J/ApJ/902/137 Spectroscopic obs. of LAEs at z∼3.1 in SXDS field (Guo+, 2020)
A spectroscopic survey of Lyα emitters at z∼3.1 over ∼1.2deg2.
Guo Y., Jiang L., Egami E., Ning Y., Zheng Z.-Y., Ho L.C.
<Astrophys. J., 902, 137 (2020)>
=2020ApJ...902..137G 2020ApJ...902..137G
ADC_Keywords: Galaxies, spectra; Redshifts; Surveys; Ultraviolet;
Photometry, UBV
Keywords: High-redshift galaxies ; Lyman-alpha galaxies ; Galaxy properties
Abstract:
We present a spectroscopic survey of Lyα emitters (LAEs) at
z∼3.1 in the Subaru XMM-Newton Deep Survey Field. This field has deep
imaging data in a series of broad and narrow bands, including two
adjacent narrow bands NB497 and NB503 that have allowed us to
efficiently select LAE candidates at z∼3.1. Using spectroscopic
observations on MMT Hectospec and Magellan M2FS, we obtained a sample
of 166 LAEs at z∼3.1 over an effective area of ∼1.2deg2, including
16 previously known LAEs. This is so far the largest
(spectroscopically confirmed) sample of LAEs at this redshift. We make
use of the secure redshifts and multiband data to measure spectral
properties such as Lyα luminosity and rest-frame UV slope. We
derive a robust Lyα luminosity function (LF) that spans a
luminosity range from ∼1042.0 to >1043.5erg/s. Significant
overdense and underdense regions are detected in our sample, but the
area coverage is wide enough to largely suppress the effect from such
cosmic variance. Our Lyα LF is generally consistent with those
from previous studies at z∼3.1. At the brightest end of the LF, there
is a tentative detection of a density excess that is not well
described by the Schechter function. The comparison with the LFs at
other redshifts suggests that the Lyα LF does not show
significant evolution at 2<z<5. Finally, we build the composite
spectra of the LAEs and detect the NVλ1239 and
CIVλλ1548,1551 doublet emission lines at significance of
∼4σ, suggesting very hard radiation fields in (some of) these LAEs.
Description:
The Subaru XMM-Newton Deep Survey (SXDS) field
(RAJ2000=02:18:00.0,DEJ2000=-05:00:00.0) covers an area of ∼1.2deg2.
It has very deep imaging data in a series of broad and narrow bands
taken by the Subaru Suprime-Cam. We retrieved the raw data of
Suprime-Cam in the SXDS field from the archival server SMOKA.
The depths of the final combined images in five broad bands B, V, Rc,
i', z' are 27.9, 27.6, 27.4, 27.4, and 26.2mag, respectively. We used
two narrow bands NB497 and NB503 to select Lyα emitters (LAEs)
at z∼3.1. NB497 has a central wavelength of ∼4986Å with an FWHM of
78Å. NB503 has a central wavelength of ∼5030Å with an FWHM of 74Å.
After we obtained the sample of the LAE candidates, we carried out
spectroscopic observations using two multifiber spectrographs MMT
Hectospec on 2016 Oct 6, 9, 2017 Sep 28, Oct 1 and Magellan M2FS on
2016 Nov 28.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 81 166 The Lyα emitter (LAE) sample
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See also:
J/ApJ/671/1227 : Lyα galaxies at z∼4.5 (Dawson+, 2007)
J/ApJ/667/79 : Lyα emission-line galaxies at z=3.1 (Gronwall+, 2007)
J/ApJS/176/1 : Subaru/XMM-Newton deep survey (SXDS). II. (Furusawa+, 2008)
J/ApJS/176/301 : Subaru/XMM-Newton deep survey IV. (SXDS) (Ouchi+, 2008)
J/ApJ/736/31 : HETDEX pilot survey. II. 1.9<z<3.8 LAEs (Blanc+, 2011)
J/ApJ/744/110 : LAE galaxies between 2.1=<z≤3.1 (Ciardullo+, 2012)
J/ApJ/751/29 : Lyα profiles of LAEs at z=3.1 (Yamada+, 2012)
J/ApJ/783/119 : z∼1 Lyα emitters. I. Cand. from GALEX (Wold+, 2014)
J/MNRAS/471/267 : Lyα fluxes of HDFS 2.91<z<6.64 sources (Drake+, 2017)
J/MNRAS/466/1242 : CALYMHA survey. I. (Sobral+, 2017)
J/MNRAS/476/4725 : SC4K catalogue of candidate LAEs (Sobral+, 2018)
J/A+A/621/A107 : MUSE-Wide Ly alpha luminosity function 3<z<6 (Herenz+, 2019)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 -- Seq [1/166] Running sequence number
5- 12 F8.5 deg RAdeg [34.16/35.12] Right Ascension (J2000)
14- 21 F8.5 deg DEdeg [-5.6/-4.6] Declination (J2000)
23- 27 F5.3 -- z [3/3.161] Spectroscopic redshift (1)
29- 33 F5.2 10+35W L(Lya) [1/36.4]? Lya luminosity; 1042erg/s units
35- 39 F5.2 mag NB497 [22.73/25.84]? Subaru/Suprime-Cam apparent
NB497 AB magnitude (2)
41- 44 F4.2 mag e_NB497 [0.01/0.12]? Uncertainty in NB497
46- 50 F5.2 mag NB503 [22.4/25]? Subaru/Suprime-Cam apparent
NB503 AB magnitude (2)
52- 55 F4.2 mag e_NB503 [0.01/0.14]? Uncertainty in NB503
57 A1 --- l_Bmag [<] Upper limit flag on Bmag (3)
59- 63 F5.2 mag Bmag [24.2/29.02] Subaru/Suprime-Cam apparent
B band AB magnitude
65- 68 F4.2 mag e_Bmag [0.01/0.51]? Uncertainty in Bmag
70 A1 --- l_Vmag [<] Upper limit flag on Vmag (3)
72- 76 F5.2 mag Vmag [23.38/28.51] Subaru/Suprime-Cam apparent
V band AB magnitude
78- 81 F4.2 mag e_Vmag [0.01/0.21]? Uncertainty in Bmag
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Note (1): Redshift measured from the Lyα emission line. Its error
is typically less than 0.001.
Note (2): A blank value indicates the object is outside the covering sky region
of this filter.
Note (3): This is not a detection and the photometry is an upper limit.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 21-Apr-2022