J/ApJ/625/6 Galaxy groups in the DEEP2 Galaxy Redshift Survey (Gerke+, 2005)
The DEEP2 Galaxy Redshift Survey: first results on galaxy groups.
Gerke B.F., Newman J.A., Davis M., Marinoni C., Yan R., Coil A.L.,
Conroy C., Cooper M.C., Faber S.M., Finkbeiner D.P., Guhathakurta P.,
Kaiser N., Koo D.C., Phillips A.C., Weiner B.J., Willmer C.N.A.
<Astrophys. J., 625, 6-22 (2005)>
=2005ApJ...625....6G 2005ApJ...625....6G
ADC_Keywords: Clusters, galaxy ; Redshifts ; Velocity dispersion
Keywords: galaxies: clusters: general - galaxies: high-redshift
Abstract:
We use the first 25% of the DEEP2 Galaxy Redshift Survey spectroscopic
data to identify groups and clusters of galaxies in redshift space.
The data set contains 8370 galaxies with confirmed redshifts in the
range 0.7≤z≤1.4, over 1°2 on the sky. Groups are identified
using an algorithm (the Voronoi-Delaunay method) that has been shown
to accurately reproduce the statistics of groups in simulated
DEEP2-like samples. We optimize this algorithm for the DEEP2 survey
by applying it to realistic mock galaxy catalogs and assessing the
results using a stringent set of criteria for measuring group-finding
success, which we develop and describe in detail here. We present the
first DEEP2 group catalog, which assigns 32% of the galaxies to 899
distinct groups with two or more members, 153 of which have velocity
dispersions above 350km/s. We provide locations, redshifts and
properties for this high-dispersion subsample. This catalog represents
the largest sample to date of spectroscopically detected groups at z∼1.
Description:
The survey consists of four fields on the sky, chosen to lie in zones
of low Galactic dust extinction. Three-band (BRI) photometry has been
obtained for each of these fields using the CFH12K camera on the
Canada-France-Hawaii Telescope (CFHT).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 33 153 Locations and properties of groups with
σ≥350km/s
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See also:
J/ApJS/142/1 : DEEP Groth Strip Survey. II. (Simard+, 2002)
J/ApJ/599/1006 : DEEP Groth Strip Survey. VII. (Kobulnicky+, 2003)
J/ApJS/157/175 : DEEP Groth Strip Survey. VIII. (Koo+, 2005)
J/ApJ/571/136 : DEEP Groth Strip survey. X. (Im+, 2002)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Hour of Right Ascension (J2000) (2) (1)
4- 5 I2 min RAm Minute of Right Ascension (J2000) (2) (1)
7- 8 I2 s RAs Second of Right Ascension (J2000) (2) (1)
10 A1 --- DE- Sign of the Declination (J2000) (2) (1)
11- 12 I2 deg DEd Degree of Declination (J2000) (2) (1)
14- 15 I2 arcmin DEm Arcminute of Declination (J2000) (2) (1)
17- 18 I2 arcsec DEs Arcsecond of Declination (J2000) (2) (1)
20- 24 F5.3 --- z Redshift (2)
26- 28 I3 km/s sigma Velocity dispersion
30- 31 I2 --- NGal Number of galaxies
33 A1 --- SDet [Y] Strong detection (3)
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Note (1): [GND2005] JHHMMSS+DDMMSS in Simbad
Note (2): Median value of all galaxies in the group.
Note (3): "Y" indicates detection in both the standard and high-purity
group catalogs.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 23-Nov-2005