A large, deep 3 deg2 survey of H α, [O  iii ], and [O  ii ] emitters from LAGER: constraining luminosity functions

Journal Article · Mon Jan 20 00:00:00 EST 2020 · Monthly Notices of the Royal Astronomical Society

DOI:https://doi.org/10.1093/mnras/staa175· OSTI ID:1604810

Khostovan, A. A.  ^[1]; Malhotra, S. ^[2]; Rhoads, J. E. ^[2]; Jiang, C. ^[3]; Wang, J. ^[4]; Wold, I. ^[1]; Zheng, Z-Y ^[3]; Barrientos, L. F. ^[5]; Coughlin, A. ^[6]; Harish, S. ^[7]; Hu, W. ^[4]; Infante, L. ^[8]; Perez, L. A. ^[7]; Pharo, J. ^[7]; Valdes, F. ^[9]; Walker, A. R. ^[10]; Yang, H. ^[11]

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1. Astrophysics Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
2. Astrophysics Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA, School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287, USA
3. CAS Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Shanghai 200030, China
4. CAS Key Laboratory for Research in Galaxies and Cosmology, University of Science and Technology of China, Hefei, Anhui 230026, China
5. Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Santiago 8970117, Chile
6. School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287, USA, Chandler-Gilbert Community College, 2626 East Pecos Road, Chandler, AZ 85225-2499, USA
7. School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287, USA
8. Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Santiago 8970117, Chile, Las Campanas Observatory, Observatories of the Carnegie Institution of Washington, La Serena, Chile, Núcleo de Astronomía, Universidad Diego Portales, Santiago, Chile
9. National Optical Astronomy Observatory, 950 N. Cherry Avenue, Tucson, AZ 85719, USA
10. Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, Casilla 603, La Serena, Chile
11. Las Campanas Observatory, Observatories of the Carnegie Institution of Washington, La Serena, Chile

ABSTRACT We present our measurements of the H α, [O iii], and [O ii] luminosity functions as part of the Lyman Alpha Galaxies at Epoch of Reionization (LAGER) survey using our samples of 1577 z = 0.47 H α-, 3933 z = 0.93 [O iii]-, and 5367 z = 1.59 [O ii]-selected emission line galaxies in a 3 deg2 single, CTIO/Blanco DECam pointing of the COSMOS field. Our observations reach 5σ depths of 8.2 × 10−18 erg s−1 cm−2 and comoving volumes of (1−7) × 105 Mpc3 making our survey one of the deepest narrow-band surveys. We select our emission line galaxies via spectroscopic confirmation, photometric redshifts, and colour–colour selections. We measure the observed luminosity functions for each sample and find best fits of $$\phi ^\star = 10^{-3.16^{+0.09}_{-0.09}}$$ Mpc−3 and $$L^\star = 10^{41.72^{+0.09}_{-0.09}}$$ erg s−1 for H α, $$\phi ^\star = 10^{-2.16^{+0.10}_{-0.12}}$$ Mpc−3 and $$L^\star = 10^{41.38^{+0.07}_{-0.06}}$$ erg s−1 for [O iii], and $$\phi ^\star = 10^{-1.97^{+0.07}_{-0.07}}$$ Mpc−3 and $$L^\star = 10^{41.66^{+0.03}_{-0.03}}$$ erg s−1 for [O ii], with α fixed to −1.75, −1.6, and −1.3, respectively. An excess of bright >1042 erg s−1 [O iii] emitters is observed and may be due to active galactic nucleus (AGN) contamination. Corrections for dust attenuation are applied assuming AHα = 1 mag. We also design our own empirical rest-frame g − r calibration using SDSS DR12 data, test it against our z = 0.47 H α emitters with zCOSMOS 1D spectra, and calibrate it for (g − r) between −0.8 and 1.3 mag. Dust and AGN-corrected star formation rate densities (SFRDs) are measured as log10ρSFR/(M⊙ yr−1 Mpc−3) = −1.63 ± 0.04, −1.07 ± 0.06, and −0.90 ± 0.10 for H α, [O iii], and [O ii], respectively. We find our [O iii] and [O ii] samples fully trace cosmic star formation activity at their respective redshifts in comparison to multiwavelength SFRDs, while the H α sample traces ∼70 per cent of the total z = 0.47 SFRD.

• Sponsoring Organization: USDOE
• OSTI ID: 1604810
• Journal Information: Monthly Notices of the Royal Astronomical Society, Journal Name: Monthly Notices of the Royal Astronomical Society Vol. 493 Journal Issue: 3; ISSN 0035-8711
• Publisher: Oxford University Press
• Country of Publication: United Kingdom
• Language: English