J/A+A/691/A6 Compact groups of galaxies in GAMA (Zandivarez+, 2024)
Compact groups of galaxies in GAMA.
Probing the densest minor systems at intermediate redshifts.
Zandivarez A., Diaz-Gimenez E., Taverna A., Rodriguez F., Merchan M.
<Astron. Astrophys. 691, A6 (2024)>
=2024A&A...691A...6Z 2024A&A...691A...6Z (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Galaxies, photometry ; Optical
Keywords: methods: data analysis - methods: statistical - catalogs -
galaxies: groups: general
Abstract:
Over the years, several compact group catalogues have been constructed
using different methods, but most of them are not
deep enough to go beyond the very local universe with a high level of
redshift completeness.
We proposed to build a statistically reliable sample of compact groups
to study the influence of its inner extreme environment
at intermediate redshifts.
We adopted the Galaxy And Mass Assembly redshift survey as a parent
galaxy catalogue, complemented with a small sample of galaxies from
the Sloan Digital Sky Survey, to identify compact groups using
Hickson-like criteria. We explored the parameter space to perform
several identifications to build samples with different
characteristics. Particularly, we reduced the maximum galaxy
separation in the line-of-sight to 500km/s and we implemented
different magnitude ranges to define membership: 3, 2 or 1 magnitude
difference between the brightest galaxy and the other members, and no
restriction at all. For comparison, we used control samples extracted
from a catalogue of loose groups to contrast properties with the
compact groups.
We build five considerably large compact group samples, ranging from
more than 400 up to roughly 2400 systems, and maximum redshifts from
0.2 to 0.4, depending on the selected parameters. The overall
properties of each sample are in agreement with previous findings.
Moreover, there is a tendency of compact groups to have a larger
fraction of quenched galaxies than control loose groups, mainly for
low stellar mass galaxies in compact groups with small crossing times.
In addition, ∼45% of compact groups are embedded in loose galaxy
systems and display the highest compactness, lowest crossing times and
brightest first-ranked galaxies compared to compact groups considered
non-embedded or isolated. There is almost no evolution of compact
group properties with redshift.
Our results confirm previous findings that postulate compact groups as
one of the suitable places to study the suppression of the star
formation rate in galaxies primarily due to galaxy interactions. These
new Hickson-like compact group samples will be valuable to deepen the
analysis of these peculiar galaxy systems in a redshift regime poorly
explored so far.
Description:
We adopted the GAMA redshift survey as a parent catalogue,
complemented with galaxies from the SDSS, to identify compact groups
using Hickson-like criteria. We explored the parameter space to
perform several identifications: we reduced the maximum galaxy
separation in the line-of-sight to 500km/s and we implemented
different magnitude ranges to define membership. We build five
considerably large compact group samples, ranging from more than 400
up to ∼2400 systems, and maximum redshifts from 0.2 to 0.4. We also
constructed a catalogue of loose groups in the same parent catalogue
following Rodriguez & Merchan (2020A&A...636A..61R 2020A&A...636A..61R).
Tables A1 and A2 correspond to different samples of compact groups. The
samples are labelled according to the parameters used in the
identification (m#v##): m# denotes the magnitude range (0,1,2,3),
v## denotes the maximum radial velocity difference in units of 100km/s
(5, 10). Tables A3 and A4 comprise the sample of loose groups.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 96 4632 Compact groups in the 5 samples
tablea2.dat 56 14711 Galaxies in compact groups in the 5 samples
tablea3.dat 50 94423 Loose groups
tablea4.dat 51 134333 Galaxies in loose groups
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See also:
J/MNRAS/413/971 : Galaxy And Mass Assembly (GAMA) DR1 (Driver+, 2011)
J/MNRAS/452/2087 : Galaxy And Mass Assembly (GAMA) DR2 (Liske+, 2015)
J/MNRAS/474/3875 : Galaxy And Mass Assembly (GAMA) DR3 (Baldry+, 2018)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Sample Sample (G1)
7- 10 I4 --- GId Compact Group ID within the sample
12 I1 --- N [3-9] Number of galaxy members in the group
14- 20 F7.3 deg RAdeg Group centre Right Ascension (J2000)
22- 27 F6.3 deg DEdeg Group centre Declination (J2000)
29- 36 F8.6 --- z Median biweighted Group CMB redshift
38- 44 F7.3 kpc Rij Median projected galaxy separation
(in kpc/h unit)
46- 51 F6.3 mag/arcsec2 mu Group surface brightness in the r band
53- 60 F8.3 km/s sigmav Group radial velocity dispersion
62- 66 F5.3 --- tcr Dimensionless crossing time
68- 73 F6.3 mag rbmag Brightest galaxy r-band apparent
magnitude (G2)
75- 80 F6.3 mag rfmag Faintest galaxy r-band apparent
magnitude (G2)
82- 88 F7.3 --- r1MAG Brightest galaxy rest-frame absolute
magnitude (in mag-5log(h) units)
90- 96 F7.3 --- r2MAG 2nd brightest galaxy rest-frame absolute
magnitude (in mag-5log(h) units)
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- Sample Sample (G1)
7- 10 I4 --- GId Compact Group ID within the sample
12- 18 F7.3 deg RAdeg Galaxy Right Ascension (J2000)
20- 25 F6.3 deg DEdeg Declination (J2000)
27- 34 F8.6 --- z Galaxy CMB redshift
36- 41 F6.3 mag rmag r-band apparent magnitude (G2)
43- 48 F6.3 mag gmag g-band apparent magnitude (G2)
50- 56 F7.3 --- rMAG r-band rest-frame absolute magnitude
(in mag-5log(h) unit)
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Byte-by-byte Description of file: tablea3.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- GId Loose Group ID
7- 9 I3 --- N [1/256] Number of galaxy members
11- 17 F7.3 deg RAdeg Group centre Right Ascension (J2000)
19- 24 F6.3 deg DEdeg Group centre Declination (J2000)
26- 33 F8.6 --- z Median biweighted Group CMB redshift
35- 43 E9.3 Msun Mass Group Mass (in Msun/h unit)
45- 50 F6.3 mag rmag Brightest galaxy r-band apparent magnitude (G2)
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Byte-by-byte Description of file: tablea4.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- GId Loose Group ID
7- 13 F7.3 deg RAdeg Galaxy Right Ascension (J2000)
15- 20 F6.3 deg DEdeg Galaxy Declination (J2000)
22- 29 F8.6 --- z Galaxy CMB redshift
31- 36 F6.3 mag rmag r-band apparent magnitude (G2)
38- 43 F6.3 mag gmag g-band apparent magnitude (G2)
45- 51 F7.3 --- rMAG r-band rest-frame absolute magnitude
(in mag-5log(h) unit)
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Global notes:
Note (G1): Samples as follows:
m0V5 = magnitude range between the brightest galaxy and the other members 0,
maximum radial velocity difference 500km/s, 2356 groups
m1V5 = magnitude range between the brightest galaxy and the other members 1,
maximum radial velocity difference 500km/s, 612 groups
m2V5 = magnitude range between the brightest galaxy and the other members 2,
maximum radial velocity difference 500km/s, 759 groups
m3V10 = magnitude range between the brightest galaxy and the other members 3,
maximum radial velocity difference 1000km/s, 438 groups
m3V5 = magnitude range between the brightest galaxy and the other members 4,
maximum radial velocity difference 500km/s, 467 groups
Note (G2): r-band observer frame model apparent magnitude corrected for
galactic extinction in AB system.
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Acknowledgements:
Ariel Zandivarez, ariel.zandivarez(at)unc.edu.ar
(End) Patricia Vannier [CDS] 19-Aug-2024