Elliptical galaxy

Most elliptical galaxies are composed of older, low-mass stars, with a sparse interstellar medium, and they tend to be surrounded by large numbers of globular clusters.

Large elliptical galaxies typically have an extensive system of globular clusters.

They generally have two distinct populations of globular clusters: one that is redder and metal-rich, and another that is bluer and metal-poor.

The luminosity profiles of both elliptical galaxies and bulges are well fit by Sersic's law, and a range of scaling relations between the elliptical galaxies' structural parameters unify the population.

Observations of 46 elliptical galaxies, 20 classical bulges, and 22 pseudobulges show that each contain a black hole at the center.

Given the existence of ES galaxies with intermediate-scale disks, it is reasonable to expect that there is a continuity from E to ES, and onto the S0 galaxies with their large-scale stellar disks that dominate the light at large radii.

In recent years, evidence has shown that a reasonable proportion (~25%) of early-type (E, ES and S0) galaxies have residual gas reservoirs[25] and low-level star formation.

[26] Herschel Space Observatory researchers have speculated that the central black holes in elliptical galaxies keep the gas from cooling enough for star formation.

The giant elliptical galaxy ESO 325-4
Elliptical galaxy IC 2006 [ 13 ]
The galaxy located in the image is 4C 73.08 , a giant elliptical galaxy. [ 15 ]
Hercules A , a supergiant elliptical galaxy and also a radio galaxy . The radio lobes shown here in pink are over a million light-years across.
The brilliant central object is the supergiant elliptical galaxy SDSS J142347.87+240442.4, the dominant member of the galaxy cluster MACS J1423.8+2404. It has a diameter of 380,000 light-years. [ 20 ] Note the gravitational lensing .
NGC 3597 is the product of a collision between two galaxies. It is evolving into a giant elliptical galaxy.