Elliptical Galaxies

Introduction to elliptical galaxies:

A galaxy is a massive, gravitationally bound system and it consists of stars and stellar remnants, an interstellar medium of gas and dust.  An important but poorly understood component of galaxy is tentatively dubbed dark matter. Having problem with formula for celsius to kelvin keep reading my upcoming posts, i will try to help you.

The galaxies are divided into 3 broad classes based on their visual appearance according to Hubble’s scheme as:

Elliptical galaxies
Spiral galaxies
Lenticular galaxies
Elliptical galaxies are smooth, featureless light distributions and appear as ellipses in images.

Spiral galaxies consist of a flattened disk and stars form a two-armed spiral structure with a concentration of stars at the centre is known as the bulge. And it is similar in appearance to an elliptical galaxy.

Lenticular galaxies (designated S0) consist of a bright central bulge which is surrounded by an extended, disk-like structure. These disks have no visible spiral structure and are not actively forming stars in any significant quantity.

Characteristics of Elliptical Galaxies:

An elliptical galaxy is a galaxy with an approximately ellipsoidal shape and a smooth, nearly featureless brightness profile. Elliptical galaxies do not rotate as a whole since they have little or no global angular momentum. The stars orbit the centers of these galaxies, but the orbits are statistically oriented so that only little net orbital angular momentum sums up. An elliptical galaxy contain very little or no interstellar matter, and consist of old population II stars only which appear like luminous bulges of spirals, without a disk component. In elliptical galaxies, the motion of stars is predominantly radial, where as the disks of spiral galaxies, are dominated by rotation. A very little interstellar matter (neither gas nor dust) is observed in elliptical galaxies and it results in low rates of star formation with a few open star clusters and few young stars. Also, elliptical galaxies are dominated by old stellar populations, giving them red colours. Please express your views of this topic Signs of Radiation Poisoning by commenting on blog.

Conclusion to Elliptical Galaxies:

By the Hubble classification system, elliptical galaxies ranges from E0, being nearly spherical, up to E7, which is highly elongated on the basis of their ellipticity. It is believed that many elliptical galaxies are formed due to the interaction of galaxies, resulting in a collision and merger. They grow to enormous sizes and the giant elliptical galaxies are often found near the core of large galaxy clusters. The largest galaxies are known as giant ellipticals.  It has been discovered that for some ellipticals, small disk components, and they are one end of a common scheme of galaxy forms which includes the disk galaxies.