ESO 444-46

{{Short description|Galaxy in the constellation Centaurus}} {{Infobox Galaxy | name = ESO 444-46 | image = File:ESO 444-46.jpg | caption = [[Hubble Space Telescope|HST]] image of the elliptical galaxy ESO 444-46. | epoch = [[J2000]] | type = cD;E+4;BrClG<ref name=ned>{{cite web |url=https://ned.ipac.caltech.edu/cgi-bin/objsearch?objname=ESO%20444-46&extend=no&hconst=67.74&omegam=0.3089&omegav=0.6911&corr_z=1&out_csys=Equatorial&out_equinox=J2000.0&obj_sort=RA+or+Longitude&of=pre_text&zv_breaker=30000.0&list_limit=5&img_stamp=YES |title=Detailed Information for Object ESO 444- G 046 |work=[[NASA/IPAC Extragalactic Database]] |access-date=2018-04-12}}</ref> | constellation name = [[Centaurus (constellation)|Centaurus]] | ra = {{RA|13|27|56.9s}}<ref name="ned" /> | dec = {{DEC|-31|29|44}}<ref name="ned" /> | dist_ly = {{cvt|200.8|+/-|14.1|Mpc|Mly|sigfig=4|abbr=on|lk=on|order=flip}}{{hub|0.6774}} {{small|(''Comoving'')}}<ref name=ned/> {{cvt|667|Mly|Mpc|sigfig=4|abbr=on|lk=on}}{{hub|0.6774}} {{small|(''[[Light-travel distance|Light-travel]]'')}} | group_cluster = [[Abell 3558]] | z = {{val|0.046902|0.000070}}<ref name="ned" /> | h_radial_v = {{val|14061|21|u=km/s|fmt=commas}}<ref name=ned /> | gal_v = {{val|13921|22|u=km/s|fmt=commas}}<ref name=ned /> | appmag_v = 12.6<ref name="ned" /> | size = {{cvt|205.64|x|117.22|kpc|ly|sigfig=5|abbr=on|lk=on|disp=x| (|)|order=flip}} {{small|(''[[Galaxy#Isophotal diameter|diameter]]; 27.0 B-mag arcsec{{sup|−2}}'')}}<ref name=ned/>{{efn|name=Size correction|The quick-look major axis physical diameters given by NED of {{convert|183.41|x|104.55|kpc|ly|sigfig=3|abbr=off}} and {{convert|123.32|x|86.32|kpc|ly|sigfig=3|abbr=off}} were based on a distance estimate of {{convert|179.0|+/-|45.255|Mpc|e6ly|sigfig=4|abbr=off}}. The quoted diameters in this infobox were based on NED's provided scale "[[Virgo Supercluster|Virgo]] + [[Great Attractor|GA]] + [[Shapley Supercluster|Shapley]]" of 973 parsecs/arcsec multiplied by the given angular diameters.}} {{cvt|138.26|x|96.78|kpc|ly|sigfig=5|abbr=on|lk=on|disp=x| (|)|order=flip}} {{small|(''[[Galaxy#Isophotal diameter|diameter]]; "total" magnitude'')}}<ref name="ned"/>{{efn|name=Size correction}} | size_v = {{Val|1.7|×|1.2|ul=arcminute}}<ref name="ned" /> | notes = Large globular cluster population | names = {{odlist|name=ESO 444- G 046<ref name="ned" />|MCG=−05-32-026<ref name="ned" />|PGC=047202<ref name="ned" />|name2=Shapley 8-1<ref name="ned" />}} }}

'''ESO 444-46''' ('''Shapley 8-1''', '''A3558-M1 or ESO 444-G 046''') is a class E4 [[cD galaxy|supergiant]] [[elliptical galaxy]];<ref name="User 2018">{{Cite web|url=http://chart32.de/component/k2/galaxies/central-shapley-supercluster-abell-3558|title=Central Shapley Supercluster (Abell 3558)|website=chart32.de|access-date=2018-04-12}}</ref> the dominant and brightest member of the Abell 3558 [[galaxy cluster]] around {{convert|200.8 ± 14.1|Mpc|e6ly|sigfig=4|abbr=off|lk=on}} away in the [[constellation]] [[Centaurus (constellation)|Centaurus]].<ref name="User 2018" /><ref>{{Cite journal|last1=Loubser|first1=S. I.|last2=Sansom|first2=A. E.|last3=Sánchez-Blázquez|first3=P.|last4=Soechting|first4=I. K.|last5=Bromage|first5=G. E.|date=2008-12-11|title=Radial kinematics of brightest cluster galaxies|journal=Monthly Notices of the Royal Astronomical Society|language=en|volume=391|issue=3|pages=1009–1028|doi=10.1111/j.1365-2966.2008.13813.x|doi-access=free |issn=0035-8711|arxiv=0808.1521|bibcode=2008MNRAS.391.1009L|s2cid=9364497}}</ref><ref>{{Cite news|url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=ESO+444-46&submit=submit+id|title=ESO 444-46|access-date=2018-04-12}}</ref><ref name=ned/> It lies within the core of the massive [[Shapley Supercluster]] (Shapley Concentration), one of the closest neighboring [[supercluster]]s.<ref>{{Cite web|url=http://www.atlasoftheuniverse.com/superc/shapley.html|title=The Shapley Supercluster|website=www.atlasoftheuniverse.com|access-date=2018-04-12}}</ref> It is one of the [[List of largest galaxies|largest galaxies]] in the [[observable universe|local universe]], and possibly contains one of the [[List of most massive black holes|most massive black holes]] known. The [[black hole]]'s mass is very uncertain of {{Val|26.9|50.7|26.4|u=billion}} [[solar mass]]es ({{Solar mass|link=yes}}), (with estimates ranging from as low as {{Solar mass|link=yes|501 million}}, to as high as {{Solar mass|77.6 billion}}).<ref name=dullo2019>{{cite journal|last=Dullo|first=B.T.|title=The Most Massive Galaxies with Large Depleted Cores: Structural Parameter Relations and Black Hole Masses|journal=The Astrophysical Journal|date=22 November 2019|volume=886|issue=2|page=80|arxiv=1910.10240|bibcode=2019ApJ...886...80D|doi=10.3847/1538-4357/ab4d4f|s2cid=204838306 |doi-access=free }}</ref><ref name=dullo2021a>{{cite journal|last1=Dullo|first1=B.T.|last2=de Paz|first2=A.G.|last3=Knapen|first3=J.H.|title=Ultramassive black holes in the most massive galaxies: MBH−σ versus MBH−Rb|journal=The Astrophysical Journal|date=18 February 2021|volume=908|issue=2|page=134|arxiv=2012.04471|bibcode=2021ApJ...908..134D|doi=10.3847/1538-4357/abceae|s2cid=227745078 |doi-access=free }}</ref>

==Physical characteristics==

===Globular clusters===

ESO 444-46 has an estimated population of about 27,000 [[globular clusters]] which may be one of the largest populations ever studied. This is in contrast to 15,000 globular clusters in [[Messier 87]], and 200 in the [[Milky Way]]. However, this large number may be due to the addition of [[Intracluster globular clusters]] since the galaxy lies about 1 arcmin of the center of Abell 3558.<ref>{{Cite web|url=https://research.libraries.wsu.edu:8443/xmlui/bitstream/handle/2376/3008/BarberDeGraaff_wsu_0251E_10242.pdf?sequence=1&isAllowed=y|title=A Study of Globular Cluster Systems in the Shapley Supercluster Region with the Hubble Space Telescope|last=Barber DeGraaff|first=Regina Grace|date=August 2011|website=Washington State University Libraries|access-date=2018-04-12|archive-date=2021-09-09|archive-url=https://web.archive.org/web/20210909232500/https://research.libraries.wsu.edu:8443/xmlui/bitstream/handle/2376/3008/BarberDeGraaff_wsu_0251E_10242.pdf?sequence=1&isAllowed=y|url-status=dead}}</ref>

===Supermassive black hole===

A calculation using the spheroidal luminosity method by estimating the stellar density of the central region using its brightness, yielded a initial mass of 77.6 billion solar masses (with the range being {{Solar mass|22 billion}} to {{Solar mass|270 billion}}).<ref name=dullo2019/><ref name=dullo2021a/> This would make it one of the [[List of most massive black holes|most massive black holes]] known – nearly twelve times the mass of the black hole in Messier 87, and 18,000 times more massive than [[Sagittarius A*]] (Sgr A*), the Milky Way's central black hole. A black hole of this mass has a [[Schwarzschild radius]] of 1,530 [[astronomical unit|AU]] (about 461 billion km in diameter) or 102 times the distance between [[Neptune]] and the [[Sun]].

Alternative calculations using the [[M-sigma relation]] and the newer core break radius method yielded estimates of {{Solar mass|501 million}} and {{Solar mass|{{Val|26.9|50.7|26.4|u=billion}}}}, respectively.<ref name=dullo2019 /><ref name=dullo2021a />

== See also == * [[List of galaxies]] * [[List of nearest galaxies]] * [[List of NGC objects (4001–5000)]] * [[List of spiral galaxies]] * [[NGC 4889]] * [[NGC 4874]] * [[IC 1101]]

==Notes== {{notelist}}

== References == {{Reflist}}

==External links== {{WikiSky}}

[[Category:Centaurus]] [[Category:Elliptical galaxies]] [[Category:ESO objects|444-46]] [[Category:Principal Galaxies Catalogue objects|047202]] [[Category:Shapley Supercluster]]