Patrick Motl's Homepage

Mailing Address Louisiana State University Department of Physics and Astronomy 202 Nicholson Hall Baton Rouge, LA 70803-4001 Office 264 Nicholson Hall Work Phone Number 225.578.8277 Fax Number 225.578.5855 email motl at lsu.edu department home page Highland Road Park Observatory relativity group Observation for the day: eat more oatmeal... better yet, eat only oatmeal.

A four minute clip for the 207th AAS meeting visualization competition, quicktime (mpeg-4 encoding) (268 MB) alternate encodings that may work better if you aren't using quicktime 7

• My CV

  html, pdf

• Research Links

  • Flow-er code tests

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  • Numerical Cosmology

    • The Simulated Cluster Archive at the Laboratory for Computational Astrophysics

    • Movies from my galaxy cluster simulations using enzo

    • Catalogs of galaxy clusters including systems down to a virial mass of 1 x 10¹⁴ M_solar
      • Clusters evolved assuming adiabatic physics only
      • The catalog in the limit of cooling only
      • Clusters evolved with cooling and star formation
      • And finally, the most complete sample to date including cooling, star formation and a moderate amount of thermal feedback from prompt supernovae.

    • Galaxy cluster sample organized by refined regions

    • Select clusters ran with cooling only compared to their adiabatic counterparts
      • Cluster 0
      • Cluster 1
      • Cluster 1 ran at various resolutions

    • Select clusters ran with star formation
      • Cluster 1
      • Cluster 44 run a variety of ways to test the algorithm
        • Varying the efficiency of star formation
        • Varying the amount of thermal feedack
        • Varying the minimum mass threshold to form stars
        • Varying the overdensity threshold
        • Introduce ad hoc truncation of star formation at a specified redshift
        • At 7 to 10 refinement levels

    • Timelines for some of the more massive clusters in the sample, including kinetic SZE images. Star formation with feedback only.

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  • Numeical Astrophysics

    • Simulations of a semi-detached binary with q = 0.4
      • Baseline evolution of the q = 0.4 binary
        • Completed evoltion at a resolution of 162 x 98 x 256 (Model Q0.4A)
        • Higher resolution evolution with 354 x 258 x 512 cells
      • Driven evolutions of the q = 0.4 binary, impose angular momentum loss at the specified percentage rates per orbit begining at 7.7 orbits and continuing throughout the remainder of the simulation
        • 2e-4 driving
        • 1e-3 driving (Model Q0.4B)
        • 2e-3 driving (Model Q0.4C)
        • 5e-3 driving (Model Q0.4D)

    • Simulations of a symmetrical contact binary run in a few different ways
      • The original run through 23 orbits. This run did not have the center of mass correction turned on and the stars ran into the edge of the grid.
      • The same binary rerun with center of mass correction. It has gone through 131 orbits thus far.
      • And another version of the same initial conditions, this time evolved without the center of mass correction but embedded in a larger grid. It has run 12 orbits thus far.

    • Simulations of a single = 3/2 polytrope evolved with a modified entropy profile, aka gamma not equal to gamma if that clarifies things
      • alpha = 0.0, the benchmark, unmodified evolution
      • alpha = - 0.25 a convectively unstable polytrope
      • alpha = - 0.5 a polytrope with an even stronger superadiabatic entropy gradient, this is the evolution that I have run the furthest
      • alpha = 0.25 a polytrope with the desired main sequence type mass - radius relation
      • alpha = 0.5 and finally, a polytrope with an even stronger increase in entropy towards the stellar surface. For this value of alpha though, the star is evolved with a polytropic exponent that is less than 4/3. As you will see, this is dynamically unstable, the entire star collapses down to a cell in approximately a free-fall time.

    • Older collection of binary simulations and movies

    • A set of SCF simulations to test the point mass approximation for semi-detached systems with varying compressibility
      • summary plots
      • n = 0.1 (nearly incompressible)
      • n = 0.5
      • n = 1
      • n = 1.5
      • n = 2
      • n = 3 (very centrally condensed)

    • Images and movies from some other test problems

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  • Data that I assembled from the Chandra public archive of rascally cool core clusters, now rather dated.

• Performance results for the LSU hydrodynamics code
  • On Tungsten at NCSA
  • The following are older results from our code on three machines that we used to use heavily. The machines have since been retired
    • caSPer, the SP-3 at LSU
    • Blue Horizon, the SP-3 at SDSC
    • Golden, the Cray T3E at SDSC
    • a comaprison of performance on all three platforms

• Presentations

  by year from 1999 to the present

• Proposals

  by year from 2002 to the present

• Some pictures, mostly of Sophia