Centaurus A/M83 Group

Not to be confused with Centaurus Cluster or Centaurus Supercluster.

Centaurus A/M83 group
The Centaurus A galaxy is the largest and most massive galaxy in the group
Observation data (Epoch )
Constellation(s)	Hydra, Centaurus, & Virgo[1]
Right ascension	13h 20m[2]
Declination	-44° 58′[2]
Number of galaxies	44[3]
Brightest member	Centaurus A[3]
Other designations
NGC 5128 Group,[2] Centaurus A Group,[2] LGG 344[2]
See also: Galaxy groups and clusters, List of galaxy clusters
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The Centaurus A/M83 Group is a complex group of galaxies in the constellations Hydra, Centaurus, and Virgo. The group may be roughly divided into two subgroups. The Cen A Subgroup, at a distance of 11.9 Mly (3.66 Mpc), is centered around Centaurus A, a nearby radio galaxy.^[3] The M83 Subgroup, at a distance of 14.9 Mly (4.56 Mpc), is centered around the Messier 83 (M83), a face-on spiral galaxy.^[3]

This group is sometimes identified as one group^[4][5] and sometimes identified as two groups.^[6] Hence, some references will refer to two objects named the Centaurus A Group and the M83 Group. However, the galaxies around Centaurus A and the galaxies around M83 are physically close to each other, and both subgroups appear not to be moving relative to each other.^[3]

The Centaurus A/M83 Group is part of the Virgo Supercluster, the local supercluster of which the Local Group is an outlying member.

Members

Member identification

The brightest group members were frequently identified in early galaxy group identification surveys.^[4][5] However, many of the dwarf galaxies in the group were only identified in more intensive studies. One of the first of these identified 145 faint objects on optical images from the UK Schmidt Telescope and followed these up in hydrogen line emission with the Parkes Radio Telescope and in the hydrogen-alpha spectral line with the Siding Spring 2.3 m Telescope. This identified 20 dwarf galaxies as members of the group.^[7] The HIPASS survey, which was a blind radio survey for hydrogen spectral line emission, found five uncatalogued galaxies in the group and also identified five previously-catalogued galaxies as members.^[8] An additional dwarf galaxy was identified as a group member in the HIDEEP survey, which was a more intensive radio survey for hydrogen emission within a smaller region of the sky.^[9] Several optical surveys later identified 20 more candidate objects to the group.^[10][11][12] In 2007, the Cen A group membership of NGC 5011C was established. ^[13] While this galaxy is a well-known stellar system listed with a NGC number, its true identity remained hidden because of coordinate confusion and wrong redshifts in the literature.

Member list

The table below lists galaxies that have been identified as associated with the Centaurus A/M83 Group by I. D. Karachentsev and collaborators.^[3][12] Note that Karachentsev divides this group into two subgroups centered around Centaurus A and Messier 83.

Members of the Centaurus A Subgroup

Name	Type[2]	R.A. (J2000)[2]	Dec. (J2000)[2]	Redshift (km/s)[2]	Apparent Magnitude[2]
Cen 7	Sph	13h 11m 13.8s	-38° 53′ 56″		17.3
Cen N		13h 48m 09.1s	-47° 33′ 54″		17.5
Centaurus A (NGC 5128)	S0 pec	13h 25m 27.6s	-43° 01′ 09″	547 ± 5	7.8
Centaurus A-dE1	dSph	13h 12m 45.2s	-41° 49′ 57″		19.3
Centaurus A-dE3	dE	13h 46m 00.8s	-36° 19′ 44″		17.1
HIPASS J1337-39	Im	13h 37m 25.3s	-39° 53′ 48″	492 ± 4	16.5
HIPASS J1348-37		13h 48m 47.0s	-37° 58′ 29″	581 ± 8	16.9
HIPASS J1351-47		13h 51m 12.0s	-46° 58′ 12.9″	529 ± 6
KKs 51	E/Sph	12h 44m 21.5s	-42° 56′ 23″		16.7
KKs 55	Sph	13h 22m 12.8s	-42° 43′ 41″		18.5
KKs 57	Sph	13h 41m 38.1s	-42° 34′ 55″		18.1
LEDA 166152	dI	13h 05m 02.1s	-40° 04′ 58″	617 ± 4	16.3
LEDA 166167	dI/dSph	13h 27m 27.8s	-45° 21′ 10″		18
LEDA 166172	dSph	13h 43m 36.0s	-43° 46′ 11″		18.5
LEDA 166175	dSph	13h 46m 16.8s	-45° 41′ 05″		19.2
LEDA 166179	dSph	13h 48m 46.4s	-46° 59′ 46″		18
NGC 4945	SB(s)cd	13h 05m 27.5s	-49° 28′ 06″	563 ± 3	9.3
NGC 5102	SA0	13h 21m 57.6s	-36° 37′ 49″	468 ± 2	10.4
NGC 5206	SB(r)0	13h 33m 44.0s	-48° 09′ 04″	571 ± 10	11.6
NGC 5237	I0	13h 37m 39.0s	-42° 50′ 49″	361 ± 4	13.2
PGC 45104	IABm	13h 03m 33.6s	-46° 35′ 06″
PGC 45717	I0 pec	13h 10m 32.9s	-46° 59′ 27.3″	1853 ± 32	13.3
PGC 45916	dE	13h 13m 09.1s	-44° 53′ 24″	784 ± 31	14.1
PGC 46663	IBm	13h 21m 47.4s	-45° 03′ 42″	741	16.1
PGC 46680	Im	13h 22m 02.0s	32° 07′		16.6
PGC 47171	IABm	13h 27m 37.4s	-41° 28′ 50″	516 ± 3	12.9
PGC 48515	dE	13h 42m 05.6s	-45° 12′ 18″		17.6
PGC 48738	IB(s)m	13h 45m 00.5s	-41° 51′ 40″	545 ± 2	14.0
PGC 49615	dS0/Im	13h 57m 01.4s	-35° 19′ 59″	561 ± 32	14.8

Members of the M83 Subgroup

Name	Type[2]	R.A. (J2000)[2]	Dec. (J2000)[2]	Redshift (km/s)[2]	Apparent Magnitude[2]
AM 1321-304	dIm	13h 24m 36.2s	-30° 58′ 19″	487 ± 1	16.7
Centaurus A-dE2	dE/Im	13h 21m 32.4s	-31° 53′ 11″		17.6
Centaurus A-dE4	dSph	13h 46m 40.4s	-29° 58′ 41″		19.
HIDEEP J1336-3321		13h 36m 56.1s	-33° 21′ 23″	591	17.3
IC 4247	S	13h 26m 44.4s	-30° 21′ 45″	274 ± 65	14.4
IC 4316	IBm pec	13h 40m 18.4s	-28° 53′ 32″	674 ± 53	15.0
KK 208	dI	13h 36m 35.5s	-29° 34′ 17″	381	14.3
LEDA 166163	dI	13h 21m 08.2s	-31° 31′ 45″	571 ± 3	17.1
LEDA 166164	dSph	13h 22m 56.2s	-33° 34′ 22″		17.6
M83	SAB(s)c	13h 37m 00.9s	-29° 51′ 57″	513 ± 2	8.2
NGC 5253	Im pec	13h 39m 55.9s	-31° 38′ 24″	407 ± 3	10.9
NGC 5264	IB(s)m	13h 41m 36.7s	-29° 54′ 47″	478 ± 3	12.6
PGC 47885		13h 35m 08.1s	-30° 07′ 03″	13848	15.8
PGC 48111	Im	13h 37m 20.0s	-28° 02′ 42″	587 ± 3	15.0
UGCA 365	Im	13h 36m 31.1s	-29° 14′ 06″	573 ± 1	15.4

Additionally, ESO 219-010, PGC 39032, and PGC 51659 are listed as possibly being members of the Centaurus A Subgroup, and ESO 381-018, NGC 5408, and PGC 43048 are listed as possibly being members of the M83 Subgroup.^[3] Although HIPASS J1337-39 is only listed as a possible member of the M83 Subgroup in the later list published by Karachentsev,^[3] later analyses indicate that this galaxy is within the subgroup.^[14] Saviane and Jerjen found that NGC 5011C has an optical redshift of 647 km/s and thus is a member of the Cen A group rather than of the distant Centaurus galaxy cluster as believed since 1983.

References

1. ^ Kepple, George Robert; Glen W. Sanner (1998). The Night Sky Observer's Guide, Volume 2. Willmann-Bell, Inc.. p. 73. ISBN 0-943396-60-3. 
2. ^ ^{a b c d e f g h i j k l m n o} "NASA/IPAC Extragalactic Database". Results for NGC 5128 Group. http://nedwww.ipac.caltech.edu/. Retrieved 2006-11-22. 
3. ^ ^{a b c d e f g h} I. D. Karachentsev (2005). "The Local Group and Other Neighboring Galaxy Groups". Astronomical Journal 129 (1): 178–188. arXiv:astro-ph/0410065. Bibcode 2005AJ....129..178K. doi:10.1086/426368. 
4. ^ ^{a b} R. B. Tully (1988). Nearby Galaxies Catalog. Cambridge: Cambridge University Press. ISBN 0-521-35299-1. 
5. ^ ^{a b} 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. 
6. ^ 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. 
7. ^ S. Cote, K. C. Freeman, C. Carigan, P. J. Quinn (1997). "Discovery of Numerous Dwarf Galaxies in the Two Nearest Groups of Galaxies". Astronomical Journal 114: 1313. arXiv:astro-ph/9704030. Bibcode 1997AJ....114.1313C. doi:10.1086/118565. 
8. ^ G. D. Banks, M. J. Disney, P. M. Knezek, H. Jerjen, D. G. Barnes, R. Bhatal, W. J. G. de Blok, P. J. Boyce, R. D. Ekers, K. C. Freeman, B. K. Gibson, P. A. Henning, V. Kilborn, B. Koribalski, R. C. Kraan-Korteweg, D. F. Malin, R. F. Minchin, J. R. Mould, T. Oosterloo, R. M. Price, M. E. Putman, S. D. Ryder, E. M. Sadler, L. Staveley-Smith, I. Stewart, F. Stootman, R. A. Vaile, R. L. Webster, A. E. Wright (1999). "New Galaxies Discovered in the First Blind H I Survey of the Centaurus A Group". Astrophysical Journal 524 (2): 612–622. arXiv:astro-ph/9906146. Bibcode 1999ApJ...524..612B. doi:10.1086/307854. 
9. ^ R. F. Minchin, M. J. Disney, P. J. Boyce, W. J. G. de Blok, Q. A. Parker, G. D. Banks, K. C. Freeman, D. A. Garcia, B. K. Gibson, M. Grossi, R. F. Haynes, P. M. Knezek, R. H. Lang, D. F. Malin, R. M. Price, I. M. Stewart, A. E. Wright (2003). "HIDEEP - an extragalactic blind survey for very low column-density neutral hydrogen". Monthly Notices of the Royal Astronomical Society 346 (3): 787–802. arXiv:astro-ph/0308405. Bibcode 2003MNRAS.346..787M. doi:10.1111/j.1365-2966.2003.07134.x. 
10. ^ H. Jerjen, K. C. Freeman, B. Binggeli (2000). "Testing the Surface Brightness Fluctuations Method for Dwarf Elliptical Galaxies in the Centaurus A Group". Astronomical Journal 119 (1): 166–176. arXiv:astro-ph/9912011. Bibcode 2000AJ....119..166J. doi:10.1086/301188. 
11. ^ H. Jerjen, K. C. Freeman, B. Binggeli (2000). "Surface BR Photometry of Newly Discovered Dwarf Elliptical Galaxies in the Nearby Sculptor and Centaurus A Groups". Astronomical Society 119 (2): 593–608. Bibcode 2000AJ....119..593J. doi:10.1086/301216. 
12. ^ ^{a b} I. D. Karachentsev, M. E. Sharina, A. E. Dolphin, E. K. Grebel, D. Geisler, P. Guhathakurta, P. W. Hodge, V. E. Karachetseva, A. Sarajedini, P. Seitzer (2002). "New distances to galaxies in the Centaurus A group". Astronomy and Astrophysics 385 (1): 21–31. Bibcode 2002A&A...385...21K. doi:10.1051/0004-6361:20020042. 
13. ^ I. Saviane, H. Jerjen (2007). "NGC 5011C: An Overlooked Dwarf Galaxy in the Centaurus A Group". Astronomical Journal 133 (4): 1756–1762. arXiv:astro-ph/0701280. Bibcode 2007AJ....133.1756S. doi:10.1086/512157. http://www.iop.org/EJ/abstract/1538-3881/133/4/1756. 
14. ^ M. Grossi, M. J. Disney, B. J. Pritzl, P. M. Knezek, J. S. Gallagher, R. F. Minchin, K. C> Freeman (2006). "Star formation history and evolution of gas-rich dwarf galaxies in the Centaurus A group". Monthly Notices of the Royal Astronomical Society 374 (1): 107–130. arXiv:astro-ph/0611106. Bibcode 2007MNRAS.374..107G. doi:10.1111/j.1365-2966.2006.11125.x.