TY - JOUR
T1 - Boötes-HiZELS
T2 - An optical to near-infrared survey of emission-line galaxies at z = 0.4-4.7
AU - Matthee, Jorryt
AU - Sobral, David
AU - Best, Philip
AU - Smail, Ian
AU - Bian, Fuyan
AU - Darvish, Behnam
AU - Röttgering, Huub
AU - Fan, Xiaohui
N1 - Funding Information:
We thank the referee for their constructive comments which helped improve the quality of this work. JM acknowledges the support of a Huygens PhD fellowship from Leiden University and JM and DS acknowledge financial support from a NWO/VENI grant awarded to David Sobral. IRS acknowledges support from STFC (ST/L00075X/1), the ERC Advanced Grant DUSTYGAL (321334) and a Royal Society/Wolfson Merit Award. HR acknowledges support from the ERC Advanced Investigator programme New-Clusters 321271. PNB is grateful to STFC for support via grant ST/M001229/1. BD acknowledges financial support from NASA through the Astrophysics Data Analysis Program (ADAP), grant number NNX12AE20G. We thank Ana Afonso, João Calhau, Leah Morabito, Iván Oteo, Sérgio Santos and Aayush Saxena for their assistance with observations. This work is based on observations obtained using the Wide Field Camera (WFCAM) on the 3.8-m United Kingdom Infrared Telescope (UKIRT), as part of the High-redshift(Z) Emission-Line Survey (HiZELS; U/CMP/3 and U/10B/07), using Suprime-Cam on the 8.2-m Subaru Telescope as part of programme S14A-086 and using the WFC on the 2.5-m Isaac Newton Telescope, as part of programmes 2013AN002, 2013BN008, 2014AC88, 2014AN002, 2014BN006, 2014BC118 and 2016AN001, using ISIS and AF2+WYFFOS on the 4.2-m William Herschel Telescope, as part of programmes 2016AN004 and 2016BN011 and using DEIMOS on the 10-m Keck II Telescope as part of programme C267D and on observations made with ESO Telescopes at the La Silla Paranal Observatory under ESO programme IDs 098.A-0819 and 179.A-2005. This work made use of images and/or data products provided by the NOAO Deep Wide-Field Survey (Jannuzi & Dey 1999) which is supported by the National Optical Astronomy Observatory (NOAO). NOAO is operated by AURA, Inc., under a cooperative agreement with the National Science Foundation. We have benefited greatly from the public available programming language PYTHON, including the NUMPY, MATPLOTLIB, PYFITS, SCIPY and ASTROPY packages (Astropy Collaboration et al. 2013), the astronomical imaging tools SEXTRACTOR, SWARP and SCAMP and the TOPCAT analysis program (Taylor 2013).
Publisher Copyright:
© 2017 The Authors.
PY - 2017/10/11
Y1 - 2017/10/11
N2 - We present a sample of~1000 emission-line galaxies at z=0.4-4.7 from the~0.7deg2 High-z Emission-Line Survey in the Boötes field identified with a suite of six narrow-band filters at ≈0.4-2.1 μm. These galaxies have been selected on their Lyα (73), [OII] (285), Hβ/[OIII] (387) or Hα (362) emission line, and have been classified with optical to near-infrared colours. A subsample of 98 sources have reliable redshifts from multiple narrow-band (e.g. [OII]-Hα) detections and/or spectroscopy. In this survey paper, we present the observations, selection and catalogues of emitters. We measure number densities of Lyα, [OII], Hβ/[OIII] and Hα and confirm strong luminosity evolution in star-forming galaxies from z ~ 0.4 to ~5, in agreement with previous results. To demonstrate the usefulness of dual-line emitters, we use the sample of dual [OII]-Hα emitters to measure the observed [OII]/Hα ratio at z = 1.47. The observed [OII]/Hα ratio increases significantly from 0.40±0.01 at z = 0.1 to 0.52±0.05 at z = 1.47, which we attribute to either decreasing dust attenuation with redshift, or due to a bias in the (typically) fibre measurements in the local Universe that only measure the central kpc regions. At the bright end, we find that both the Hα and Lyα number densities at z ≈ 2.2 deviate significantly from a Schechter form, following a power law. We show that this is driven entirely by an increasing X-ray/active galactic nucleus fraction with line luminosity, which reaches ≈100 per cent at line luminosities L ≳ 3 × 1044 erg s-1.
AB - We present a sample of~1000 emission-line galaxies at z=0.4-4.7 from the~0.7deg2 High-z Emission-Line Survey in the Boötes field identified with a suite of six narrow-band filters at ≈0.4-2.1 μm. These galaxies have been selected on their Lyα (73), [OII] (285), Hβ/[OIII] (387) or Hα (362) emission line, and have been classified with optical to near-infrared colours. A subsample of 98 sources have reliable redshifts from multiple narrow-band (e.g. [OII]-Hα) detections and/or spectroscopy. In this survey paper, we present the observations, selection and catalogues of emitters. We measure number densities of Lyα, [OII], Hβ/[OIII] and Hα and confirm strong luminosity evolution in star-forming galaxies from z ~ 0.4 to ~5, in agreement with previous results. To demonstrate the usefulness of dual-line emitters, we use the sample of dual [OII]-Hα emitters to measure the observed [OII]/Hα ratio at z = 1.47. The observed [OII]/Hα ratio increases significantly from 0.40±0.01 at z = 0.1 to 0.52±0.05 at z = 1.47, which we attribute to either decreasing dust attenuation with redshift, or due to a bias in the (typically) fibre measurements in the local Universe that only measure the central kpc regions. At the bright end, we find that both the Hα and Lyα number densities at z ≈ 2.2 deviate significantly from a Schechter form, following a power law. We show that this is driven entirely by an increasing X-ray/active galactic nucleus fraction with line luminosity, which reaches ≈100 per cent at line luminosities L ≳ 3 × 1044 erg s-1.
KW - Galaxies: active
KW - Galaxies: evolution
KW - Galaxies: high-redshift
KW - Galaxies: luminosity function
KW - Galaxies: star formation
KW - Mass function
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U2 - 10.1093/mnras/stx1569
DO - 10.1093/mnras/stx1569
M3 - Article
AN - SCOPUS:85032826184
SN - 0035-8711
VL - 471
SP - 629
EP - 649
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 1
ER -