Coma I

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Not to be confused with Coma Cluster.
Coma I Group
NGC 4414 (NASA-med).jpg
NGC 4414, a flocculent spiral galaxy in the Coma I Group
Observation data (Epoch J2000)
Constellation(s)Coma Berenices & Ursa Major
Right ascension12h 22m 19.4s[1][2]
Declination29° 53′ 47″[1][2]
Brightest memberNGC 4725[3]
Number of galaxies22–34[3][4][2][5][6]
Velocity dispersion307 km/s[7]
Redshift0.002418 (724 km/s)[1]
Distance
(co-moving)		14.52 Mpc (47.4 Mly)[7]
Binding mass2.5×1012 [3] M☉
X-ray luminosity1.6×1043 erg/s [8]
Other designations
Coma I Group,[9] NGC 4274 Group,[1] LGG 279, LGG 294,[4] NBGG 14-01,[1][5] NBGG 14-02, NBGG 14 -2 +1,[9][5] NOGG H 611, NOGG P1 631, NOGG P2 642, NOGG P2 641[2]
See also: Galaxy group, Galaxy cluster, List of galaxy groups and clusters

The Coma I Group is a group of galaxies[3][1] located about 14.5 Mpc (47.3 Mly)[7] away in the constellation Coma Berenices. The brightest member of the group is NGC 4725. The Coma I Group is rich in spiral galaxies while containing few elliptical and lenticular galaxies. Coma I lies in the foreground of the more distant Coma and Leo clusters and is located within the Virgo Supercluster.[3]

The Coma I Group is currently infalling into the Virgo Cluster and will eventually merge with it.[10]

Structure[]

The Coma I Group appears to consist of two main subgroups, a denser subgroup centered on NGC 4274[11] and NGC 4278, and looser one surrounding NGC 4565 as suggested by De Vaucouleurs.[12] However, Gregory and Thompson (1977) found no clear evidence for two distinct subgroups in Coma I. They noted a slight density enhancement around NGC 4274 with the rest of the members of Coma I uniformly distributed to the southeast of this density enhancement. They also noted a central barlike structure with a minor axis of 0.9 Mpc (2.9 Mly) and a major axis of 2.3 Mpc (7.5 Mly).[3] P. Fouque et al. and A. M. Garcia et al. both list the Coma I group consisting of two subgroups centered on NGC 4274 and NGC 4565.[6][4] Additionally, Gibson et al. suggests that another association, the Coma II Group centered on NGC 4725 is associated with the Coma I Group.[9]

Members[]

The table below lists galaxies that have been commonly and consistently identified as group members in the Nearby Galaxies Catalog,[5] the survey of Fouque et al.,[6] the Lyons Groups of Galaxies (LGG) Catalog,[4] and the three group lists created from the Nearby Optical Galaxy sample of Giuricin et al.[2]

Members of the Coma I Group
Name Type[13] R.A. (J2000)[13] Dec. (J2000)[13] Redshift (km/s)[13] Apparent Magnitude[13]
SBd? 11h 58m 56.7s +30° 24′ 43″ 760 13.1
SA(s)c 12h 04m 03.8s +31° 53′ 45″ 758 12.5
SAB(r)c 12h 09m 17.7s +29° 55′ 39″ 609 11.69
SBd 12h 12m 21.4s +29° 12′ 25″ 1127 13.59
NGC 4203 SAB0^-? 12h 15m 05.0s +33° 11′ 50″ 1086 11.8
NGC 4245 SB0/a?(r) 12h 17m 36.8s +29° 36′ 29″ 884 12.31
SB0? 12h 18m 08.2s +28° 10′ 31″ 1066 11.58
NGC 4274 (R)SB(r)ab 12h 19m 50.6s +29° 36′ 52″ 930 11.34
NGC 4278 E1-2 12h 20m 06.8s +29° 16′ 51″ 620 11.20
E0 12h 20m 20.8s +29° 18′ 39″ 1056 13.10
() (R')SAB0^+(r)? 12h 22m 26.3s +29° 12′ 33″ 913 13.22
NGC 4314 SB(rs)a 12h 22m 31.8s +29° 53′ 45″ 963 11.43
SB(rs)c? 12h 24m 11.2s +31° 31′ 19″ 1253 13.6
SABd 12h 25m 51.2s +27° 33′ 42″ 755 12.7
NGC 4414 SA(rs)c? 12h 26m 27.1s +31° 13′ 25″ 716 10.96
NGC 4448 SB(r)ab 12h 28m 15.4s +28° 37′ 13″ 661 12.00
NGC 4494 E1-2 12h 31m 24.1s +25° 46′ 31″ 1342 10.71
Scd? 12h 33m 51.1s +30° 16′ 39″ 1172 13.4
NGC 4559 SAB(rs)cd 12h 35m 57.6s +27° 57′ 36″ 807 10.46
SB(s)dm? 12h 35m 34.8s +25° 51′ 00″ 1353 13.9
NGC 4565 SA(s)b? 12h 36m 20.8s +25° 59′ 16″ 1230 10.42
NGC 4725 SAB(r)ab pec 12h 50m 26.6s +25° 30′ 03″ 1206 10.11
SBcd? pec 12h 51m 45.9s +25° 46′ 37″ 1190 12.96

Other possible member galaxies (galaxies listed in only one or two of the lists from the above references) include , , , , NGC 4150, NGC 4308, NGC 4455, , NGC 4534, NGC 4627, NGC 4631, NGC 4656, , , , , , , , and .

Nearby groups[]

The center of the Virgo Cluster (M87) lies about 3.6 Mpc (11.7 Mly) from the Coma I Group.[3]

See also[]

References[]

  1. ^ a b c d e f "Coma I Group". Retrieved 2018-05-12.
  2. ^ a b c d e G. Giuricin; C. Marinoni; L. Ceriani; A. Pisani (2000). "Nearby Optical Galaxies: Selection of the Sample and Identification of Groups". Astrophysical Journal. 543 (1): 178–194. arXiv:astro-ph/0001140. Bibcode:2000ApJ...543..178G. doi:10.1086/317070. S2CID 9618325.
  3. ^ a b c d e f g Gregory, Stephen A.; Thompson, Laird A. (April 1977). "The Coma i Galaxy Cloud". The Astrophysical Journal. 213: 345–350. Bibcode:1977ApJ...213..345G. doi:10.1086/155160. ISSN 0004-637X.
  4. ^ a b c d A. Garcia (1993). "General study of group membership. II – Determination of nearby groups". Astronomy and Astrophysics Supplement. 100: 47–90. Bibcode:1993A&AS..100...47G.
  5. ^ a b c d R. B. Tully (1988). Nearby Galaxies Catalog. Cambridge: Cambridge University Press. ISBN 0-521-35299-1.
  6. ^ a b c P. Fouque; E. Gourgoulhon; P. Chamaraux; G. Paturel (1992). "Groups of galaxies within 80 Mpc. II - The catalogue of groups and group members". Astronomy and Astrophysics Supplement. 93: 211–233. Bibcode:1992A&AS...93..211F.
  7. ^ a b c Boselli, A.; Gavazzi, G. (2009-10-21). "The HI properties of galaxies in the Coma I cloud revisited". Astronomy & Astrophysics. 508 (1): 201–207. arXiv:0909.4140. Bibcode:2009A&A...508..201B. doi:10.1051/0004-6361/200912658. ISSN 0004-6361. S2CID 14049523.
  8. ^ Garcia-Barreto, J. A.; Downes, D.; Huchtmeier, W. K. (August 1994). "H I deficiency in the Coma I cloud of galaxies" (PDF). Astronomy and Astrophysics. 288: 705–712. Bibcode:1994A&A...288..705G.
  9. ^ a b c Gibson, Brad K.; Hughes, Shaun M. G.; Stetson, Peter B.; Freedman, Wendy L.; Robert C. Kennicutt, Jr.; Mould, Jeremy R.; Bresolin, Fabio; Ferrarese, Laura; Ford, Holland C. (1999). "The Hubble Space Telescope Key Project on the Extragalactic Distance Scale. XVII. The Cepheid Distance to NGC 4725". The Astrophysical Journal. 512 (1): 48. arXiv:astro-ph/9810003. Bibcode:1999ApJ...512...48G. doi:10.1086/306762. ISSN 0004-637X. S2CID 117635398.
  10. ^ Tully, R. B.; Shaya, E. J. (June 1984). "Infall of galaxies into the Virgo cluster and some cosmological constraints". The Astrophysical Journal. 281: 31–55. Bibcode:1984ApJ...281...31T. doi:10.1086/162073. ISSN 0004-637X.
  11. ^ "Nearby Groups of Galaxies". ned.ipac.caltech.edu. Retrieved 2018-05-19.
  12. ^ Forbes, Duncan A. (October 1996). "Globular Cluster Luminosity Functions and the Hubble Constant From WFPC Imaging: Galaxies in the Coma I Cloud". The Astronomical Journal. 112: 1409. arXiv:astro-ph/9611139. Bibcode:1996AJ....112.1409F. doi:10.1086/118108. ISSN 0004-6256. S2CID 118922735.
  13. ^ a b c d e "NASA/IPAC Extragalactic Database". Results for various galaxies. Retrieved 2006-10-15.
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