Astronomy and Astrophysics – Astrophysics
Scientific paper
2007-01-12
Astronomy and Astrophysics
Astrophysics
6 pages, 4 figures. v2: implications for semi-analytical model added. Accepted by ApJ
Scientific paper
In a hierarchical picture of galaxy formation virialization continually transforms gravitational potential energy into kinetic energies of the baryonic and dark matter. For the gaseous component the kinetic, turbulent energy is transformed eventually into internal thermal energy through shocks and viscous dissipation. Traditionally this virialization and shock heating has been assumed to occur instantaneously allowing an estimate of the gas temperature to be derived from the the virial temperature defined from the embedding dark matter halo velocity dispersion. As the mass grows the virial temperature of a halo grows. Mass accretion hence can be translated into a heating term. We derive this heating rate from the extended Press Schechter formalism and demonstrate its usefulness in semi-analytical models of galaxy formation. Our method explicitly conserves energy unlike the previous impulsive heating assumptions. Our formalism can trivially be applied in all current semi-analytical models as the heating term can be computed directly from the underlying merger trees. Our analytic results for the first cooling halos and the transition from cold to hot accretion are in agreement with numerical simulations.
Abel Tom
Wang Peng
No associations
LandOfFree
Dynamical Treatment of Virialization Heating in Galaxy Formation 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 Dynamical Treatment of Virialization Heating in Galaxy Formation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dynamical Treatment of Virialization Heating in Galaxy Formation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-217742