J/ApJ/696/546 Lyα emitters at z∼4.86 (Shioya+, 2009)
Photometric properties of Lyα emitters at z∼4.86 in the COSMOS 2 square
degree field.
Shioya Y., Taniguchi Y., Sasaki S.S., Nagao T., Murayama T., Saito T.,
Ideue Y., Nakajima A., Matsuoka K., 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.
<Astrophys. J., 696, 546-561 (2009)>
=2009ApJ...696..546S 2009ApJ...696..546S
ADC_Keywords: Galaxies, optical ; Ultraviolet ; Photometry, ugriz
Keywords: galaxies: distances and redshifts - galaxies: evolution -
galaxies: luminosity function, mass function
Abstract:
We present results of a survey for Lyα emitters at z∼4.86 based
on optical narrowband (λc=7126Å, Δλ=73Å) 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 1.83deg2, down to the Lyα line flux of
1.47x10-17erg/s/cm2. We obtain the Lyα luminosity function
with a best-fit Schechter parameters of log L*=42.9+0.5-0.3erg/s
and Φ*=1.2+8.0-1.1x10-4Mpc-3 for α=-1.5 (fixed). The
two-point correlation function for our LAE sample is
ξ(r)=(r/4.4+5.7-2.9Mpc)-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 0.5x0.5° 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 0.7x0.7° each. We conclude that at least 0.5deg2
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.
Description:
We carried out an optical narrowband (NB711; λc=7126±73Å)
imaging survey of the entire 2deg2 area of the COSMOS field, using
the Suprime-Cam on the Subaru Telescope in 2006 February.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 77 79 Photometric properties of Lyα emitter
(LAE) candidates
--------------------------------------------------------------------------------
See also:
J/A+A/498/13 : Lyman-α emitters from redshifts z∼2-3 (Nilsson+, 2009)
J/ApJS/175/128 : Hα emitting galaxies in COSMOS-2 field (Shioya+, 2008)
J/ApJS/172/456 : [OII] emitting galaxies in COSMOS + SDF fields (Takahashi+,
2007)
J/ApJS/172/523 : COSMOS field Lyα emitters at z∼5.7 (Murayama+, 2007)
J/PASJ/58/313 : Lyα emitters in the SUBARU Deep Field (Shimasaku+, 2006)
J/ApJ/648/7 : Lyα emitters at z=6.5 in Subaru Deep Field (Kashikawa+,
2006)
J/PASJ/57/165 : Lyα emitters in the SUBARU Deep Field (Taniguchi+, 2005)
J/PASJ/57/881 : Imaging of high-redshift Lyman alpha emitters (Yamada+, 2005)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Seq Object number (<[STS2009] NN> in Simbad)
4- 12 F9.5 deg RAdeg Right ascension in decimal degrees (J2000)
14- 21 F8.6 deg DEdeg Declination in decimal degrees (J2000)
23- 27 F5.2 mag r'mag ?=99 Subaru r'-band AB magnitude
29- 33 F5.2 mag i'mag Subaru i'-band AB magnitude
35- 39 F5.2 mag rimag Subaru ri-band AB magnitude (1)
41- 45 F5.2 mag NB711 Subaru NB711-band AB magnitude (1)
47 A1 --- l_z'mag Limit flag on z'mag
48- 52 F5.2 mag z'mag Subaru z'-band AB magnitude
54- 58 F5.2 [10-7W] logL(Lya) Log of Lyα luminosity
60 A1 --- l_logLnu Limit flag on logLnu
61- 65 F5.2 [10-7W/Hz] logLnu Log of luminosity at 1540Å in erg/s/Hz
67 A1 --- l_UVMag Limit flag on UVMag
68- 72 F5.1 mag UVMag Absolute UV-band AB magnitude at
rest-frame 1540Å
74 A1 --- l_EW0 Limit flag on EW0
75- 77 I3 0.1nm EW0 Equivalent width (EW0) (2)
-------------------------------------------------------------------------------
Note (1): NB711 is the optical narrowband defined as λc=7126±73Å.
Since the effective frequency of the NB711 filter (421.1THz) lies
between r' (482.8THz) and i' (394.0THz) bands, we estimate the
frequency-matched continuum, "ri continuum," using the linear
combination: fri=0.3fr'+0.7fi', where fr' and fi' are the
flux densities in r' and i' bands, respectively.
See section 2.2 for further details.
Note (2): As indicated in the erratum (2009, ApJ, 700, 899), EW0 values
of table 1 in the original paper have been multiplied by 0.83 at CDS.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 06-May-2011