J/A+A/618/A157 Compact Groups in SDSSDR12 (Diaz-Gimenez+, 2018)
Improving Hickson-like compact group finders in redshift surveys:
an implementation in the SDSS.
Diaz-Gimenez E., Zandivarez A., Taverna A.
<Astron. Astrophys. 618, A157 (2018)>
=2018A&A...618A.157D 2018A&A...618A.157D (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Clusters, galaxy ; Redshifts ; Velocity dispersion ;
Photometry, SDSS
Keywords: galaxies: groups: general - catalogues - methods: statistical -
methods: data analysis
Abstract:
A catalogue of compact groups identified on the SDSS DR12 is provided.
Compact Groups were identified in redshift space with a modified
Hickson-like algorithm. The catalogue comprises 462 compact groups of
which 406 clearly fulfil all the compact group requirements:
compactness, isolation and velocity concordance of all of their
members. The remaining 56 groups need further redshift information of
potentially contaminating sources.
Description:
tabled1.dat comprises 462 compact groups with four or more galaxy
members.
tabled2.dat contains information about the 2070 galaxy group members.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tabled1.dat 61 462 Table of compact groups
tabled2.dat 44 2070 Table of galaxies in compact groups
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See also:
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
VII/213 : Hickson's Compact groups of Galaxies (Hickson+ 1982-1994)
J/AJ/127/1811 : Catalog of SDSS compact groups of galaxies (Lee+, 2004)
J/MNRAS/395/255 : Compact groups of galaxies in SDSS DR6 (McConnachie+, 2009)
J/MNRAS/418/1409 : Compact groups of galaxies in SDSS DR7 (Mendel+, 2011)
J/ApJS/225/23 : Compact groups of galaxies in SDSS-DR12 (MLCG) (Sohn+, 2016)
Byte-by-byte Description of file: tabled1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- GId [1/462] Compact Group ID
5 I1 --- Ng [4/8] Number of galaxy members in the group
7- 13 F7.3 deg RAdeg Group centre Right Ascension (J2000)
16- 21 F6.3 deg DEdeg Group centre Declination (J2000)
23- 30 F8.6 --- z Group CMB redshift
32- 37 F6.3 arcmin TitaG Group angular diameter (1)
39- 44 F6.3 mag/arcsec2 mur Group surface brightness in the r band
46- 52 F7.3 km/s sigmav Group velocity dispersion in the
line of sight
54- 59 F6.3 mag rmagb r band apparent magnitude of brightest
galaxy (2)
61 A1 --- Flag [0/1] Cleaning flag (3)
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Note (1): Angular diameter of the minimum circle that encloses all the
group members.
Note (2): r band observer frame model apparent magnitude of the group brightest
galaxy, corrected for galactic extinction in AB system.
Note (3): Cleaning flag as follows:
0 = Clean groups
1 = potentially contaminated groups
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Byte-by-byte Description of file: tabled2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- GId [1/462] Compact Group ID
5 I1 --- Nm [1/8] Galaxy index
7- 13 F7.3 deg RAdeg Right Ascension (J2000)
16- 21 F6.3 deg DEdeg Declination (J2000)
23- 30 F8.6 --- z Galaxy redshift corrected to the CMB rest frame
32- 37 F6.3 mag rmag r band observer frame model apparent
magnitude (1)
39- 44 F6.3 mag gmag g band observer frame model apparent
magnitude (1)
--------------------------------------------------------------------------------
Note (1): magnitudes are corrected for galactic extinction in AB system.
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Acknowledgements:
Eugenia Diaz-Gimenez, eugeniadiazz(at)gmail.com
(End) Patricia Vannier [CDS] 23-Aug-2018