J/A+A/474/783 Main galaxy groups from SDSS-DR5 (Deng+, 2007)
The main galaxy groups from the SDSS Data Release 5.
Deng X.-F., He J.-Z., Jiang P., Luo C.-H., Wu P.
<Astron. Astrophys. 474, 783 (2007)>
=2007A&A...474..783D 2007A&A...474..783D
ADC_Keywords: Clusters, galaxy ; Redshifts ; Velocity dispersion
Keywords: galaxies: fundamental parameters -
cosmology: large-scale structure of Universe
Abstract:
We investigate the correlations between galaxy properties and
environment. From the main galaxy sample of the SDSS Data
Release 5, we have extracted 11 163 groups at the linking length
R0=0.2x({bar}n)-1/3=1.97Mpc (where {bar}n is the mean number
density of galaxies) by the three-dimensional friends-of-friends (FOF)
algorithm, where {bar}n is the mean galaxy density, and compare basic
properties of member galaxies of main galaxy groups with those of the
main galaxy sample and isolated galaxies in each redshift bin.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 65 11163 The group catalog identified using the linking
length b=0.2
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See also:
II/276 : The SDSS Photometric Catalog, Release 5 (Adelman-McCarthy+, 2007)
http://www.sdss.org : SDSS Home Page
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Seq Sequential number
7- 9 I3 --- Rich Group richness
11- 19 F9.5 deg RAdeg Group centroid Right ascension in decimal
degrees (J2000)
21- 29 F9.5 deg DEdeg Group centroid Declination in decimal
degrees (J2000)
31- 37 F7.5 --- z Mean redshift of the group
39- 44 F6.2 km/s sigma Line-of-sight velocity dispersion of the group
46- 50 F5.2 Mpc Rad Virial radius of the group
52- 59 E8.3 solMass Mass Virial mass of the group
61- 65 F5.2 --- tcr Crossing time of the group, in units of 1/H0
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Acknowledgements:
Deng Xin-Fa, xinfadeng@163.com
(End) Patricia Vannier [CDS] 30-Aug-2007