GLOBAL STAR FORMATION RATE DENSITY OVER 0.7 < z < 1.9

We determine the global star formation rate (SFR) density at 0.7 < z < 1.9 using emission-line-selected galaxies identified in Hubble Space Telescope-Near Infrared Camera and Multi-Object Spectrograph (HST-NICMOS) grism spectroscopy observations. Observing in a pure parallel mode throughout HST Cycles 12 and 13, our survey covers {approx}104 arcmin{sup 2} from which we select 80 galaxies with likely redshifted H{alpha} emission lines. In several cases, a somewhat weaker [O III] doublet emission is also detected. The H{alpha} luminosity range of the emission-line galaxy sample is 4.4 x 10{sup 41} < L(H{alpha}) < 1.5 x 10{sup 43} erg s{sup -1}. In this range, the luminosity function is well described by a Schechter function with {phi}* = (4.24 {+-} 3.55) x 10{sup -3} Mpc{sup -3}, L* = (2.88 {+-} 1.58) x 10{sup 42} erg s{sup -1}, and {alpha} = -1.39 {+-} 0.43. We derive a volume-averaged SFR density of 0.138 {+-} 0.058 M {sub sun} yr{sup -1} Mpc{sup -3} at z = 1.4 without an extinction correction. Subdividing the redshift range, we find SFR densities of 0.088 {+-} 0.056 M {sub sun} yr{sup -1} Mpc{sup -3} at z = 1.1 and 0.265 {+-} 0.174 M {sub sun} yr{sup -1} Mpc{sup -3} at z = 1.6. The overall star formation rate density is consistent with previous studies using H{alpha} when the same average extinction correction is applied, confirming that the cosmic peak of star formation occurs at z > 1.5.