Just how many black holes do we have?

William Atkins
Thursday, 06 November 2008 19:03

Science - Space

They estimate that the average star cluster (hundreds of thousands of stars) containing one of these black holes within the Milky Way galaxy would be less than one parsec in size (about 3.26 light-years or about 30 trillion kilometers).

O’Leary and Loeb also contend that these small, compact star systems could have been seen in most standard sky surveys, just not recognized when being analyzed.

However, future analysis of these sky surveys could be performed because these BH-centered star system could be distinguished from globular clusters by several features.

These features include: (1) their compact size (the massive black hole would force them closer together than other groups of stars), (2) their internal velocity (it should be greater than one hundred kilometers per second due to their relationship around the black hole), and (3) their mass-to-light ratio (more mass in these BH clusters due to the central black hole).

According to the New Scientist article “Milky Way might be riddled with black holes” (October 11-17, 2008, page 9), Dr. Loeb stated, “These are fingerprints that are not easy to mimic in any other type of object.”

Further study into these black holes and their star groups could provide us with a look at the early history of our galaxy.

Loeb states, “It could give us a fossil record of the assembly of the galaxy, and also of the black holes in the universe at early cosmic times. It’s just like doing archaeology.” [New Scientist]