{{distinguish|Centaurus Cluster|Centaurus Supercluster}} {{Short description|Group of galaxies in the constellations Centaurus, Hydra and Virgo}} {{Galaxy cluster | name = Centaurus A/M83 group | image=300px | caption=The Centaurus A galaxy is the largest and most massive galaxy in the group | ra = {{RA|13|20}}<ref name="ned">{{cite web | title=NASA/IPAC Extragalactic Database | work=Results for NGC 5128 Group | url=http://nedwww.ipac.caltech.edu/ | access-date=2006-11-22}}</ref> | dec = {{DEC|-44|58}}<ref name="ned" /> | constellation = Hydra, Centaurus, and Virgo<ref name="NSOG">{{cite book |last= Kepple |first= George Robert |author2=Glen W. Sanner |title= The Night Sky Observer's Guide, Volume 2 |publisher= Willmann-Bell, Inc. |year= 1998 |isbn= 0-943396-60-3 |page=73 }}</ref> | member_no = 44<ref name="karachentsev2005" /> | brightest_member = Centaurus A<ref name="karachentsev2005" /> | other_names = NGC 5128 Group,<ref name="ned" /> Centaurus A Group,<ref name="ned" /> LGG 344<ref name="ned" /> }}
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 on Centaurus A, a nearby radio galaxy.<ref name="karachentsev2005">{{cite journal | author=I. D. Karachentsev | title=The Local Group and Other Neighboring Galaxy Groups | journal=Astronomical Journal | year=2005 | volume=129 | issue=1 | pages=178–188 | bibcode=2005AJ....129..178K | doi=10.1086/426368 |arxiv = astro-ph/0410065 | s2cid=119385141 }}</ref> The M83 Subgroup, at a distance of 14.9 Mly (4.56 Mpc), is centered on the Messier 83 (M83), a face-on spiral galaxy.<ref name="karachentsev2005" />
This group is sometimes identified as one group<ref name="nbg">{{cite book | author=R. B. Tully | year=1988 | title=Nearby Galaxies Catalog | edition= | publisher=Cambridge University Press | location=Cambridge | isbn=0-521-35299-1}}</ref><ref name="fouqueetal1992">{{cite journal |author1=P. Fouque |author2=E. Gourgoulhon |author3=P. Chamaraux |author4=G. Paturel | title=Groups of galaxies within 80 Mpc. II - The catalogue of groups and group members | journal=Astronomy and Astrophysics Supplement | year=1992 | volume=93 | pages=211–233 | bibcode=1992A&AS...93..211F}}</ref> and sometimes identified as two groups.<ref name="garcia1993">{{cite journal | author=A. Garcia | title=General study of group membership. II - Determination of nearby groups | journal=Astronomy and Astrophysics Supplement | year=1993 | volume=100 | pages=47–90 | bibcode=1993A&AS..100...47G}}</ref> 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.<ref name="karachentsev2005" />
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=== thumb|The galaxies NGC 5011B and NGC 5011C are imaged against a starry foreground.<ref>{{cite news|title=Don't trust your eyes|url=http://www.spacetelescope.org/images/potw1253a/|access-date=13 February 2013|newspaper=ESA/Hubble Picture of the Week}}</ref> The brightest group members were frequently identified in early galaxy group identification surveys.<ref name="nbg" /><ref name="fouqueetal1992"/> 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.<ref name="coteetal1997">{{cite journal |author1=S. Cote |author2=K. C. Freeman |author3=C. Carigan |author4=P. J. Quinn | title=Discovery of Numerous Dwarf Galaxies in the Two Nearest Groups of Galaxies | journal=Astronomical Journal | year=1997 | volume=114 | pages=1313 | bibcode=1997AJ....114.1313C | doi=10.1086/118565 |arxiv = astro-ph/9704030 |s2cid=119495338 }}</ref> 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.<ref name="banksetal1999">{{cite journal | author=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 | title=New Galaxies Discovered in the First Blind H I Survey of the Centaurus A Group | journal=Astrophysical Journal | year=1999 | volume=524 | issue=2 | pages=612–622 | bibcode=1999ApJ...524..612B | doi=10.1086/307854 |arxiv = astro-ph/9906146 | s2cid=118921426 }}</ref> 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.<ref name="minchinetal2003">{{cite journal | author=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 | title=HIDEEP - an extragalactic blind survey for very low column-density neutral hydrogen | journal=Monthly Notices of the Royal Astronomical Society | year=2003 | volume=346 | issue=3 | pages=787–802 | bibcode=2003MNRAS.346..787M | doi=10.1111/j.1365-2966.2003.07134.x | doi-access=free |arxiv = astro-ph/0308405 | s2cid=119373447 }}</ref> Several optical surveys later identified 20 more candidate objects to the group.<ref name="jerjenetal2000a">{{cite journal |author1=H. Jerjen |author2=K. C. Freeman |author3=B. Binggeli | title=Testing the Surface Brightness Fluctuations Method for Dwarf Elliptical Galaxies in the Centaurus A Group | journal=Astronomical Journal | year=2000 | volume=119 | issue=1 | pages=166–176 | bibcode=2000AJ....119..166J | doi=10.1086/301188 |arxiv = astro-ph/9912011 |s2cid=17127678 }}</ref><ref name="jerjen2002b">{{cite journal |author1=H. Jerjen |author2=K. C. Freeman |author3=B. Binggeli | title=Surface BR Photometry of Newly Discovered Dwarf Elliptical Galaxies in the Nearby Sculptor and Centaurus A Groups | journal=The Astronomical Journal | year=2000 | volume=119 | issue=2 | pages=593–608 | bibcode=2000AJ....119..593J | doi=10.1086/301216| doi-access=free }}</ref><ref name="karachentsevetal2002">{{cite journal |author1=I. D. Karachentsev |author2=M. E. Sharina |author3=A. E. Dolphin |author4=E. K. Grebel |author5=D. Geisler |author6=P. Guhathakurta |author7=P. W. Hodge |author8=V. E. Karachetseva |author9=A. Sarajedini |author10=P. Seitzer | title=New distances to galaxies in the Centaurus A group | journal=Astronomy and Astrophysics | year=2002 | volume=385 | issue=1 | pages=21–31 | bibcode=2002A&A...385...21K | doi=10.1051/0004-6361:20020042 |doi-access=free }}</ref> In 2007, the Cen A group membership of NGC 5011C was established. <ref name="sj2007">{{cite journal |author1=I. Saviane |author2=H. Jerjen | title=NGC 5011C: An Overlooked Dwarf Galaxy in the Centaurus A Group | journal=Astronomical Journal | year=2007 | volume=133 | issue=4 | pages=1756–1762 | url=http://www.iop.org/EJ/abstract/1538-3881/133/4/1756 | doi=10.1086/512157 | bibcode=2007AJ....133.1756S|arxiv = astro-ph/0701280 |s2cid=14755909 }}</ref> 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. From 2015 to 2017 a full optical survey was conducted using the Dark Energy Camera, covering 550 square degrees in the sky and doubling the number of known dwarf galaxies in this group.<ref>Müller, Oliver, Helmut Jerjen, and Bruno Binggeli. “New Dwarf Galaxy Candidates in the Centaurus Group.” Astronomy & Astrophysics 583 (November 2015): A79. https://doi.org/10.1051/0004-6361/201526748. </ref><ref>Müller, Oliver, Helmut Jerjen, and Bruno Binggeli. “New Low Surface Brightness Dwarf Galaxies in the Centaurus Group.” Astronomy & Astrophysics 597 (January 2017): A7. https://doi.org/10.1051/0004-6361/201628921. </ref> Another deep but spatially limited survey around Centaurus A revealed numerous new dwarfs.<ref>{{cite journal|doi=10.3847/0004-637X/823/1/19|title=The Extended Halo of Centaurus A: Uncovering Satellites, Streams, and Substructures|year=2016|last1=Crnojević|first1=D.|last2=Sand|first2=D. J.|last3=Spekkens|first3=K.|author3-link=Kristine Spekkens|last4=Caldwell|first4=N.|last5=Guhathakurta|first5=P.|last6=McLeod|first6=B.|last7=Seth|first7=A.|last8=Simon|first8=J. D.|last9=Strader|first9=J.|last10=Toloba|first10=E.|journal=The Astrophysical Journal|volume=823|issue=1|page=19|arxiv=1512.05366|bibcode=2016ApJ...823...19C|s2cid=119251158 |doi-access=free }}</ref>
The dwarf spheroidal galaxies of the Centaurus A group have been studied and have been found to have old, metal-poor stellar populations similar to those in the Local Group, and follow a similar metallicity–luminosity relation. One dwarf galaxy, KK98 203 (LEDA 166167), has an extended ring of Hα emission.<ref>{{cite journal|doi=10.1051/0004-6361/202039359|title=The properties of dwarf spheroidal galaxies in the Cen a group|year=2021|last1=Müller|first1=Oliver|last2=Fahrion|first2=Katja|last3=Rejkuba|first3=Marina|last4=Hilker|first4=Michael|last5=Lelli|first5=Federico|last6=Lutz|first6=Katharina|last7=Pawlowski|first7=Marcel S.|last8=Coccato|first8=Lodovico|last9=Anand|first9=Gagandeep S.|last10=Jerjen|first10=Helmut|journal=Astronomy & Astrophysics|volume=645|pages=A92|arxiv=2011.04990|s2cid=226289648 }}</ref>
===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.<ref name="karachentsev2005" /><ref name="karachentsevetal2002"/> Note that Karachentsev divides this group into two subgroups centered on Centaurus A and Messier 83. {| class="wikitable sortable" |+'''Members of the Centaurus A Subgroup''' |- ! Name ! Type<ref name="ned" /> ! R.A. (J2000)<ref name="ned" /> ! Dec. (J2000)<ref name="ned" /> ! Redshift (km/s)<ref name="ned" /> ! Apparent Magnitude<ref name="ned" /> |- | Cen 7 | Sph | {{RA|13|11|13.8}} | {{DEC|-38|53|56}} | | 17.3 |- | Cen N | | {{RA|13|48|09.1}} | {{DEC|-47|33|54}} | | 17.5 |- | Centaurus A (NGC 5128) | S0 pec | {{RA|13|25|27.6}} | {{DEC|-43|01|09}} | 547 ± 5 | 7.8 |- | Centaurus A-dE1 | dSph | {{RA|13|12|45.2}} | {{DEC|-41|49|57}} | | 19.3 |- | Centaurus A-dE3 | dE | {{RA|13|46|00.8}} | {{DEC|-36|19|44}} | | 17.1 |- | HIPASS J1337-39 | Im | {{RA|13|37|25.3}} | {{DEC|-39|53|48}} | 492 ± 4 | 16.5 |- | HIPASS J1348-37 | | {{RA|13|48|47.0}} | {{DEC|-37|58|29}} | 581 ± 8 | 16.9 |- | HIPASS J1351-47 | | {{RA|13|51|12.0}} | {{DEC|-46|58|12.9}} | 529 ± 6 | |- | KKs 51 | E/Sph | {{RA|12|44|21.5}} | {{DEC|-42|56|23}} | | 16.7 |- | KKs 55 | Sph | {{RA|13|22|12.8}} | {{DEC|-42|43|41}} | | 18.5 |- | KKs 57 | Sph | {{RA|13|41|38.1}} | {{DEC|-42|34|55}} | | 18.1 |- | LEDA 166152 | dI | {{RA|13|05|02.1}} | {{DEC|-40|04|58}} | 617 ± 4 | 16.3 |- | LEDA 166167 | dI/dSph | {{RA|13|27|27.8}} | {{DEC|-45|21|10}} | | 18 |- | LEDA 166172 | dSph | {{RA|13|43|36.0}} | {{DEC|-43|46|11}} | | 18.5 |- | LEDA 166175 | dSph | {{RA|13|46|16.8}} | {{DEC|-45|41|05}} | | 19.2 |- | LEDA 166179 | dSph | {{RA|13|48|46.4}} | {{DEC|-46|59|46}} | | 18 |- | NGC 4945 | SB(s)cd | {{RA|13|05|27.5}} | {{DEC|-49|28|06}} | 563 ± 3 | 9.3 |- | NGC 5102 | SA0 | {{RA|13|21|57.6}} | {{DEC|-36|37|49}} | 468 ± 2 | 10.4 |- | NGC 5206 | SB(r)0 | {{RA|13|33|44.0}} | {{DEC|-48|09|04}} | 571 ± 10 | 11.6 |- | NGC 5237 | I0 | {{RA|13|37|39.0}} | {{DEC|-42|50|49}} | 361 ± 4 | 13.2 |- | PGC 45104 | IABm | {{RA|13|03|33.6}} | {{DEC|-46|35|06}} | | |- | PGC 45717 | I0 pec | {{RA|13|10|32.9}} | {{DEC|-46|59|27.3}} | 1853 ± 32 | 13.3 |- | PGC 45916 | dE | {{RA|13|13|09.1}} | {{DEC|-44|53|24}} | 784 ± 31 | 14.1 |- | PGC 46663 | IBm | {{RA|13|21|47.4}} | {{DEC|-45|03|42}} | 741 | 16.1 |- | PGC 46680 | Im | {{RA|13|22|02.0}} | {{DEC|-42|32|07}} | | 16.6 |- | PGC 47171 | IABm | {{RA|13|27|37.4}} | {{DEC|-41|28|50}} | 516 ± 3 | 12.9 |- | PGC 48515 | dE | {{RA|13|42|05.6}} | {{DEC|-45|12|18}} | | 17.6 |- | PGC 48738 | IB(s)m | {{RA|13|45|00.5}} | {{DEC|-41|51|40}} | 545 ± 2 | 14.0 |- | PGC 49615 | dS0/Im | {{RA|13|57|01.4}} | {{DEC|-35|19|59}} | 561 ± 32 | 14.8 |- |}
{| class="wikitable sortable" |+'''Members of the M83 Subgroup''' |- ! Name ! Type<ref name="ned"/> ! R.A. (J2000)<ref name="ned" /> ! Dec. (J2000)<ref name="ned" /> ! Redshift (km/s)<ref name="ned" /> ! Apparent Magnitude<ref name="ned" /> |- | AM 1321-304 | dIm | {{RA|13|24|36.2}} | {{DEC|-30|58|19}} | 487 ± 1 | 16.7 |- | Centaurus A-dE2 | dE/Im | {{RA|13|21|32.4}} | {{DEC|-31|53|11}} | | 17.6 |- | Centaurus A-dE4 | dSph | {{RA|13|46|40.4}} | {{DEC|-29|58|41}} | | 19. |- | HIDEEP J1336-3321 | | {{RA|13|36|56.1}} | {{DEC|-33|21|23}} | 591 | 17.3 |- | IC 4247 | S | {{RA|13|26|44.4}} | {{DEC|-30|21|45}} | 274 ± 65 | 14.4 |- | IC 4316 | IBm pec | {{RA|13|40|18.4}} | {{DEC|-28|53|32}} | 674 ± 53 | 15.0 |- | KK 208 | dI | {{RA|13|36|35.5}} | {{DEC|-29|34|17}} | 381 | 14.3 |- | LEDA 166163 | dI | {{RA|13|21|08.2}} | {{DEC|-31|31|45}} | 571 ± 3 | 17.1 |- | LEDA 166164 | dSph | {{RA|13|22|56.2}} | {{DEC|-33|34|22}} | | 17.6 |- | M83 | SAB(s)c | {{RA|13|37|00.9}} | {{DEC|-29|51|57}} | 513 ± 2 | 8.2 |- | NGC 5253 | Im pec | {{RA|13|39|55.9}} | {{DEC|-31|38|24}} | 407 ± 3 | 10.9 |- | NGC 5264 | IB(s)m | {{RA|13|41|36.7}} | {{DEC|-29|54|47}} | 478 ± 3 | 12.6 |- | PGC 47885 | | {{RA|13|35|08.1}} | {{DEC|-30|07|03}} | 13848 | 15.8 |- | PGC 48111 | Im | {{RA|13|37|20.0}} | {{DEC|-28|02|42}} | 587 ± 3 | 15.0 |- | UGCA 365 | Im | {{RA|13|36|31.1}} | {{DEC|-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.<ref name="karachentsev2005" /> Although HIPASS J1337-39 is only listed as a possible member of the M83 Subgroup in the later list published by Karachentsev,<ref name="karachentsev2005" /> later analyses indicate that this galaxy is within the subgroup.<ref name="grossi2007">{{cite journal |author1=M. Grossi |author2=M. J. Disney |author3=B. J. Pritzl |author4=P. M. Knezek |author5=J. S. Gallagher |author6=R. F. Minchin |author7=K. C> Freeman | title=Star formation history and evolution of gas-rich dwarf galaxies in the Centaurus A group | journal=Monthly Notices of the Royal Astronomical Society | year=2007 | volume=374 | issue=1 | pages=107–130 | bibcode=2007MNRAS.374..107G | doi=10.1111/j.1365-2966.2006.11125.x|doi-access=free |arxiv = astro-ph/0611106 |s2cid=15027152 }}</ref> 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==
{{reflist}}
{{DEFAULTSORT:Centaurus A M83 Group}} Category:Centaurus A/M83 Group Category:Galaxy clusters