Fanaroff–Riley classification

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== Fanaroff–Riley Classification ==

The Fanaroff–Riley classification is a system used in astronomy to categorize radio galaxies based on their radio luminosity and the morphology of their radio jets. This classification was first introduced by Bernard Fanaroff and Julia Riley in 1974.

Classification Types[edit | edit source]

The Fanaroff–Riley classification divides radio galaxies into two main types:

Fanaroff–Riley Type I (FR I)[edit | edit source]

Fanaroff–Riley Type I radio galaxies are characterized by their lower radio luminosity. The radio jets in FR I galaxies are brightest near the galactic core and become fainter as they move outward. These jets often appear to be more diffuse and less collimated compared to FR II jets. FR I galaxies are typically found in rich galaxy clusters and are often associated with elliptical galaxies.

Fanaroff–Riley Type II (FR II)[edit | edit source]

Fanaroff–Riley Type II radio galaxies have higher radio luminosity. The radio jets in FR II galaxies are brightest at the edges, where they terminate in bright radio lobes. These jets are usually more collimated and can extend over large distances. FR II galaxies are often found in less dense environments compared to FR I galaxies and are also associated with elliptical galaxies.

Significance[edit | edit source]

The Fanaroff–Riley classification is significant because it provides insights into the physical processes governing the formation and evolution of radio jets in galaxies. The differences between FR I and FR II galaxies are thought to be related to the central black hole's properties, the accretion rate, and the surrounding interstellar medium.