The answer is Accretion of material by the supermassive black holes located in the galactic cores and this is the cause of intense luminosity of the galaxies that are active like seyferts as well as quasars.Hope this is the answer and would help.
Accretion of material due to supermassive black holes in galactic cores leads to intense active galaxies luminosity.
<h2>Explanation:</h2>
The center of the galaxies has a high luminosity as compared to other parts postulated to be emitted by something other than the stars because of its intense luminosity. They are electromagnetic radiation source which is useful for discovering objects from outer space.
They can be observed by gamma rays, ultra-violet, radio, microwave, x-rays, infrared, and many more similar. Classification of an active galactic nucleus which is based on their observed characteristics has been made and the quasar is the powerful one.
The Mississippi delta is located on the northwest part of the state of Mississippi and is the most southern place on earth and is 7,000 square miles of alluvial flood plains are created by the regular flooding of the Mississippi and Yazoo rivers for thousands of years.
The river deposited sand, and clay, silt along its banks and in adjacent basins, and is shaped of a bird's foot reflecting the dominance of the river over the hydrological and processes. As the river changes its course the natural flow of freshwater and sediments change as well.