NONLINEAR THERMAL INSTABILITY IN THREE DIMENSIONS

Setup:
  • Initial conditions: uniform gas distribution in a box; zero velocities
  • Periodic boundary conditions
  • Isobaric density perturbations (3D PSD power index -3)
  • Equilibrium radiative cooling function
  • Constant volumetric heating rate proportional to the gas density
  • Handouts:

  • Plate 1 [GIF | PS]
  • Plate 2 [GIF | PS]
  • Plate 3 [JPG | PS]
  • Plate 4 [JPG | PS]
  • Supersonic quasi-isothermal turbulence induced by thermal instability

    Alexei Kritsuk & Michael Norman

    Numerics:
  • Unigrid 128^3, 256^3 + AMR
  • Zeus/PPM_DE hydro solvers
  • Explicit split scheme for the source terms
  • Code "enzo"
  • Parameters:

  • Box size
  • Initial gas temperature & density
  • Heating rate
  • Gas metallicity
  • Most of the movies on this page are in MPEG-1 format. Moyager by Gromada.com is our suggested Windows player (freeware; supports FLIC, MPEG, HAV, JPEG, PNG...). We recommend a frame rate of 10 fps. For better quality playback under UNIX/Linux we suggest to use mpeg_play with these options: -dither color -framerate 10
    Paper I. Thermal Instability-induced Interstellar Turbulence

    5 pc Box (initial temperature 2 mln K)
    Heating Density Field Density PDF Column Density PDF Phase Diagrams 1D Power Spectra Global Diagnostics Structure
    0.1

    Paper II. Interstellar Phase Transitions Stimulated by Time-dependent Heating A news article in Science magazine by Robert Irion A news article in Scientific American by Sarah Graham

    20 pc Box (initialized with two-phase low density medium)
    Heating Density Field Density PDF Phase Diagrams 1D Power Spectra Global Diagnostics
    0.1

    5 pc Box (') initialized as above, but intermediate density case
    Heating Density Field Density PDF Phase Diagrams 1D Power Spectra Global Diagnostics
    0.02

    (') -- Physical quantities should be rescaled to fit the specified box size, see Paper II
    Paper III. Scaling Relations for Turbulence in Multiphase Interstellar Medium

    5 pc Box (initial temperature 2 mln K)
    Heating Density Field Density PDF Temperature PDF Phase Diagrams 1D Power Spectra Global Diagnostics Structure
    0.02

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    Number of external visits since Dec 19 2001
    Last modified:
    Comments to: akritsuk@ucsd.edu
    Center for Astrophysics and Space Sciences Laboratory for Computational Astrophysics