J/ApJS/192/5 Emission-line galaxies from HETDEX pilot survey (Adams+, 2011)
The HETDEX pilot survey. I. Survey design, performance, and catalog of
emission-line galaxies.
Adams J.J., Blanc G.A., Hill G.J., Gebhardt K., Drory N., Hao L.,
Bender R., Byun J., Ciardullo R., Cornell M.E., Finkelstein S.L., Fry A.,
Gawiser E., Gronwall C., Hopp U., Jeong D., Kelz A., Kelzenberg R.,
Komatsu E., MacQueen P.J., Murphy J., Odoms P.S., Roth M., Schneider D.P.,
Tufts J.R., Wilkinson C.P.
<Astrophys. J. Suppl. Ser., 192, 5 (2011)>
=2011ApJS..192....5A 2011ApJS..192....5A
ADC_Keywords: Galaxies, optical ; Equivalent widths ; Redshifts ; Surveys
Keywords: cosmology: observations - galaxies: evolution - galaxies: formation -
galaxies: high-redshift
Abstract:
We present a catalog of emission-line galaxies selected solely
by their emission-line fluxes using a wide-field integral field
spectrograph. This work is partially motivated as a pilot survey
for the upcoming Hobby-Eberly Telescope Dark Energy Experiment.
We describe the observations, reductions, detections, redshift
classifications, line fluxes, and counterpart information for 397
emission-line galaxies detected over 169arcmin2 with a 3500-5800Å
bandpass under 5Å full-width-half-maximum (FWHM) spectral resolution.
The survey's best sensitivity for unresolved objects under photometric
conditions is between 4 and 20x10-17erg/s/cm2 depending on the
wavelength, and Lyα luminosities between 3x1042 and
6x1042erg/s are detectable. This survey method complements
narrowband and color-selection techniques in the search of
high-redshift galaxies with its different selection properties and
large volume probed. The four survey fields within the COSMOS,
GOODS-N, MUNICS, and XMM-LSS areas are rich with existing,
complementary data. We find 105 galaxies via their high-redshift
Lyα emission at 1.9<z<3.8, and the majority of the remainder
objects are low-redshift [OII]3727 emitters at z<0.56. The
classification between low- and high-redshift objects depends on
rest-frame equivalent width (EW), as well as other indicators, where
available. Based on matches to X-ray catalogs, the active galactic
nuclei fraction among the Lyα emitters is 6%. We also analyze
the survey's completeness and contamination properties through
simulations. We find five high-z, highly significant, resolved objects
with FWHM sizes >44arcmin2 which appear to be extended Lyα
nebulae. We also find three high-z objects with rest-frame Lyα
EW above the level believed to be achievable with normal star
formation, EW0>240Å.
Description:
We obtained regular fall/winter/spring dark time observations from
2007 September to 2010 February on the McDonald 2.7m Harlan J. Smith
telescope with the Visible Integral-field Replicable Unit Spectrograph
Prototype (VIRUS-P).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 94 4 Ancillary broadband imaging properties
table3.dat 98 479 HETDEX pilot survey emission line catalog
table4.dat 112 479 HETDEX pilot survey emission line classifications
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See also:
J/MNRAS/401/294 : Optical identification of XMM-LSS sources (Stalin+, 2010)
J/A+A/490/879 : XMM-LSS field optical identifications (Tasse+, 2008)
J/ApJ/667/79 : Lyα emission-line galaxies at z=3.1 (Gronwall+, 2007)
J/ApJ/653/1004 : Galaxies at 1.4≲z≲3.0 in GOODS-North Field (Reddy+, 2006)
J/AJ/130/2584 : KISS emission-line galaxy candidates. IV (Salzer+, 2005)
J/AJ/112/1335 : Hubble Deep Field observations (Williams+ 1996)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Field Field name (1)
11- 12 I2 h RAh Central hour of right ascension (J2000)
14- 15 I2 min RAm Central minute of right ascension (J2000)
17- 18 I2 s RAs Central second of right ascension (J2000)
20 A1 --- DE- Declination sign (J2000)
21- 22 I2 deg DEd Central degree of declination (J2000)
24- 25 I2 arcmin DEm Central arcminute of declination (J2000)
27- 28 I2 arcsec DEs Central arcsecond of declination (J2000)
30- 34 F5.3 mag E(B-V) Galactic extinction value
36- 62 A27 --- Filt Filters
64 A1 --- f_Filt [a] Flag for u filter
66- 69 F4.2 arcsec Seeing The worst seeing FWHM to which all bands are
matched
71- 79 A9 --- Stack Filters combined to form the detection image
81- 84 A4 --- BandK The band chosen for Kron aperture measurement
86- 89 F4.1 --- Depth The 5σ limit in AB magnitudes for a
point source in a 2" aperture for the band
with the Kron aperture measurement
91- 94 F4.1 arcmin2 Area Visible Integral-field Replicable Unit
Spectrograph Prototype (VIRUS-P) area
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Note (1): Fields as follows:
COSMOS = from the Cosmological Evolution Survey (Scoville et al.
2007ApJS..172....1S 2007ApJS..172....1S),
GOODS-N = from the surrounding Great Observatories Origins Deep Survey North
(Dickinson et al. 2003mglh.conf..324D),
XMM-LSS = from the XMM Large-Scale Structure field (Pierre et al.
2004JCAP...09..011P 2004JCAP...09..011P)
MUNICS = from the Munich Near-IR Cluster Survey (Drory et al.
2001MNRAS.325..550D 2001MNRAS.325..550D).
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- HPS [1/479] HETDEX Pilot Survey index number
5- 6 I2 h RAh Hour of Right Ascension (J2000)
8- 9 I2 min RAm Minute of Right Ascension (J2000)
11- 15 F5.2 s RAs Second of Right Ascension (J2000)
17 A1 --- DE- Sign of the Declination (J2000)
18- 19 I2 deg DEd Degree of Declination (J2000)
21- 22 I2 arcmin DEm Arcminute of Declination (J2000)
24- 28 F5.2 arcsec DEs Arcsecond of Declination (J2000)
30- 36 F7.2 0.1nm lambda Observed emission wavelength (1)
38- 41 I4 km/s FWHM Emission line intrinsic FWHM (2)
43- 47 F5.1 --- S/N Emission line Signal-to-Noise
49- 54 F6.1 10-20W/m2 Flux Emission line flux (in 10-17erg/cm2/s) (3)
56- 59 F4.1 10-20W/m2 e_Flux Lower limit uncertainty in Flux
61- 64 F4.1 10-20W/m2 E_Flux Upper limit uncertainty in Flux
66- 69 F4.1 arcsec Spat Emission line spatial FWHM (3)
71- 73 F3.1 arcsec e_Spat Lower limit uncertainty in Spatial
75- 77 F3.1 arcsec E_Spat Upper limit uncertainty in Spatial
79- 98 A20 --- Match Indices that share position and redshift
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Note (1): In a vacuum, heliocentric frame (Angstroms) with an estimated
0.5Å uncertainty based on simulations.
Note (2): After removal of a 5 Angstrom FWHM instrumental resolution and
with an estimated 300km/s uncertainty.
Note (3): As measured with the curve of growth method.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- HPS [1/479] HETDEX Pilot Survey index number
5- 19 A15 --- xid Best continuum-selected counterpart
(JHHMMSSs+DDMMSS)
21- 25 F5.2 mag mag ? Counterpart R or i' band magnitude (1)
27- 30 F4.2 --- Prob Probability of counterpart association
32- 37 F6.1 0.1nm EW Rest-frame equivalent width (2)
39- 43 F5.1 0.1nm e_EW Lower limit uncertainty in EW
45- 50 F6.1 0.1nm E_EW Upper limit uncertainty in EW
52- 57 F6.1 0.1nm EWint Interpolated rest-frame equivalent width (3)
59- 64 F6.1 0.1nm e_EWint Lower limit uncertainty in EWint
66- 71 F6.1 0.1nm E_EWint Upper limit uncertainty in EWint
73- 83 A11 --- Trans Emission line transition (4)
85- 90 F6.4 --- z Estimated redshift
92- 95 F4.2 --- Lya Probability emission line is Lyα (5)
97-112 A16 --- X-ray X-ray counterpart identification
(JHHMMSSs+DDMMSS)
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Note (1): See table 2 for the Johnson or SDSS R-band filters used.
The MUNICS field, at α∼3hr, instead uses an SDSS i filter.
Note (2): For this counterpart and the selected transition based on the
R-band photometry, or the i'-band in MUNICS where no R-band is available.
Note (3): For this counterpart and the selected transition based on an
interpolation between the two nearest filters.
Note (4): Based on the EW cut and/or the presence of multiple emission lines.
Note (5): As calculated by marginalizing over all potential counterpart.
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History:
From electronic version of the journal
References:
Blanc et al. Paper II. 2011ApJ...736...31B 2011ApJ...736...31B Cat. J/ApJ/736/31
Finkelstein et al. Paper III. 2011ApJ...729..140F 2011ApJ...729..140F
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 22-Mar-2011