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Photometric properties of Ly alpha emitters at z=4.86 in the COSMOS 2 square degree field
Astrophysical Journal (2009)
  • Y. Shioya
  • Y. Taniguchi
  • S. S. Sasaki
  • T. Nagao
  • T. Murayama
  • T. Saito
  • Y. Ideue
  • A. Nakajima
  • K. L. Matsuoka
  • J. Trump
  • N. Z. Scoville
  • D. B. Sanders
  • B. Mobasher
  • H. Aussel
  • P. Capak
  • J. Kartaltepe
  • A. Koekemoer
  • C. Carilli
  • R. S. Ellis
  • B. Garilli
  • Mauro Giavalisco, University of Massachusetts - Amherst
  • M. G. Kitzbichler
  • C. Impey
  • O. LeFevre
  • E. Schinnerer
  • V. Smolcic
We present results of a survey for Ly alpha emitters at z=4.86 based on optical narrowband (lambda_c=7126 angstrom, Delta lambda=73 angstrom) and broadband (B, V, r', i', and z') observations of the Cosmic Evolution Survey (COSMOS) field using Suprime-Cam on the Subaru Telescope. We find 79 LAE candidates at z=4.86 over a contiguous survey area of 1.83 deg^2, down to the Ly alpha line flux of 1.47 x 10^-17 ergs s^-1 cm^-2. We obtain the Ly alpha luminosity function with a best-fit Schechter parameters of log L^*=42.9^+0.5_-0.3 ergs s^-1 and phi^* = 1.2^+8.0_-1.1 x 10^-4 Mpc^-3 for alpha=-1.5 (fixed). The two-point correlation function for our LAE sample is xi(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 Ly alpha emitters, we divide the survey area into nine tiles of 0.5^circ x 0.5^circ 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^circ x 0.7^circ 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.
  • galaxies: distances and redshifts,
  • galaxies: evolution,
  • galaxies: luminosity function,
  • mass function
Publication Date
Publisher Statement
This paper was harvested from and ArXiv identifier is arXiv:0901.4627
Citation Information
Y. Shioya, Y. Taniguchi, S. S. Sasaki, T. Nagao, et al.. "Photometric properties of Ly alpha emitters at z=4.86 in the COSMOS 2 square degree field" Astrophysical Journal (2009)
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