Journal article
Disturbed, diffuse, or just missing? A global study of the H I content of Hickson compact groups
Astronomy and astrophysics (Berlin), Vol.670, p.A21
02/01/2023
DOI: 10.1051/0004-6361/202244622
Abstract
Context. Hickson compact groups (HCGs) are dense configurations of four to ten galaxies, whose H I morphology appears to follow an evolutionary sequence of three phases, with gas initially confined to galaxies, then significant amounts spread throughout the intra-group medium, and finally with almost no gas remaining in the galaxies themselves. It has also been suggested that several groups may harbour a diffuse H I component that is resolved out by interferometric observations.Aims. The H I deficiency of HCGs is expected to increase as the H I morphological phase progresses along the evolutionary sequence. If this is the case, H I deficiency would be a rough proxy for the age and evolutionary state of a HCG. We aim to test this hypothesis for the first time using a large sample of HCGs and to investigate the evidence for diffuse H I in HCGs.Methods. We performed a uniform reduction of all publicly available VLA H I observations (38 HCGs) with a purpose-built pipeline that also maximises the reproducibility of this study. The resulting H I data cubes were then analysed with the latest software tools to perform a manual separation of emission features into those belonging to galaxies and those extending into the intra-group medium. We thereby classified the H I morphological phase of each group as well as quantified their H I deficiency compared to galaxies in isolation.Results. We find little evidence that H I deficiency can be used as a proxy for the evolutionary phase of a compact group in either of the first two phases, with the distribution of H I deficiency being consistent in both. However, for the final phase, the distribution clearly shifts to high H I deficiencies, with more than 90% of the expected H I content typically missing. Across all HCGs studied, we identify a few cases where there is strong evidence for a diffuse gas component in the intra-group medium, which might be detectable with improved observations. We also classify a new sub-phase where groups contain a lone H I-bearing galaxy, but are otherwise devoid of gas.Conclusions. The new morphological phase we have identified is likely the result of an evolved, gas-poor group acquiring a new, gas-rich member. The large spread of H I deficiencies in the first two morphological phases suggests that there is a broad range of initial H I content in HCGs, which is perhaps influenced by large-scale environment, and that the timescale for morphological changes is, in general, considerably shorter than the timescale for the destruction or consumption of neutral gas in these systems.
Details
- Title: Subtitle
- Disturbed, diffuse, or just missing? A global study of the H I content of Hickson compact groups
- Creators
- M. G. Jones - Instituto de Astrofísica de AndalucíaL. Verdes-Montenegro - CSIC, Inst Astrofis Andalucia, Glorieta Astron, Granada 18008, SpainJ. Moldon - Instituto de Astrofísica de AndalucíaA. Damas Segovia - CSIC, Inst Astrofis Andalucia, Glorieta Astron, Granada 18008, SpainS. Borthakur - Arizona State UniversityS. Luna - CSIC, Inst Astrofis Andalucia, Glorieta Astron, Granada 18008, SpainM. Yun - University of Massachusetts AmherstA. del Olmo - Instituto de Astrofísica de AndalucíaJ. Perea - Instituto de Astrofísica de AndalucíaJ. Cannon - Macalester CollegeD. Lopez Gutierrez - Macalester Coll, Dept Phys & Astron, 1600 Grand Ave, St Paul, MN 55105 USAM. Cluver - Swinburne University of TechnologyJ. Garrido - Instituto de Astrofísica de AndalucíaS. Sanchez - Instituto de Astrofísica de Andalucía
- Resource Type
- Journal article
- Publication Details
- Astronomy and astrophysics (Berlin), Vol.670, p.A21
- Publisher
- Edp Sciences S A
- DOI
- 10.1051/0004-6361/202244622
- ISSN
- 0004-6361
- eISSN
- 1432-0746
- Number of pages
- 47
- Grant note
- RTI2018-096228-B-C31 / National Science Foundation; National Science Foundation (NSF) the National Aeronautics and Space Administration; National Aeronautics & Space Administration (NASA) R18-RT-3082 / the U.S. Department of Energy; United States Department of Energy (DOE) grant IAA4SKA from the Economic Transformation, Industry, Knowledge and Universities Council of the Regional Government of Andalusia MCIU State Agency for Research of the Spanish MCIU "Centro de Excelencia Severo Ochoa" programme AYA2015-65973-C3-1-R / Alfred P. Sloan Foundation European Regional Development Fund from the European Union; European Union (EU); Marie Curie Actions the Japanese Monbukagakusho; Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT) FJCI-2016-29685 / Juan de la Cierva formacion fellowshipfrom the Spanish Ministerio de Ciencia, Innovacion y Universidades (MCIU) MINECO/FEDER, UE; Spanish Government SEV-2017-0709 / Max Planck Society the Higher Education Funding Council for England; UK Research & Innovation (UKRI); Higher Education Funding Council for England (HEFCE)
- Language
- English
- Date published
- 02/01/2023
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984627252202771
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