Astronomy and Astrophysics – Astrophysics
Scientific paper
2001-05-23
Astronomy and Astrophysics
Astrophysics
38 pages with 9 embedded Postscript figures. To appear in Merging Processes in Clusters of Galaxies, edited by L. Feretti, I.
Scientific paper
Clusters of galaxies generally form by the gravitational merger of smaller clusters and groups. Major cluster mergers are the most energetic events in the Universe since the Big Bang. Some of the basic physical properties of mergers will be discussed, with an emphasis on simple analytic arguments rather than numerical simulations. Semi-analytic estimates of merger rates are reviewed, and a simple treatment of the kinematics of binary mergers is given. Mergers drive shocks into the intracluster medium, and these shocks heat the gas and should also accelerate nonthermal relativistic particles. X-ray observations of shocks can be used to determine the geometry and kinematics of the merger. Many clusters contain cooling flow cores; the hydrodynamical interactions of these cores with the hotter, less dense gas during mergers are discussed. As a result of particle acceleration in shocks, clusters of galaxies should contain very large populations of relativistic electrons and ions. Electrons with Lorentz factors gamma~300 (energies E = gamma m_e c^2 ~ 150 MeV) are expected to be particularly common. Observations and models for the radio, extreme ultraviolet, hard X-ray, and gamma-ray emission from nonthermal particles accelerated in these mergers are described.
No associations
LandOfFree
The Physics of Cluster Mergers 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 Physics of Cluster Mergers, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Physics of Cluster Mergers will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-97955