The Black Hole Mass Density from Velocity Dispersions

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Scientific paper

Using a basic assumption that the bulge velocity dispersion of a galaxy can be used to predict the mass of its supermassive black hole, it is possible to estimate the mass density of black holes in the universe. Constructing the number density as a function of galaxy velocity dispersion from published data, an expression for the number density of black holes as a function of mass can be constructed. By taking a Schechter-type luminosity function for a given galaxy type, and applying an appropriate bulge-to-total galaxy magnitude correction, the number density as a function of bulge luminosity can be obtained. This function may then be combined with a Faber-Jackson power law relating velocity dispersion and luminosity to obtain a velocity dispersion function for each galaxy type. By coupling this dispersion function with a relationship between the mass of the black hole and the velocity dispersion of its host galaxy, it is possible to produce an expression for the number density of black holes as a function of black hole mass for each galaxy type, which is of a similar form to a Schechter function. By integrating this function over all black hole mass, an estimate of the mass density of black holes for a given galaxy type may be obtained. Summing over all galaxy types, the cumulative mass density of black holes is found to be 6 ṡ 105 solar masses per cubic megaparsec for an h=1 universe. The authors acknowledge support from NASA/Space Telescope Science Institute.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

The Black Hole Mass Density from Velocity Dispersions does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Black Hole Mass Density from Velocity Dispersions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Black Hole Mass Density from Velocity Dispersions will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1230540

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.