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Simon Portegies Zwart (Univ. Amsterdam with 2 GRAPE-6 boards)
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Simulation of star cluster (6144 stars) done with GRAPE-4; watch for ejection of high-velocity star on left side about 1/3 of the way through the animation
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Star cluster Palomar-5 (from the SDSS)
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Simulation of star cluster(6500 stars) orbiting the galactic center for 0.75 Myr. Initial density profile is a King model. Cluster starts at 4pc from galactic center but spirals in. 1 orbit = 10 5 yrs. Notice the star colors in the tidal tails; these researchers include stellar evolution with dynamics!
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Accretion of ~200 satellite galaxies by the MW; simulation by James Bullock and Kathryn Johnson; context: Cold Dark Matter is hierarchical when it comes to structure formation
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Real Host and Satellite Galaxies from the SDSS!
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B-band surface brightness expected for Milky Way- type galaxy after accretion of satellites; Projection is 300 kpc X 300 kpc
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Galaxy collisions are important for establishment of morphology. Disks are extremely FRAGILE. simulation by Volker Springel at MPIA Note: this is a gravity + gas simulation; the spirals are in the gas not the dark matter
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Cold Dark Matter (WIMPs) Warm Dark Matter (mostly CDM but with some neutrinos as well) Hot Dark Matter (neutrinos) Simulations by Ben Moore (Univ. of Zurich)
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One of these is the actual Coma cluster; one is a dark matter simulation of a cluster by Ben Moore
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CDM generically gives “filamentary” structure in the universe (another of Ben Moore’s simulations)
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Galaxies are observed to be “clustered” in space (not random)
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Which one is the 2dFGRS? Which are taken from CDM simulations?
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CDM generically predicts mildly- flattened halos ( ~ 0.3) with a lot of dark matter substructure Spherically-averaged density profile is NOT isothermal (“Navarro, Frenk & White”) Milky Way sized halo from one of Ben Moore’s simulations
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Changing the cosmological parameters (but not the type of dark matter) radically changes the history of structure formation
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“State of the Art” in 1996 (Volker Springel et al.) 256 3 particles, m p =2.3x10 9 M sun to 6.9x10 9 M sun, 240 x 240 x 240 Mpc box “Adaptive” P 3 M code
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Millennium Run Simulation (Volker Springel et al. 2005) Largest CDM simulation ever run (> 10 billion particles) m p = 8.6 x 10 8 M sun 500 Mpc x 500 Mpc x 500 Mpc box TreePM Force resolution of 5 kpc More than 20 million galaxies Much of the data are publicly-available (big part of Ingo’s thesis work)
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Zoom in to a cluster at z=0
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Growth of structure from z=20 to z=0 in “comoving” coordinates
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