During the last years we carried out 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. This work is the Ph.D. thesis of Victor Villar.

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 erg s^-1. 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_-0.03 M_solar yr^-1 Mpc^-3. 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.

The results of this work were published in the following paper:

The Hα-based Star Formation Rate Density of the Universe at z=0.84

For information about the follow-up spectroscopy in the rear infrared visit

• nIR spectroscopy of Hα galaxies at z=0.8