Hickson Compact Group

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Hickson Compact Group 7 image taken by the Hubble Space Telescope. This grouping is composed of one lenticular (lens-shaped) and three spiral galaxies in close proximity.[1]

A Hickson Compact Group (abbreviation: HCG) is a collection of galaxies designated as published by Paul Hickson in 1982.[2]

The most famous group on Hickson’s list of 100 objects is HCG 92, Stephan's Quintet.

Hickson Compact Groups[edit]

According to Hickson: “Most compact groups contain a high fraction of galaxies having morphological or kinematical peculiarities, nuclear radio and infrared emission, and starburst or active galactic nuclei (AGN) activity. They contain large quantities of diffuse gas and are dynamically dominated by dark matter. They most likely form as subsystems within looser associations and evolve by gravitational processes. Strong galaxy interactions result and merging is expected to lead to the ultimate demise of the group. Compact groups are surprisingly numerous, and may play a significant role in galaxy evolution.”[3]

List[edit]

HCG Galaxy count Members Notes
001
002
003
004
005
006
007
HCG 7.jpg
4 NGC 192, NGC 196, NGC 197, NGC 201 This HCG contains three spiral galaxies and a lenticular galaxy [4]
008
009
010
011
012
013
014
015
016 7 This HCG contains three starburst galaxies, two LINER galaxies, and a Seyfert 2 galaxy. [5]
017
018
019
020
021
022
023
024
025
026
027
028
029
030
031
032
033
034
035
036
037
038
039
040
041
042
043
044
045
046
047
048
049
050
051
052
053
054
055
056
057
058
059
060
061
062
063
064
065
066
067
068
069
070
071
072
073
074
075
076
077
078
079
080
081
082
083
084
085
086
087
088
089
090
091
092
Galactic clash in Stephan's Quintet.jpg
5 NGC 7317, NGC 7318A, NGC 7318B, NGC 7319, NGC 7320C Also called Stephan's Quintet, one galaxy of the sixsome, NGC 7320, is not part of the HCG, but a foreground galaxy in front of the five galaxies in the HCG. When discovered, two of the galaxies in the grouping were considered to be one galaxy, leading to the "quintet" for the 6 galaxies, but appropriate for the HCG.
093
094
095
096
097
098
099
100

Gallery[edit]

Further reading[edit]

See also[edit]

References[edit]

  1. ^ "Crowded, but Suspiciously Quiet?". Picture of the Week. ESA/Hubble. Retrieved 10 August 2011. 
  2. ^ Hickson, Paul (1982). "Systematic properties of compact groups of galaxies". Astrophysical Journal 255: 382–391. Bibcode:1982ApJ...255..382H. doi:10.1086/159838. 
  3. ^ "Compact Groups of Galaxies". Retrieved 2006-10-23. 
  4. ^ "Anne’s Picture of the Day: Hickson Compact Group 7". Anne's Astronomy News. 27 December 2012. 
  5. ^ "Hubble views a bizarre cosmic quartet". Space Daily. 22 June 2015. 
  6. ^ "A fossil in the making". ESA/Hubble Picture of the Week. Retrieved 3 July 2014. 
  7. ^ "A members-only galaxy club". ESA/Hubble Picture of the Week. Retrieved 10 December 2013. 

External links[edit]