Two Body Relaxation in CDM simulations |
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Maps of a cluster's density (top) and relaxation since virialisation (bottom) out to r_200 (N_200 = 650'000). The logarithmic scale for the degree of relaxation goes form 0.01 (black) to 100 (white). (Same as Figure 9 in astro-ph/0304549 but higher resolution) size: 576k format: jpeg |
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Same for a galaxy at lower resolution (N_200 = 250'000). size: 434k format: jpeg |
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The movie shows N=10'000 equal mass particles orbiting in their own potential. They are colored according to the local density, which is constant in time everywhere, since the particles follow some stationary solution of the Boltzmann equation (a Hernquist model in this case). The 10'000 green particles are massless tracers. They were placed following the same distributions in real and velocity space as the massive ones, but are restricted to a fixed orbital plane, which is seen edge on. In the mean field limit (N to infinity) the tracers would stay in this plane forever. Encounters with the massive particles make them leave this plane and their velocity components perpendicular to the plane (or their energy dispersion) gives the degree of relaxation show the bottom of each frame. format: mpeg, size: 27M ! |
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The movie shows a halo with 1'000 particles falling into a ten time more massive halo with 10'000 particles (not shown) in the centre of the box. As above we have planes of massless tracer particles to measure the degree of relaxation for the satellite and the main halo. The green points are the 1'000 tracers of the infalling satellite, the tracers of the main halo are not shown. format: mpeg, size: 6.5M High resolution version, size: 31M ! |
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| Last modified: Fri Sep 26 2003 by diemand@physik.unizh.ch |  |