Star formation at z = 1.47 from HiZELS: An Hα+[OII] double-blind study?

This paper presents the results from the first wide and deep dual narrow-band survey to select Hα and [OII] line emitters at z = 1.47 ± 0.02, exploiting synergies between the United Kingdom InfraRed Telescope and the Subaru telescope by using matched narrow-band filters in the H and z ′ bands. The Hα survey at z = 1.47 reaches a 3σ flux limit of FHα ≈ 7 × 10−17 erg s−1 cm−2 (corresponding to a limiting SFR in Hα of ≈ 7M yr−1) and detects ≈ 200 Hα emitters over 0.7 deg2, while the much deeper [OII] survey reaches an effective flux of ≈ 7×10−18 erg s−1 cm−2 (SFR in [OII] of ∼ 1 M yr−1), detecting ≈ 1400 z = 1.47 [OII] emitters in a matched co-moving volume of ∼ 2.5 × 105 Mpc3. The combined survey results in the identification of 190 simultaneous Hα and [OII] emitters at z = 1.47. Hα and [OII] luminosity functions are derived and both are shown to evolve significantly from z ∼ 0 in a consistent way. The star formation rate density of the Universe at z = 1.47 is evaluated, with the Hα analysis yielding ρSFR = 0.16 ± 0.05M yr−1 Mpc−3 and the [OII] analysis ρSFR = 0.17 ± 0.04M yr−1 Mpc−3. The measurements are combined with other studies, providing a self-consistent measurement of the star formation history of the Univers