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Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - CF-HiZELS, an ∼10 deg2 emission-line survey with spectroscopic follow-up
T2 - Hα, [O III] + Hβ and [O II] luminosity functions at z = 0.8, 1.4 and 2.2
AU - Sobral, David
AU - Matthee, Jorryt
AU - N. Best, Philip
AU - Smail, Ian
AU - A. Khostovan, Ali
AU - Milvang-Jensen, Bo
AU - Kim, Jae-Woo
AU - Stott, John
AU - Calhau, Joao
AU - Nayyeri, Hooshang
AU - Mobasher, Bahram
PY - 2015/8/11
Y1 - 2015/8/11
N2 - We present results from the largest contiguous narrow-band survey in the near-infrared. We have used WIRCam/CFHT and the lowOH2 filter (1.187$\pm$0.005 \mu m) to survey ~10 deg$^2$ of contiguous extragalactic sky in the SA22 field. A total of ~6000 candidate emission-line galaxies are found. We use deep CFHTLS $ugriz$ and UKIDSS DXS $J$ and $K$ data to obtain robust photometric redshifts. We combine our data with HiZELS (COSMOS+UDS) and explore VVDS, VIPERS, KMOS and obtain our own spectroscopic follow-up with FMOS and MOSFIRE to derive large samples of high-redshift emission-line selected galaxies: 3471 H\alpha\ emitters at z=0.8, 1343 [OIII]+H\beta\ emitters at z=1.4 and 572 [OII] emitters at z=2.2. We probe co-moving volumes of >10$^6$ Mpc$^3$ and find significant over-densities, including an 8.5\sigma\ (spectroscopically confirmed) over-density of H\alpha\ emitters at z=0.81. We derive H\alpha, [OIII]+H\beta\ and [OII] luminosity functions at z=0.8, 1.4 and 2.2, respectively, and present implications for future surveys such as EUCLID. Our uniquely large volumes/areas allow us to sub-divide the samples in thousands of randomised 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 5x10$^5$ Mpc$^3$; errors on L$^*$ and \Phi$^*$ due to sample (cosmic) variance on surveys probing ~10${^4}$ Mpc$^3$ and ~10$^5$ Mpc$^3$ are typically very high: ~300% and ~40-60%, respectively.
AB - We present results from the largest contiguous narrow-band survey in the near-infrared. We have used WIRCam/CFHT and the lowOH2 filter (1.187$\pm$0.005 \mu m) to survey ~10 deg$^2$ of contiguous extragalactic sky in the SA22 field. A total of ~6000 candidate emission-line galaxies are found. We use deep CFHTLS $ugriz$ and UKIDSS DXS $J$ and $K$ data to obtain robust photometric redshifts. We combine our data with HiZELS (COSMOS+UDS) and explore VVDS, VIPERS, KMOS and obtain our own spectroscopic follow-up with FMOS and MOSFIRE to derive large samples of high-redshift emission-line selected galaxies: 3471 H\alpha\ emitters at z=0.8, 1343 [OIII]+H\beta\ emitters at z=1.4 and 572 [OII] emitters at z=2.2. We probe co-moving volumes of >10$^6$ Mpc$^3$ and find significant over-densities, including an 8.5\sigma\ (spectroscopically confirmed) over-density of H\alpha\ emitters at z=0.81. We derive H\alpha, [OIII]+H\beta\ and [OII] luminosity functions at z=0.8, 1.4 and 2.2, respectively, and present implications for future surveys such as EUCLID. Our uniquely large volumes/areas allow us to sub-divide the samples in thousands of randomised 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 5x10$^5$ Mpc$^3$; errors on L$^*$ and \Phi$^*$ due to sample (cosmic) variance on surveys probing ~10${^4}$ Mpc$^3$ and ~10$^5$ Mpc$^3$ are typically very high: ~300% and ~40-60%, respectively.
KW - galaxies: evolution
KW - galaxies: formation
KW - galaxies: luminosity function, mass function
KW - cosmology: observations
KW - early Universe
KW - large-scale structure of Universe
U2 - 10.1093/mnras/stv1076
DO - 10.1093/mnras/stv1076
M3 - Journal article
VL - 451
SP - 2303
EP - 2323
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 3
ER -