Particle-Mesh code for cosmological simulations

Particle-Mesh (PM) codes are still very useful tools for testing predictions of cosmological models in cases when extra high resolution is not very important. We release for public use a cosmological PM Nbody code. The code is very fast and simple. We provide a complete package of routines needed to set initial conditions, to run the code, and to analyze the results. The package allows you to simulate models with numerous combinations of parameters: open/flat/closed background, with or without the cosmological constant, different values of the Hubble constant, with or without hot neutrinos, tilted or non-tilted initial spectra, different amount of baryons. Routines are included to measure the power spectrum and the density distribution function in your simulations, and a bound-density-maxima code for halo finding. We also provide results of test runs. A simulation with 256 mesh and 128 particles can be done in a couple of days on a typical workstation (about 70Mb of memory is needed). To run simulations with 800 mesh and 256 particles one needs a computer with 1Gb memory and 1Gb disk space. The code has been successfully tested on an HP workstation and on a Sun workstation running Solaris, but we expect it should work on other systems. The package can be downloaded from http://astro.nmsu.edu/∼aklypin/PM/PMcode.tar.gz A PostScript version of this manual can be obtained from http://astro.nmsu.edu/∼aklypin/PM/PMcode.ps.gz We provide this tool as a service to the astronomical community, but we cannot guarantee results.