Do black holes have anything to do with galaxy formation?

Evidence Central Black Holes Exist Outside the Milky Way December 9, 2009

Is it currently believed that at the center of nearly all galaxies, lies a super massive black hole. The black holes themselves cannot be seen, but the effect that they have on their surrounding galaxy is proof of their existence. The effect that the black holes have, can be witnessed and measured with the M-Sigma relation, which relates the velocity dispersion of the galaxy’s bulge, with the mass of the black hole at it’s center.

By using a Doppler measurement of the surrounding nucleus of a galaxy, scientists found that these galaxies contain strong Keplerian motion. This motion can only be explained by a strong concentration of mass at the center of the galaxy, only explainable by a black hole. For similar galaxies further away, reverberation mapping is used to calculate the mass of the central black hole. Reverberation mapping uses the orbiting gas of the galaxy that circles the event horizon by mapping it’s path using spectral lines. Once mapped, this data can calculate mass and spin of the black hole.

Another indicator of the presence of black holes at a galaxy’s center, is the common sight of massive amounts of energy dispersion from a galaxy’s center. Often massive amounts of matter in the form of a jet of electrons is ejected from the galactic nucleus of a galaxy, being explained by a black holes natural process of matter consumption. This process also emits radio waves which are named as “Hawking Radiation”.