J/MNRAS/416/2041 Hα emitters at z=2.23 (Matsuda+, 2011)
An Hα search for overdense regions at z = 2.23.
Matsuda Y., Smail I., Geach J.E., Best P.N., Sobral D., Tanaka I.,
Nakata F., Ohta K., Kurk J., Iwata I., Bielby R., Wardlow J.L., Bower R.G.,
Ivison R.J., Kodama T., Yamada T., Mawatari K., Casali M.
<Mon. Not. R. Astron. Soc., 416, 2041-2059 (2011)>
=2011MNRAS.416.2041M 2011MNRAS.416.2041M
ADC_Keywords: Surveys ; Photometry, H-alpha ; Equivalent widths
Keywords: galaxies: evolution - galaxies: formation - galaxies: high-redshift -
cosmology: observations - early Universe
Abstract:
We present the results of a narrow-band (H2S1, λc=2.121um,
δλ=0.021um) imaging search with Wide Field Camera/United
Kingdom Infrared Telescope for Hα emitters (HAEs) around several
potential signposts of rare (∼10-7-10-8 comoving Mpc-3)
overdense regions at z=2.23: an overdensity of quasi-stellar objects
[QSOs; 2dF QSO Redshift Survey (2QZ) cluster], a powerful,
high-redshift radio galaxy (HzRG) and a concentration of submillimetre
galaxies (SMGs) and optically faint radio galaxies (OFRGs). In total,
we detect 137 narrow-band emitter candidates down to emission-line
fluxes of 0.5-1x10-16erg/s/cm2, across a total area of 0.56deg2
(2.1x105 comoving Mpc3 at z=2.23) in these fields.
Description:
The three target fields (2QZ cluster, 0200+015 and SSA 13) were
observed between 2006 May and 2010 April with WFCAM on UKIRT, using
the K band and H2S1 filters.
To check contamination in our emitter sample from foreground and
background line emitters, we obtained B- and z -band images of the
target fields with Subaru/Subaru Prime Focus Camera (Suprime-Cam).
We observed the 2QZ cluster field in 2009 November and the 0200+015
field in 2010 November. For the SSA 13 field, we used archival data.
The 0200+015 field was also observed with the Ks band and H2S1 filters
using Subaru/Multi-Object Infrared Camera and Spectrograph (MOIRCS)
in 2007 August as part of engineering tests (performed by IT).
In addition, we carried out a long-slit spectroscopic observation of a
bright emitter candidate in the 0200+015 field with Keck/Low
Resolution Imaging Spectrometer (LRIS) in 2010 September.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 92 66 Properties of the emitter candidates in the
2QZ cluster (C1) and control fields (C2, C3, C4)
tablea2.dat 94 51 Properties of the emitter candidates in the
0200+015 field (C3) and control fields (C1, C2, C4)
tablea3.dat 92 20 Properties of the emitter candidates in the
SSA 13 field (C1) and control fields (C2, C3, C4)
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Byte-by-byte Description of file: tablea?.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- ID Source name (1)
16- 17 I2 h RAh Right ascension (J2000)
19- 20 I2 min RAm Right ascension (J2000)
22- 26 F5.2 s RAs Right ascension (J2000)
28 A1 --- DE- Declination sign (J2000)
29- 30 I2 deg DEd Declination (J2000)
32- 33 I2 arcmin DEm Declination (J2000)
35- 38 F4.1 arcsec DEs Declination (J2000)
40- 44 F5.2 mag H2S1 Magnitude in H2S1 filter (2.121±0.021um)
46 A1 --- l_Kmag Limit flag on Kmag
47- 51 F5.2 mag Kmag K magnitude
53 A1 --- l_sigma Limit flag on sigma
54- 58 F5.1 --- sigma Ratio between the H2S1 excess and the
uncertainty in the K-H2S1 colour
60 A1 --- l_EWobs Limit flag on EWobs
61- 65 I5 0.1nm EWobs Observed Hα equivalent width
67- 72 F6.2 [mW/cm2] logFHa Hα flux corrected for 33% [NII]
contribution to the measured flux
74- 78 F5.2 [10-7W] logLHa Hα luminosity
80- 82 I3 Msun/yr SFRHa The attenuation-uncorrected SFR derived from
the Hα luminosity
84 A1 --- l_M Limit flag on M
85- 88 F4.1 Msun M The stellar mass estimated from the K-band
magnitude by assuming a constant mass-to-light
ratio from Geach at al. 2008MNRAS.388.1473G 2008MNRAS.388.1473G
90- 94 A5 --- Class Class of object as BzK, QSO, HzRG, NLAGN (2)
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Note (1): Designations as <2QZC-CN-HAENN> for tablea1,
<0200-CN-HAENN> for tablea2, and <SSA13-CN-HAENN> for tablea3.
Note (2): Note as follows:
BzK = star-forming galaxy according to the BzK criteria:
(z-K)AB-(B-z)AB≥-0.2 or (z-K)AB>2.5
QSO = quasi-stellar objects
HzRG = high-redshift radio galaxies
NLAGN = narrow-line AGN
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 09-Apr-2012