Issue |
A&A
Volume 691, November 2024
|
|
---|---|---|
Article Number | A6 | |
Number of page(s) | 15 | |
Section | Extragalactic astronomy | |
DOI | https://doi.org/10.1051/0004-6361/202451471 | |
Published online | 25 October 2024 |
Compact groups of galaxies in GAMA
Probing the densest minor systems at intermediate redshifts
1
Universidad Nacional de Córdoba (UNC), Observatorio Astronómico de Córdoba (OAC), Córdoba, Argentina
2
CONICET. Instituto de Astronomía Teórica y Experimental (IATE), Laprida 854, X5000BGR Córdoba, Argentina
3
Instituto de Astronomía, UNAM, Apdo. Postal 106, Ensenada, 22800 B.C., Mexico
⋆ Corresponding author; ariel.zandivarez@unc.edu.ar
Received:
12
July
2024
Accepted:
14
August
2024
Context. Several compact group catalogues have been constructed over the years 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.
Aims. We build a statistically reliable sample of compact groups to study the influence of its inner extreme environment at intermediate redshifts.
Methods. We adopted the Galaxy And Mass Assembly (GAMA) 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, with which we built samples with different characteristics. Particularly, we reduced the maximum galaxy separation in the line of sight to 500 km s−1, and we implemented different magnitude ranges to define membership: a difference between three, two, or one magnitudes 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 compare their properties with those of the compact groups.
Results. We built 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 agree with previous findings. Moreover, compact groups have a tendency for a larger fraction of quenched galaxies than control loose groups, mainly for galaxies with a low stellar mass in compact groups with short crossing times. In addition, ∼45% of the compact groups are embedded in loose galaxy systems and are highly compact, have the shortest crossing times, and the brightest first-ranked galaxies than compact groups that are considered to be non-embedded or isolated. The compact group properties almost do not evolve at all with redshift.
Conclusions. Our results confirm previous findings that postulated that compact groups are one of the suitable places in which the suppression of the star formation rate in galaxies that is primarily due to galaxy interactions can be studied. These new Hickson-like compact group samples will be valuable to deepen the analysis of these peculiar galaxy systems in a redshift regime that was poorly explored so far.
Key words: methods: data analysis / methods: statistical / catalogs / galaxies: groups: general
© The Authors 2024
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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