Editing Elliptical galaxy (section)

== General characteristics ==
[[File:Elliptical galaxy IC 2006.jpg|thumb|Elliptical galaxy [[IC 2006]]<ref>{{cite web|title=Elliptical galaxy IC 2006|url=http://www.spacetelescope.org/images/heic1508a/|website=www.spacetelescope.org|publisher=ESA/Hubble|access-date=21 April 2015}}</ref>]]

Elliptical galaxies are characterized by several properties that make them distinct from other classes of galaxy. They are spherical or ovoid masses of stars, starved of star-making gases. Furthermore, there is very little [[interstellar matter]] (neither gas nor dust), which results in low rates of [[star formation]], few [[Open cluster|open star clusters]], and few young stars; rather elliptical galaxies are dominated by [[Population II|old stellar populations]], giving them red colors. Large elliptical galaxies typically have an extensive system of [[globular cluster]]s. They generally have two distinct populations of globular clusters: one that is redder and metal-rich, and another that is bluer and metal-poor.<ref>{{cite journal|doi=10.3847/1538-3881/ac680d|title=The Ancient Globular Clusters of NGC 1291 |year=2022 |last1=Hixenbaugh |first1=Kyle |last2=Chandar |first2=Rupali |last3=Mok |first3=Angus |journal=The Astronomical Journal |volume=163 |issue=6 |page=271 |s2cid=248853311 |arxiv=2205.14047 | bibcode=2022AJ....163..271H |doi-access=free }}</ref>
[[File:Galactic fireflies.jpg|thumb|The galaxy located in the image is [[4C 73.08]], a giant elliptical galaxy.<ref>{{Cite web |last=information@eso.org |title=Galactic fireflies |url=https://esahubble.org/images/potw1246a/ |access-date=2024-09-12 |website=www.esahubble.org |language=en}}</ref>]]
The dynamical properties of elliptical galaxies and the [[Bulge (astronomy)|bulges]] of [[Disc galaxy|disk galaxies]] are similar, suggesting that they may be formed by the same physical processes, although this remains controversial. The [[Luminosity#In astronomy|luminosity]] profiles of both elliptical galaxies and bulges are well fit by [[Sersic profile|Sersic's law]], and a range of scaling relations between the elliptical galaxies' structural parameters unify the population.<ref>Graham, A.W. (2013), [http://adsabs.harvard.edu/abs/2013pss6.book...91G Elliptical and Disk Galaxy Structure and Modern Scaling Laws]</ref>

Every massive elliptical galaxy contains a [[supermassive black hole]] at its center. Observations of 46 elliptical galaxies, 20 classical bulges, and 22 pseudobulges show that each contain a black hole at the center.<ref>{{Cite journal|last1=Kormendy|first1=John|last2=Ho|first2=Luis C.|date=18 August 2013|title=Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies|journal=Annual Review of Astronomy and Astrophysics|volume=51|issue=1|pages=511–653|doi=10.1146/annurev-astro-082708-101811|issn=0066-4146|arxiv = 1304.7762 |bibcode = 2013ARA&A..51..511K |s2cid=118172025}}</ref> The mass of the black hole is tightly correlated with the mass of the galaxy,<ref>Graham, A.W. (2016), [http://adsabs.harvard.edu/abs/2016ASSL..418..263G Galaxy Bulges and Their Massive Black Holes: A Review]</ref> evidenced through correlations such as the [[M–sigma relation]] which relates the [[velocity dispersion]] of the surrounding stars to the mass of the black hole at the center.

Elliptical galaxies are preferentially found in [[galaxy clusters]] and in compact [[Galaxy group|groups of galaxies]].

Unlike flat [[spiral galaxy|spiral galaxies]] with organization and structure, elliptical galaxies are more three-dimensional, without much structure, and their stars are in somewhat random orbits around the center.