J/ApJS/246/12 Compact groups of galaxies in SDSS & LAMOST. I. (Zheng+, 2020)
Compact groups of galaxies in Sloan Digital Sky Survey and LAMOST spectral
survey.
I. The Catalogs.
Zheng Y.-L., Shen S.-Y.
<Astrophys. J. Suppl. Ser., 246, 12 (2020)>
=2020ApJS..246...12Z 2020ApJS..246...12Z
ADC_Keywords: Galaxies, spectra; Surveys; Optical; Redshifts; Photometry, SDSS
Keywords: Galaxy groups ; Hickson compact group ; Redshift surveys ;
Galaxy environments
Abstract:
A compact group (CG) is a kind of special galaxy system where the
galaxy members are separated at distances of the order of galaxy size.
The strong interaction between the galaxy members makes CGs ideal labs
for studying the environmental effects on galaxy evolution. The
traditional photometric selection algorithm biases against the CG
candidates at low redshifts, while the spectroscopic identification
technique is affected by the spectroscopic incompleteness of sample
galaxies and typically biases against the high redshift candidates. In
this study, we combine these two methods and select CGs in the main
galaxy sample of the Sloan Digital Sky Survey, where we also have
taken the advantages of the complementary redshift measurements from
the LAMOST spectral and GAMA surveys. We have obtained the largest and
most complete CG samples to date. Our samples include 6144 CGs and
8022 CG candidates, which are unique in the studies of the nature of
the CGs and the evolution of the galaxies inside.
Description:
In this paper, we select the compact groups (CGs) in the largest and
most complete low redshift spectroscopic galaxy sample, the SDSS main
galaxy sample (MGS; Sohn+ 2016, J/ApJS/225/23), which is defined as
the galaxies with r-band Galactic extinction corrected Petrosian
magnitude r≤17.77. We also impose a bright-end limit r≥14.00 on our
sample galaxies. We take the basic photometric parameters and
spectroscopic redshifts of the MGS from the NYU Value-Added Galaxy
Catalog (Blanton+ 2005AJ....129.2562B 2005AJ....129.2562B), which is based on
DR7 of the SDSS (see II/294).
We matched the photometric MGS sample with the SDSS-DR14, the most
up-to-date LAMOST data release (DR7 V0, until March of 2019) and the
GAMA-DR2 (Liske+ 2015, J/MNRAS/452/2087) and obtained a significant
amount of extra redshifts.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 62 6144 *Catalog of the compact group of galaxies ("cCGs")
table4.dat 56 8022 *Catalog of the possible compact groups ("pCGs");
updated version from the author
table5.dat 48 19465 Basic parameters of the member galaxies of each cCG
table6.dat 48 26652 Basic parameters of member galaxies of each groups
identified in pCGs; updated version from the author
table8.dat 51 76 Basic parameters of bright galaxies
within 3θG of each cCGs
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Note on table3.dat and table4.dat: Compact group (CG) candidates have been
separated according to the redshift status of galaxies.
One catalog is the conservative sample of CGs ("cCGs") with
spectroscopic redshifts for all the members and the nearest neighbor,
the others with assumed redshifts are named as possibly CGs ("pCGs").
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See also:
VII/85 : Hickson Compact Groups of Galaxies (Hickson 1982)
VII/86 : Groups of Galaxies. I. Nearby Groups (Huchra+ 1982)
VII/213 : Hickson's Compact groups of Galaxies (Hickson+ 1982-1994)
VII/221 : PSCz catalog (Saunders+, 2000)
VII/250 : The 2dF Galaxy Redshift Survey (2dFGRS) (2dFGRS Team, 1998-2003)
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
V/146 : LAMOST DR1 catalogs (Luo+, 2015)
V/153 : LAMOST DR4 catalogs (Luo+, 2018)
V/164 : LAMOST DR5 catalogs (Luo+, 2019)
J/ApJ/399/353 : Radial velocities in Hickson compact groups (Hickson+ 1992)
J/AJ/125/1660 : Distant compact groups from DPOSS (Iovino+, 2003)
J/AJ/127/1811 : Catalog of SDSS compact groups of galaxies (Lee+, 2004)
J/AN/327/365 : Clusters and groups of galaxies in 2dF (Tago+, 2006)
J/ApJS/167/1 : Galaxy groups and clusters from SDSS (Berlind+, 2006)
J/ApJ/655/790 : Groups of galaxies in 2MASS survey (Crook+, 2007)
J/ApJ/685/235 : Host and companion galaxies in the SDSS (Patton+, 2008)
J/MNRAS/395/255 : Compact groups of galaxies in SDSS DR6 (McConnachie+, 2009)
J/AJ/139/1857 : Sample of major galaxy pairs at z=0.08-0.38 (Woods+, 2010)
J/MNRAS/426/296 : Compact Groups of galaxies from 2MASX (Diaz-Gimenez+, 2012)
J/A+A/540/A106 : SDSS-DR8 groups and clusters of galaxies (Tempel+, 2012)
J/AJ/149/171 : 2MASS galaxy group catalog (Tully, 2015)
J/MNRAS/452/2087 : Galaxy And Mass Assembly (GAMA): DR2 (Liske+, 2015)
J/other/RAA/16.C7 : LAMOST-SDSS galaxy pairs (Shen+, 2016)
J/ApJS/225/23 : Compact groups of gal. from SDSS-DR12 (MLCG) (Sohn+, 2016)
J/A+A/588/A14 : Friends-of-friends galaxy group finder (Tempel+, 2016)
J/A+A/596/A14 : Group catalogues of the local universe (Saulder+, 2016)
J/A+A/602/A100 : Merging groups & clusters from SDSS (Tempel+, 2017)
J/A+A/618/A81 : Bayesian group finder applied to 2MRS data (Tempel+, 2018)
J/A+A/618/A157 : Compact Groups in SDSSDR12 (Diaz-Gimenez+, 2018)
http://www.sdss.org/ : The SDSS home page
http://www.lamost.org/ : The LAMOST home page
http://www.gama-survey.org/ : The GAMA survey home page
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- ID Group identifier ("cCGs-0001" to "cCGs-6144")
11- 18 F8.4 deg RAdeg Right Ascension (J2000)
20- 27 F8.4 deg DEdeg [-19.6/68.5] Declination (J2000)
29 I1 --- N [3/8] Richness
31- 37 F7.5 --- zg [0.01/0.21] Redshift (zg)
39- 43 F5.3 arcmin Rad [0.05/3.5] Angular radius (θG)
45- 50 F6.3 mag/arcsec2 mu [18.3/26] Surface brightness (µ)
52- 58 F7.3 km/s sig [3.2/985.5] velocity dispersion (σLOS)
60- 62 F3.1 --- Delm3 [0/1] The magnitude range Δm≤3
criterion flag (1=True); see Section 5.1
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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- 9 A9 --- ID Group identifier ("pCGs-0001" to "pCGs-8022")
11- 18 F8.4 deg RAdeg Right Ascension (J2000)
20- 27 F8.4 deg DEdeg [-11.2/70] Declination (J2000)
29 I1 --- N [3/6] Richness
31- 37 F7.5 --- zg [0.01/0.21] Redshift (zg)
39- 43 F5.3 arcmin Rad [0.04/3] Angular radius (θG)
45- 50 F6.3 mag/arcsec2 mu [17.9/26.4] Surface brightness (µ)
52- 52 I1 --- Case [1/3] Classification of uncertain case
as described in Figure 3 (1)
54- 56 F3.1 --- Delm3 [0/1] The magnitude range Δm≤3
criterion flag (1=True); see Section 5.1
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Note (1): Cases for compact group candidates ("pCG") as in Figure 3:
1 = meets all CG criteria except that at least one member galaxy lacks
spectroscopic redshifts (6790 occurrences).
2 = meets all CG criteria redshifts except that there are galaxies without
spectroscopic redshift inside the isolation ring (458 occurrences).
3 = Combination of Cases 1 and 2 (774 occurrences).
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Byte-by-byte Description of file: table[56].dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- ID Group identifier
11- 13 I3 --- Gal [-99/8] Member identifier (1)
15- 22 F8.4 deg RAdeg Right Ascension in decimal degrees (J2000)
24- 31 F8.4 deg DEdeg [-19.6/70] Declination in decimal degrees (J2000)
33- 39 F7.5 --- z [0/0.21] Redshift
41- 46 F6.3 mag rmag [14/17.8] Apparent r band magnitude
48 I1 --- r_z [0/4]? Source of z (2)
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Note (1):
-99 = An 'interloper' of Case 2 and 3 pCGs.
Note (2): Redshift source as follows:
0 = no redshift measurement;
1 = SDSS;
2 = LAMOST;
3 = GAMA (Liske+ 2015, J/MNRAS/452/2087);
4 = VAGC (the NYU Value-Added Galaxy Catalog; Blanton+ 2005AJ....129.2562B 2005AJ....129.2562B)
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- ID Group identifier
11- 18 F8.4 deg RAdeg Right Ascension in decimal degrees (J2000)
20- 26 F7.4 deg DEdeg [-19.6/70] Declination in decimal degrees (J2000)
28- 34 F7.5 --- z [0.0112/0.052]? Redshift of the galaxy
36- 41 F6.3 mag rmag [12.2/14] Galactic extinction corrected
r-band Petrosian magnitude of the galaxy
43- 49 F7.5 --- zg [0.0113/0.052] Redshift of corresponding cCG
51 I1 --- Loc [1/2] Projected location of the bright galaxies
in their corresponding cCGs (1)
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Note (1): : Location of the bright galaxies in their corresponding compact
group:
1 = within the smallest enclosed circle;
2 = within the isolation ring.
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History:
From electronic version of the journal for Tables 3, 5 and 8.
Tables 4 and 6 sent by the author.
Acknowledgements:
Shiyin Shen [ssy at shao.ac.cn]
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 06-Apr-2020