SIMBAD references

We have carried out the largest (>3.5x10⁵ Mpc3, 26 deg2) Hα narrow-band survey to date at z ∼ 0.2 in the SA22, W2 and XMMLSS extragalactic fields. Our survey covers a large enough volume to overcome cosmic variance and to sample bright and rare Hα emitters up to an observed luminosity of ∼ 10^42.4 erg/s, equivalent to ∼ 11M_☉/yr. Using our sample of 220 sources brighter than >1041.4 erg/s (>1M_☉/yr), we derive Hα luminosity functions, which are well described by a Schechter function with φ* = 10^–2.85±0.03/Mpc3 and L^*_Hα = 10^41.71±0.02 erg/s (with a fixed faint end slope α = -1.35). We find that surveys probing smaller volumes ( ∼ 3x10⁴ Mpc3) are heavily affected by cosmic variance, which can lead to errors of over 100 per cent in the characteristic density and luminosity of the Hα luminosity function. We derive a star formation rate density of ρSFRD = 0.0094±0.0008M_☉/yr, in agreement with the redshift-dependent Hα parametrization from Sobral et al. The two-point correlation function is described by a single power law ω(θ) = (0.159±0.012)θ(-0.75±0.05), corresponding to a clustering length of r0 = 3.3±0.8 Mpc h-1. We find that the most luminous Hα emitters at z ∼ 0.2 are more strongly clustered than the relatively fainter ones. The L^*_Hα Hα emitters at z ∼ 0.2 in our sample reside in ∼ 10^12.5-13.5_☉ dark matter haloes. This implies that the most star-forming galaxies always reside in relatively massive haloes or group-like environments and that the typical host halo mass of star-forming galaxies is independent of redshift if scaled by L_Hα/L^*_Hα(z), as proposed by Sobral et al.