2008ApJ...677..169V

We present the results of an Hα near-infrared narrowband survey searching for star-forming galaxies at redshift z=0.84. This work is an extension of our previous narrowband studies in the optical at lower redshifts. After removal of stars and redshift interlopers (using spectroscopic and photometric redshifts), we build a complete sample of 165 Hα emitters in the extended Groth strip and GOODS-N fields with L(Hα)>10⁴¹ ergs/s. We compute the Hα luminosity function at z=0.84 after corrections for [N II] flux contamination, extinction, systematic errors, and incompleteness. Our sources present an average dust extinction of A(Hα)=1.5 mag. Adopting Hα as a surrogate for the instantaneous SFR, we measure an extinction-corrected SFR density of 0.17^+0.03_–0.03M_☉/yr/Mpc3. Combining this result to our prior measurements at z=0.02, 0.24, and 0.40, we derive an Hα-based evolution of the SFR density proportional to (1+z)^β with β=3.8±0.5. This evolution is consistent with that derived by other authors using different SFR tracers.