J/ApJ/706/762 LAEs at z∼4.5 in the LALA Cetus field (Wang+, 2009)
Lyα-emitting galaxies at redshift z∼ 4.5 in the LALA Cetus field.
Wang J.-X., Malhotra S., Rhoads J.E., Zhang H.-T., Finkelstein S.L.
<Astrophys. J., 706, 762-771 (2009)>
=2009ApJ...706..762W 2009ApJ...706..762W
ADC_Keywords: Galaxies, spectra ; Redshifts ; Equivalent widths ; Surveys
Keywords: cosmology: observations - early universe - galaxies: evolution -
galaxies: formation - galaxies: high-redshift
Abstract:
We present a large sample of Lyα-emitting galaxies (LAEs)
spectroscopically confirmed at redshift z∼4.5, based on
Inamori-Magellan Areal Camera and Spectrograph spectroscopic
observations of candidate z∼4.5 Lyα-emitting galaxies in the
large area Lyman alpha (LALA) narrowband imaging survey Cetus field.
We identify 110 of them as z∼4.5 Lyα emitters based on
single-line detections with no continuum emission blueward of the
line. Six foreground galaxies are identified, either based on multiple
lines or blueward continuum emission. The Lyα confirmation rate
varies from <50% to 76% for candidates selected in different
narrowband filters at slightly different redshifts. The sample
includes many objects with equivalent widths (EWs)≳200Å. These
large EW candidates are spectroscopically confirmed at the same rate
as candidates with more modest EWs.
Description:
We obtained the narrowband images used to select z∼4.5 Lyα
galaxy candidates for this work using CCD cameras at the National
Optical Astronomy Observatory's 4m telescopes (the Mayall Telescope at
Kitt Peak National Observatory, and the Blanco Telescope at Cerro
Tololo Inter-American Observatory). We observed the LALA Cetus field
(02:05:20-04:55; J2000.0). In total, we obtained deep narrowband
stacks over a 36'x36' field in five distinct but overlapping filters,
each with full width at half-maximum (FWHM)∼80Å. The central
wavelengths are 6559, 6611, 6650, 6692, and 6730Å for narrowband
filters Ha0, Ha4, Ha8, Ha12, and Ha16, respectively.
To study the continuum emission properties of our candidates, we used
deep broadband images in BW, R, I band from the NOAO Deep Wide Field
Survey (NDWFS; Jannuzi & Dey 1999ASPC..193..258J 1999ASPC..193..258J).
In 2005 September 3-5, we obtained spectroscopy of 194 candidates
z∼4.5 Lyα emitters in the LALA Cetus field using the
Inamori-Magellan Areal Camera and Spectrograph (IMACS) on the 6.5m
Magellan I Baade Telescope. The spectral resolution is ∼7Å.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 48 110 IMACS spectroscopically confirmed Lyα
emitters at z∼4.5 in the LALA Cetus field
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See also:
J/ApJ/704/548 : Photometric properties of galaxies at z=4-6 (Overzier+, 2009)
J/ApJ/696/546 : Lyα emitters at z∼4.86 (Shioya+, 2009)
J/ApJ/671/1227 : Lyα galaxies at z∼4.5 (Dawson+, 2007)
J/A+A/461/823 : Candidate Lyα emitting galaxies (Venemans+, 2007)
J/ApJ/669/765 : Chandra X-ray sources in LALA Cetus field (Wang+, 2007)
J/PASJ/57/881 : Imaging of high-redshift Lyman alpha emitters (Yamada+, 2005)
J/AJ/127/213 : LALA Bootes field X-ray source catalog (Wang+, 2004)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- [WMR2009] Target designation (JHHMMSS.s+DDMMSS)
18- 22 F5.3 --- z Spectroscopic redshift (1)
24- 28 F5.3 10-20W/m2 FLya Lyα line flux (2)
30- 34 F5.3 10-20W/m2 e_FLya FLya uncertainty
36 A1 --- l_EW Limit flag on EW
37- 39 I3 0.1nm EW Rest-frame equivalent width in Angstroms (3)
41- 44 I4 0.1nm E_EW ? Positive error in EW
46- 48 I3 0.1nm e_EW ? Negative error in EW
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Note (1): The redshift was measured from the wavelength of the peak pixel
in the line profile from one-dimensional spectra. Due to the
uncertainties in the wavelength calibration (see the text for
details), we expect the error in the measurement to be δz∼0.005.
Note (2): The line flux was measured based on narrowband and broadband
photometry, in units of 10-17erg/cm2/s.
Note (3): The EW were obtained based on broadband and narrowband
photometry. See Section 3.3 for details.
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 14-Dec-2011