| Astrophysics (Index) | About |
The Soltan argument is the reasoning that if distant quasars are powered by black holes (i.e., supermassive black holes, SMBHs) in galaxies, then there must be quiet SMBHs in the ordinary galaxies of today, i.e., those like the Milky Way and other local galaxies. The reasoning is based on a calculation of the expected population statistics of such current black holes based upon that of observed distant quasars: if there were indeed so many SMBHs in the distant past, they must still be around.