Hidden Black Holes
The August 1 issue of Astrophysical Journal Letters reports a new class of "hidden" Black Holes. These Active Galactic Nuclei give off jets of radiation, but are surrounded by dust so that no light reaches us. Only X-ray spacecraft like Swift and Suzaku were able to detect them. Hidden AGN's could make up 20 percent of the X-ray background.
AGN's have appeared as different types of objects depending upon viewing angle. Their central Black Holes give off twin jets of radiation. When one of the jets points toward us, the galaxy is called a blazar. From a slightly different angle they appear as quasars. Seen edge-on they appear as radio galaxies. Every galaxy yet found contains at its centre a massive Black Hole.
Since every galaxy contains one, it is painfully obvious that Black Holes were there first. The Big Bang created countless billions of singularities in a variety of sizes. They formed the seeds of clusters, galaxies and even smaller structures. Small Black Holes gathered around the big ones, forming haloes of dark mass. Many times these dark mass particles collided with gas in a galaxy's disk. These collisions triggered the formation of stars and solar systems. Our own solar system would not have formed without Black Holes.
In conclusion, Black Holes are not the monsters that people make them out to be. Our life could not have evolved without them. They are close by, even in our planet, so quiet that we barely notice their presence. It is best to say, Black Holes are friends!