CF-HiZELS, an ∼10 deg2 emission-line survey with spectroscopic follow-up: Hα, [O iii] + Hβ and [O ii] luminosity functions at z = 0.8, 1.4 and 2.2

Sobral, D.; Matthee, J.; Best, P.N.; Smail, I.; Khostovan, A.A.; Milvang-Jensen, B.; Kim, J.-W.; Stott, J.; Calhau, J.; Nayyeri, H.; Mobasher, B.

Abstract

We present results from the largest contiguous narrow-band survey in the near-infrared. We have used the wide-field infrared camera/Canada–France–Hawaii Telescope and the lowOH2 filter (1.187 ± 0.005 μm) to survey ≈10 deg2 of contiguous extragalactic sky in the SA22 field. A total of ∼6000 candidate emission-line galaxies are found. We use deep ugrizJK data to obtain robust photometric redshifts. We combine our data with the High-redshift(Z) Emission Line Survey (HiZELS), explore spectroscopic surveys (VVDS, VIPERS) and obtain our own spectroscopic follow-up with KMOS, FMOS and MOSFIRE to derive large samples of high-redshift emission-line selected galaxies: 3471 Hα emitters at z = 0.8, 1343 [O iii] + Hβ emitters at z = 1.4 and 572 [O ii] emitters at z = 2.2. We probe comoving volumes of >106 Mpc3 and find significant overdensities, including an 8.5σ (spectroscopically confirmed) overdensity of Hα emitters at z = 0.81. We derive Hα, [O iii] + Hβ and [O ii] luminosity functions at z = 0.8, 1.4, 2.2, respectively, and present implications for future surveys such as Euclid. Our uniquely large volumes/areas allow us to subdivide the samples in thousands of randomized combinations of areas and provide a robust empirical measurement of sample/cosmic variance. We show that surveys for star-forming/emission-line galaxies at a depth similar to ours can only overcome cosmic-variance (errors <10 per cent) if they are based on volumes >5 × 105 Mpc3; errors on L* and ϕ* due to sample (cosmic) variance on surveys probing ∼104 and ∼105 Mpc3 are typically very high: ∼300 and ∼40–60 per cent, respectively.

Citation

Sobral, D., Matthee, J., Best, P., Smail, I., Khostovan, A., Milvang-Jensen, B., …Mobasher, B. (2015). CF-HiZELS, an ∼10 deg2 emission-line survey with spectroscopic follow-up: Hα, [O iii] + Hβ and [O ii] luminosity functions at z = 0.8, 1.4 and 2.2. Monthly Notices of the Royal Astronomical Society, 451(3), 2303-2323. https://doi.org/10.1093/mnras/stv1076

• Journal Article Type: Article
• Acceptance Date: May 11, 2015
• Publication Date: Aug 11, 2015
• Deposit Date: Feb 16, 2016
• Publicly Available Date: Feb 22, 2016
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 451
• Issue: 3
• Pages: 2303-2323
• DOI: https://doi.org/10.1093/mnras/stv1076
• Keywords: Galaxies: evolution, Galaxies: formation, Galaxies: luminosity function, mass function, Cosmology: observations, Early Universe, Large-scale structure of Universe.
• Public URL: https://durham-repository.worktribe.com/output/1411914
• Related Public URLs: http://adsabs.harvard.edu/abs/2015MNRAS.451.2303S