On the Origin of Density Cusps in Elliptical Galaxies

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

42

Galaxies: Elliptical And Lenticular, Cd, Galaxies: Kinematics And Dynamics, Galaxies: Nuclei, Galaxies: Structure, Methods: Numerical

Scientific paper

We investigated the dynamical reaction of the central region of galaxies to a falling massive black hole by N-body simulations. As the initial galaxy model, we used an isothermal King model and placed a massive black hole at around the half-mass radius of the galaxy. We found that the central core of the galaxy is destroyed by the heating due to the black hole and that a very weak density cusp (rho ~ r^-alpha, with alpha ~ 0.5) is formed around the black hole. This result is consistent with recent observations of large elliptical galaxies with the Hubble Space Telescope. The velocity of the stars becomes tangentially anisotropic in the inner region, while in the outer region the stars have radially anisotropic velocity dispersion. The radius of the weak cusp region is larger for a larger black hole mass. Our result naturally explains the formation of the weak cusp found in the previous simulations of galaxy merging and implies that the weak cusp observed in large elliptical galaxies may be formed by the heating process by sinking black holes during merging events.

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

On the Origin of Density Cusps in Elliptical Galaxies 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 On the Origin of Density Cusps in Elliptical Galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On the Origin of Density Cusps in Elliptical Galaxies will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1189856

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