Photometric properties of Ly alpha emitters at z=4.86 in the COSMOS 2 square degree field

Autor: Shioya, Y., Taniguchi, Y., Sasaki, S. S., Nagao, T., Murayama, T., Saito, T., Ideue, Y., Nakajima, A., Matsuoka, K. L., Trump, J., Scoville, N. Z., Sanders, D. B., Mobasher, B., Aussel, H., Capak, P., Kartaltepe, J., Koekemoer, A., Carilli, C., Ellis, R. S., Garilli, B., Giavalisco, M., Kitzbichler, M. G., Impey, C., LeFevre, O., Schinnerer, E., Smolcic, V.
Rok vydání: 2009
Předmět:
Zdroj: Astrophys.J.696:546-561,2009
Druh dokumentu: Working Paper
DOI: 10.1088/0004-637X/696/1/546
Popis: 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.
Comment: 24 pages, 13 figures, 4 tables, uses emulateapj sty, accepted for publication in ApJ
Databáze: arXiv
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