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treesfr - treecode with sticky particle ISM model and star formation




treesfr is the Hernquist fortran version of the Barnes and Hut treecode, with an added sticky particle ISM model and star formation. Details on the N-body code can be found in treesfr.f, though is largely the same as that described in the original treecode.f (see treecode2(1NEMO) ), whereas all details on the ISM/SFR modeling can be found in treeism.f.

Computational units are such that the gravitational constant G=1.


Two input (ASCII) files must be present at runtime:

A parameter file with the name TREEPAR contains, line by line, the input parameters for this run (the names of the variables in the first column are actually the names of the variables in the program):

 headline      Identification string for the run (max 50 char)
 nsteps        Number of timesteps
 noutbod           frequency of TREEBO, TREECONT, and TREEISM writes
 noutlog       Output logfile data once every nsteps/noutlog steps (TREELOG)
 dtime         The timestep
 tol             Error tolerance; 0.0=exact
 seps          Potential softening parameter for stellar particles
 geps          Potential softening parameter for cloud particles
 usequad       Option to include quadrupole terms (.TRUE./.FALSE.)
 minit          initial ISM cloud mass
 r0               initial ISM cloud size
 tau0           coefficient for cloud lifetime calculation
 sfrcoeff        coefficient for SFR law
 rcrit          radius for determining ambient ISM density
 ismrate          rate at which ISM properties are calculated
 iseed           random number seed

In addition there must be a file TREEBI, containing the input bodies. This is a slightly modified version of the format used in treecode2, where an array of nbody logicals signifies if that particle is gas (T) or stellar (F).

Output files created are the regular output from treecode2 TREEBOA, which contains all the requested snapshots in ascii atos(1NEMO) format, TREELOG, which contains a log of the run and TREEBO, which contains a binary (machine dependable) dump of the last snapshot. In addition, ISM/SPH specific files are TREEISM, TREEILOG and TREECONT. Note that these three output files must not be present when the program is to be run.

To avoid excessive overhead, noutlog should be larger than 1, typically ~ 10, depending on total number of steps though.


The accompanying Makefile has ready made targets to compile treecode2 on the Cray, Sun and Vax, by appropiately defining the OS macro in the Makefile, as well as running benchmarks within NEMO’s environment. See Makefile for details.


Chris Mihos


~/usr/cmihos/treesfr/ ~/usr/lars/treecode2/     ~/src/nbody/evolve/treecode2/    official NEMO version

TREEBI      input bodies
TREEPAR         input parameters
TREEBO           output bodies
TREELOG        output logfile
TREEBOA          output bodies, last snapshot??
TREEISM         output ISM cloud properties
TREEILOG       output logfile of cloud interactions
TREECONT         output continuation file (same format as TREEBI)

See Alsohackcode1(1NEMO), treecode(1NEMO), newton0(1NEMO), nbody0(1NEMO)
15-jun-92    Put formal version into usr/cmihos/treesfr    PJT

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