40 filters at 0.3 - 8 \micron .
We derive photometric redshifts and stellar population properties .
Comparing with spectroscopic redshifts indicates a photometric redshift uncertainty \sigma _ { z } = { 0.010 , 0.009 } , and 0.011 in CDFS , COSMOS , and UDS .
As spectroscopic samples are often biased towards bright and blue sources , we also inspect the photometric redshift differences between close pairs of galaxies , finding \sigma _ { z,pairs } = 0.01 - 0.02 at 1 < z < 2.5 .
We quantify how \sigma _ { z,pairs } depends on redshift , magnitude , SED type , and the inclusion of FourStar medium bands . \sigma _ { z,pairs } is smallest for bright , blue star-forming samples , while red star-forming galaxies have the worst \sigma _ { z,pairs } .
Including FourStar medium bands reduces \sigma _ { z,pairs } by 50 % at 1.5 < z < 2.5 .
We calculate SFRs based on ultraviolet and ultradeep far-IR Spitzer /MIPS and Herschel/PACS data .
We derive rest-frame U - V and V - J colors , and illustrate how these correlate with specific SFR and dust emission to z = 3.5 .
We confirm the existence of quiescent galaxies at z \sim 3 , demonstrating their SFRs are suppressed by > \times 15 .