The closest quasar is about million light years away. Therefore, we can conclude that there are no quasars in the universe today and the last quasar disappeared about million years ago. Where did the quasars go? No one can say for sure. Given their power source, however, it is most likely that they simply ran out of fuel.
The black holes eventually consumed all the gas and dust in the disk surrounding them, so the quasars ceased to shine.
The Power Source of Quasars Quasars are by far the brightest objects in the universe. However, some of the smaller point-source objects didn't have a match. Astronomers called them "quasi-stellar radio sources," or "quasars," because the signals came from one place, like a star.
However, the name is a misnomer; according to the National Astronomical Observatory of Japan , only about 10 percent of quasars emit strong radio waves. Naming them didn't help determine what these objects were. It took years of study to realize that these distant specks, which seemed to indicate stars, are created by particles accelerated at velocities approaching the speed of light.
Scientists now suspect that the tiny, point-like glimmers are actually signals from galactic nuclei outshining their host galaxies. Quasars live only in galaxies with supermassive black holes — black holes that contain billions of times the mass of the sun. Although light cannot escape from the black hole itself, some signals can break free around its edges.
While some dust and gas fall into the black hole , other particles are accelerated away from it at near the speed of light. The particles stream away from the black hole in jets above and below it, transported by one of the most powerful particle accelerators in the universe. The light emitted isn't actually from the black hole itself but the swirling matter that surrounds it called the accretion disk. The light emitted from the accretion disk is far enough to escape from the pull of the quasar.
A link from wikipedia sufficiently explains this:. Quasars are believed to be powered by accretion of material into supermassive black holes in the nuclei of distant galaxies, making these luminous versions of the general class of objects known as active galaxies. Since light cannot escape the black holes, the escaping energy is actually generated outside the event horizon by gravitational stresses and immense friction on the incoming material.
I am supposing that part of the question, you are asking why quasars are brighter than black holes. That's because of the larger amount of in falling matter into the black hole creates greater friction thus more light. A black hole, in deep space is basically black, and very hard to detect. But if a black hole is surrounded by material, that material will fall towards the black hole and enter into orbit about it.
Black holes don't suck, they gravitate. The material may come from, for example another star, or in the case of the giant black holes at the centre of many galaxies, from the gas, dust and stars that are found in the cores of galaxies.
As objects orbit the black hole they will tend to collide with each other, releasing energy in the form of heat, and causing them to fall to lower orbits. This process tends to cause the gas orbiting a black hole to form into a disk, called an accretion disc.
Pretty soon any larger objects will be broken apart, and the accretion disk will be composed of gas, and as it heats up, plasma. Now as objects fall to lower orbits they speed up. And for a black hole, this speed up is extreme. The gas will be orbiting at speeds that approach the speed of light. The Answer. Show me the Level 1 version of this page.
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