scientific evidence for black holes (Score 1)

Black holes are known to exist in our Galaxy, M31, and NGC 4258. The evidence for black holes is usually provided by ruling out all the other possibilities. An excellent example paper (for M31) is here: http://xxx.lanl.gov/abs/astro-ph/0509839 Actually the slashdot.org crowd could look here for the most relevant science papers on astrophysics: http://xxx.lanl.gov/list/astro-ph/new The people working on this ESO project are all brilliant astronomers.