What are active galaxies | Earth, Solar System and Universe.

Almost all of the galaxies have a black hole at its Center. While the black hole is active, catches and swallows all the matter that surrounds him, as a swirl. When it has no capacity to swallow more, matter continues to rotate around it, but no longer falls within. Galaxies whose black hole is still active are called Active Galaxies.
Active Galaxies are distinguished by its shape and by the large amount of radiation they emit. The black hole of the nucleus is surrounded by a bright disk of matter, dust and hot gas. Accretion disk is called, and spiral tour while emits high energy radiation. From the Poles, the black hole space launches huge jets of particles, which can measure thousands of years light.
The milky way was also an active galaxy in the past.

Types of active galaxies

Four types of active galaxies are known: the Blazars, quasars and Seyfert galaxies, the radio.
Quasars and the Blazars are the objects more distant and higher energy are known. They are thousands of millions of years Earth light. We see them as they were in the past, when galaxies were still forming. They are the most brilliant of the universe objects, even though they are so far away that their light reaches us very weakly. Almost all of the active galaxies that are known are quasars.
The radio and Seyfert galaxies are closer and also very bright objects. They emit rays X, infrared radiation and radio waves. Its radiation is so great, that they are the main source of all Cosmos radio waves.
Published for educational purposes