## Abstract

We present results of a survey for Lyα emitters at z ≈ 4.86 based on optical narrowband (λ_{c} = 7126 Å, Δλ = 73 Å) and broadband (B, V, r', i', and z') observations of the Cosmic Evolution Survey field using Suprime-Cam on the Subaru Telescope. We find 79 Lyα emitter (LAE) candidates at z ≈ 4.86 over a contiguous survey area of 1.83 deg^{2}, down to the Lyα line flux of 1.47 × 10 ^{-17}erg s^{-1} cm^{-2}. We obtain the Lyα luminosity function with a best-fit Schechter parameters of logL ^{*} = 42.9^{+0.5}_{-0.3} erg s^{-1} and φ^{*} = 1.2^{+8.0}_{-1.1} × 10 ^{-4} Mpc^{-3} for α = -1.5 (fixed). The two-point correlation function for our LAE sample is ξ (r) = (r/4.4^{+5.7} _{-2.9} Mpc)^{-1.90±0.22}. In order to investigate the field-to-field variations of the properties of Lyα emitters, we divide the survey area into nine tiles of 0°5 × 0°5 each. We find that the number density varies with a factor of ≃2 from field to field with high statistical significance. However, we find no significant field-to-field variance when we divide the field into four tiles with 0.7 × 0°7 each. We conclude that at least 0.5 deg^{2} survey area is required to derive averaged properties of LAEs at z ∼ 5, and our survey field is wide enough to overcome the cosmic variance.

Original language | English |
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Pages (from-to) | 546-561 |

Number of pages | 16 |

Journal | Astrophysical Journal |

Volume | 696 |

Issue number | 1 |

DOIs | |

Publication status | Published - 2009 May 1 |

## Keywords

- Galaxies: distances and redshifts
- Galaxies: evolution
- Galaxies: luminosity function
- Mass function