Elliptical Galaxy

An Elliptical Galaxy is a type of Galaxy object representing a specific elliptical-type galaxy, or a new elliptical galaxy created by the user. Elliptical galaxies are characterized by their ellipsoidal shape, relatively featureless structure, lack of dust, and reddish color indicating the presence of older, cooler, less massive stars.

Properties

 * The Galaxy Type is located in the Galaxy tab of the Galaxy's properties panel. When the type is set to one of the elliptical types, the following property will appear:
 * The Elliptical Ratio represents the ratio of the length of the shortest axis of the galaxy to the length of its longest axis. A spherical galaxy will have an Elliptical Ratio of 1.
 * The appearance of an individual Galaxy Nebula object is controlled by the Gas Fraction, Star Fraction, Dust Fraction, and Average Star Temperature properties in the Nebula tab of the nebula's properties panel.

Models
The structure of an elliptical galaxy in simulated to create a galaxy with a spheroidal shape (i.e., an ellipsoid with two equal axes and a third, potentially smaller axis). The ratio of the smaller axis to the longest is set by the Elliptical Ratio of the galaxy. The orbits of the Galaxy Nebula objects in the galaxy are carefully calculated to constrain the nebulae within this spheroid shape.

There is minimal simulated evolution of the Galaxy Nebula objects in an elliptical galaxy. The Average Star Temperature of the nebulae in an elliptical galaxy is set to a low temperature, to simulate the cooler, older stars commonly seen in these galaxies. The Dust Fraction for all nebula is set to 0%.

Elliptical galaxies are simulated with the following subtypes, which determine the Elliptical Ratio, E: Type E0 galaxies are spherical, while type E7 galaxies are the most "squashed" in appearance.
 * E0: E = 1
 * E1: 0.95 ≤ E < 1
 * E2: 0.9 ≤ E <0.95
 * E3: 0.85 ≤ E <0.9
 * E4: 0.8 ≤ E <0.85
 * E5: 0.85 ≤ E <0.8
 * E6: 0.8 ≤ E <0.75
 * E7: 0.75 ≤ E <0.7

Limitations
Limitations