Stellar Receipes

Here are sample datafiles and methods for construction of just about any model you might want.

Multi-step procedures

To acheive the necessary models for a certain evolutionary run, it is sometimes necessary to take several steps using different data files.

Normal evolution

Probably the most used datafile. This is for a model with X=0.70, Z=0.02. There is no mass loss, and convective overshooting is turned off.

 199  40  40  11  11   2   1   1   1   1   1
   1   2   1   1   0   0   0   0    
 100   1   1   1   2  50
 1.0E-06 1.0E-02 1.0E-07 1.0E+00 5.0D-00
  5  5  0  3  1 30  0  0  0 99
  1  2  4  5  3  9 10 11  8  7  6  0  0  0  0
  6  7  8  9 10  4  2  1  3  5  0  0  0  0  0
  4  5  6  7  8  2  3  1  2  3  1  0  0  0  0
  0  0  0  0  0  0  0  0  0  0
  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  
  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
  1  2  3  4  8  9 10 11 12 17 18 19 20 21 33
  3 17  9 24 30 25 26 27 28  2  4  0  0  0  0
  8  9 10 11 12 13 14 15 16 20 22  0  0  0  0
 0.80 1.20 9.99 0.00 0.05 0.50 0.15 0.02 0.45 1.0E-04 1.0E+15 3.0E+19
 2.00E-02 2.000 0.700 0.173 0.053 0.482 0.099 0.038 0.083 0.072
 1.00E+06 0.00E-00 0.00E-00 0.00E-00 0.00E-00 0.10E-00 0.01E+00 
 1.00E+03 0.00E-00 0.00E-00 0.00E+00 1.00E+00 0.00E-00 0.00E+00

AGB evolution

A data file for AGB evolution, with X=0.70, Z=0.02. A constant mass loss rate is included.

 199  40  20  11  11   3   1   1   1   1   1
   1   2   1   1   0   0   0   0    
 100   1   1   1   2 100
 1.0E-06 1.0E-02 1.0E-07 1.0E+00 5.0D-00
  5  5  0  3  1 30  0  0  0 99
  1  2  4  5  3  9 10 11  8  7  6  0  0  0  0
  6  7  8  9 10  4  2  1  3  5  0  0  0  0  0
  4  5  6  7  8  2  3  1  2  3  1  0  0  0  0
  0  0  0  0  0  0  0  0  0  0
  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  
  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
  1  2  3  4  8  9 10 11 12 17 18 19 20 21 24
  3 17  9 24 30 25 26 27 28  2  4  0  0  0  0
  8  9 10 11 12 13 14 15 16 20 22  0  0  0  0
 0.80 1.20 2.05 2.00 0.05 0.01 0.30 0.50 0.45 1.0E-04 1.0E+15 3.0E+19
 2.00E-02 2.000 0.700 0.173 0.053 0.482 0.099 0.038 0.083 0.072
 1.00E+06 0.00E-00 0.00E-13 1.00E-09 0.00E-00 0.10E-00 0.01E+00
 5.00E+02 0.00E-00 0.00E-01 0.00E+00 1.00E+00 0.00E-11 0.00E+03

White dwarf evolution

This is for a white dwarf with X=0.76, Z=0.02. The evolution includes a constant mass loss rate.

 199  40  10  11  11   0   1   1   1   1   1
   1   2   1   1   0   0   0   0    
 100   1   1   1   2 100
 1.0E-06 1.0E-02 1.0E-07 1.0E+00 1.0D+01
  5  5  0  3  1 30  0  0  0 99
  1  2  8  4  5  3  9 10 11  7  6  0  0  0  0
  6  7  8  9 10  4  2  1  3  5  0  0  0  0  0
  4  5  6  7  8  2  3  1  2  3  1  0  0  0  0
  0  0  0  0  0  0  0  0  0  0
  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  
  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0 
  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0 
  2  3  4  8  9 10 11 12 13 17 18 19 20 21 24 
  3 17  9 24 30 25 26 27 28  2  4  0  0  0  0 
  8  9 10 11 12 13 14 15 16 20 22  0  0  0  0 
 0.80 1.20 2.05 2.00 0.05 0.01 0.60 0.35 0.45 1.0E-04 1.0E+15 3.0E+19 
 2.00E-02 2.000 0.760 0.173 0.053 0.482 0.099 0.038 0.083 0.072 
 1.00E+06 0.00E-00 0.00E-09-1.00E-14 0.00E-00 0.10E-00 0.01E+00  
 5.00E+02 0.00E-00 0.00E-01 0.00E+00 1.00E+00 0.00E-03 1.00E+04	   

Multi-step Procedures

Pre-Main Sequence Evolution

Or how to make a gas cloud. The best way of doing this is to start from a star of low mass, say a 0.3 solar mass main sequence model. This can then be evolved back up it pre-MS track by using the parameters EC and ECT. The following data block will do the necessary evolution:

 199  40  10  10  10   2   1   0   0   0   0
   1   2   1   1   0   0   0   0    
 100   1   1   1   2  50
 1.0E-06 1.0E-02 1.0E-07 1.0E+00 1.0D+00
  5  0  0  3  1 30  0  0  0 99
  1  2  4  8  7  6  0  0  0  0  0  0  0  0  0  
  4  2  1  3  5  0  0  0  0  0  0  0  0  0  0 
  2  3  1  2  3  1  0  0  0  0  0  0  0  0  0
  0  0  0  0  0  0  0  0  0  0
  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  
  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
  2  3  4  7  8  9 10 11 18 17 27 23 24 25 26
  1  4  8  9 10 11 12 13 14 15 16 18 19 20 21
  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
 0.80 1.20 2.05 2.00 0.05 0.01 0.60 0.35 0.45 1.0E-04 1.0E+15 3.0E+19  
 2.00E-02 2.000 0.700 0.173 0.053 0.482 0.099 0.038 0.083 0.072
 1.00E+06 0.00E-00 0.00E-00 0.00E-03 0.00E-00 0.10E-00 0.01E+00  
 1.00E+03 0.00E-00 0.00E-01 0.00E+00 1.00E+00 1.00E-06 0.00E+00
I also recommend giving the model a small EC in modin.

Once the star has been taken back up the track far enough, the data file can be ammended so that mass can be added. The value of ECT should be set to zero, while RMG should be made non-zero (say 10-7). Once sufficient mass has been achieved, set EC to zero, and run the normal evolution data file.

Composition Changes

This should be done from a pre-main sequence model, as may be created by the above method. With the created model, a data file with NCH=3 and ZS set to the desired metallicity should be run. Also, it should be noted that file with values for the metallicity that you require is needed to replace phys02.dat.

Post-He flash models

This section will hopefully soon be redundant, as I am working on making the code evolve through the He-flash on it's own. Until that works, the following route needs to be used:

The first step is to get a star that is burning core helium non-degeneratly. Take a 3 solar mass star and evolve it as normal using the following data file:

 199  40  40  11  11   2   1   1   1   0   1
   1   2   1   1   0   0   0
  50   1   1   1   2  10
 1.0E-06 1.0E-02 1.0E-07 1.0E+00 1.0E+00
  5  5  0  3  1 30  0  0  0 99
  1  2  4  5  3  9 10 11  8  7  6  0  0  0  0
  6  7  8  9 10  4  2  1  3  5  0  0  0  0  0
  4  5  6  7  8  2  3  1  2  3  1  0  0  0  0
  0  0  0  0  0  0  0  0  0  0
  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
  1  2  3  4  8  9 10 11 12 17 18 19 20 21 33
  3 17  9 24 30 25 26 27 28  2  4  0  0  0  0
  8  9 10 11 12 13 14 15 16 20 22  0  0  0  0
 0.80 1.20 9.99 0.00 0.05 0.50 0.15 0.02 0.45 1.0E-04 1.0E+15 3.0E+19
 2.00E-02 2.000 0.716 0.173 0.053 0.482 0.099 0.038 0.083 0.072
 1.00E+06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 1.00E-01 1.00E-02
 1.00E+03 0.00E+00 0.00E+00 0.00E+00 1.00E+00 0.00E+00 0.00E+00

This has IY=0 so that helium is burned but not consumed. Allow the model to evolve up to the point where helium has just ignited under non-degenerate conditions. Take this output model, and strip it of mass using the following:

 199  40  40  11  11   2   1   1   0   0   1
   1   2   1   1   0   0   0
  50   1   1   1   2  10
 1.0E-06 1.0E-02 1.0E-07 1.0E+00 1.0E+00
  5  5  0  3  1 30  0  0  0 99
  1  2  4  5  3  9 10 11  8  7  6  0  0  0  0
  6  7  8  9 10  4  2  1  3  5  0  0  0  0  0
  4  5  6  7  8  2  3  1  2  3  1  0  0  0  0
  0  0  0  0  0  0  0  0  0  0
  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
  1  2  3  4  8  9 10 11 12 17 18 19 20 21 33
  3 17  9 24 30 25 26 27 28  2  4  0  0  0  0
  8  9 10 11 12 13 14 15 16 20 22  0  0  0  0
 1.00 1.00 9.99 0.00 0.05 0.50 0.15 0.02 0.45 1.0E-04 1.0E+15 3.0E+19
 2.00E-02 2.000 0.716 0.173 0.053 0.482 0.099 0.038 0.083 0.072
 1.00E+06 0.00E+00 0.00E+00-1.00E-06 0.00E+00 1.00E-01 1.00E-02
 1.00E+03 0.00E+00 0.00E+00 0.00E+00 1.00E+00 0.00E+00 0.00E+00

Here we have IX=0 as well so that the core doesn't grow in mass. The mass loss rate must be small or problems will occur. I also found it necessary to alter the initial timestep by a factor of about 1000. Once the star is reduced to the desired total mass, we need to fix the core mass to the desired value. To increase the core mass (which is usually what is required) set IX=1 and let some hydrogen burn.


E-mail: stars@ast.cam.ac.uk
Last modified: Thu Oct 9 15:00:51 2003
by R. Stancliffe