Yellow CESAM (hereafter YC) is my personal version of the stellar evolutionary code CESAM originaly written by Pierre Morel from Nice Observatory (France). Compared to the official version CESAM 3.2, I did several developments, improvement and bug corrections (see my Phd Thesis for details). It is easy to use on Linux machine thanks to the GNU compiler g77 (I made a substantial re-writting effort in order to get a code which can be compiled with g77, that was not only a question of compiler option).

A database of evolutionary tracks computed with this code (for various chemical compositions and overshooting amounts) is available on this server here.

I also wrote a web interface to Yellow CESAM, the page about this project is available on this server here. This kind of web interface can be adapted to any code, I am currently writting such an interface for various programs like isochrones maker, population synthesis program, ... for the BASTI database.

Finally, for people who are bored by stellar structure and evolution calculations: relax and read my "Funny Physics" page, and enjoy the short movies! It is not necessary to be fluent in french language to understand the purpose of each experiment.

To install YC, you have to follow these steps:

• First of all, download the source code archive here: ycesam.tar.gz
• gunzip and untar this files:
  
  tar xvfz ycesam.tar.gz
• go in the ycesam directory and type:
  
  make

If the GNU FORTRAN compiler g77 (I did not test new g95 compiler yet) is installed on your machine, you should not have any problem during this operation.
You should get the following library: lib_YCesam.a
• Download the main program source: main_ycesam_std.f and compile YC with a command line similar to:
  g77 -O6 -fno-automatic -fugly-assumed -malign-double -o my_cesam_executable main_ycesam_std.f lib_YCesam.a -lpgplot -lX11

Notices:
• If you don't have PGPLOT library or X11 library on your machine: change dess_ol_dig01 into no_des_3 (that will remove plots during CESAM computations) in main_ycesam_std.f source.
• TEST your executable:
  ./my_cesam_executable
  Your should get something like this:
  

  

• Opacity tables for a solar mixture (GN93):
  • download the following archive: opa_OPAL96_YL.tar.gz. This packages has been originally written by Yveline Lebreton from Paris-Meudon Observatory, I just modified some stuffs for the adaptation to Yellow CESAM.
  • gunzip and untar the file:
    tar xvfz opa_OPAL96_YL.tar.gz
  • go in the created opa_OPAL96_YL directory and compile the FORTRAN program fmttobin.f:
    
    make
    
    with g77 this operation should not cause any problem.
  • run the program that transform ASCII opacity tables into binary one:
    
    ./fmttobin
    
    answer in this spirit:

    

    gn93o_s9 is the ASCII table. The program gives you a binary file (named here "OPAL_96.dat") which will be used by Yellow CESAM for its calculations.
• Opacity tables for He burning core:
  • download the following archive: opacity_He_burning_core.tar.gz
  • gunzip and untar the file:
    tar xvfz opacity_He_burning_core.tar.gz
  • go in one of the created directories, for instance:
    opacity_He_burning_core/data_SMC/, and type:
    
    make
    the code should be compiled.
  • run the opacity table maker program:
    
    ./fmaker4.1
    answer like this:

    

    In this example, "opa_HeB_SMC.dat" is the opacity table which will be used as an input file for YC.
  • do the same thing in other subdirectories:
    • opacity_He_burning_core/data_LMC/
    • opacity_He_burning_core/data_MW/
• Now you should have four different opacity tables files, called e.g.:
  • OPAL_96.dat
  • opa_HeB_SMC.dat
  • opa_HeB_LMC.dat
  • opa_HeB_MW.dat

• download the archive file: nucreac_rate_tables.tar.gz
• gunzip and untar this archive following the standard procedure
• go in the "nucreac_rate_tables/" directory and compile the programs: ./make, you should get two executables:
  • tab_bin_CF
  • tab_bin_NACRE
• If you want to use Caughlan and Fowler nuclear reaction rates, run tab_bin_CF, you have just to specify the ouput file name. If you prefer NACRE rates run tab_bin_NACRE. In both cases you will be prompted for the name of the binary output file generated by tab_bin_CF or tab_bin_NACRE.

• As YC is based on a Newton-Raphson method, one needs a first guess. One will find a stellar structure for a 5 solar masses homogeneous model in this ASCII files : m050.dat
• make a working directory, for instance: myworkingdir
• copy m050.dat and this input file: sample_intput_file_YC.don3 in myworkingdir.
  For a commented version of this input file see here (comments are in blue).
• Edit sample_intput_file_YC.don3 and adapt the paths and names corresponding to the opacity table files and the nuclear reaction rates file.
• The first run
  • the aim is to build an homogeneous model at age 0.00 Myears
  • run YC:
    MYPATH/my_executable
  • question 1: choose 2 (to make a ZAMS model)
  • question "le modele initial de ZAMS est-il donne en binaire ? o/n": choose "n" ("m050.dat" is an ASCII file)
  • question "entrer le nom du fichier ASCII du modele pris pour modele initial": answer "m050.dat"
  • question:
    "entrer l'identificateur du modele
    exemple: soleil_evolue"
    give the name of your input file, in our example: sample_intput_file_YC (without ".don3").
  • The program should run now ... and when the convergence is reached, you should get this message:

    

    Answer "o" (yes) or "n" (no) if you want (or not) plots during YC run. Execution ends with:

    

• Next runs
  • Among output files a "*.hom" file ("*.rep" are equivalent) has been produced. This is a binary file that has to be used to begin the calculation (choice 1 for the first question asked by YC)
  • If you have chosen the plot option (that requires compilation with PGPLOT ans X11 library), you should get plot as beautiful as this:

    

    Chemical composition, pressure, temperature, convective zones extension ... are displayed.

Yellow CESAM produces various output files, the most important are:

• sample_intput_file_YC.struc: internal structure of the last computed model during a given stellar evolution (explanations are in the file itself).
• sample_intput_file_YC.HR: several quantities (central temperature/pressure, effective temperature, chemical composition (center and surface), ... as a function of time (see ycesam.f subroutine or contact me for more detailed information and/or for FORTRAN program which read this kind of file).

I also partially rewrote CESAM 4.4 in order to get a code which can compiled with GNU g77 compiler (exotic compilation options are not enough). Beside this I did some personal modifications but my version remains quite close to the official version (unfortunately I lost the version with only modifications related to compilation problems). Sources can be downloaded here:

• the code itself (with documentation (in french) and various programs): ycesam4.4.tar.gz
• the "standard" main program: exe_STD.f, it has to be compiled with the following include file: modele.common
• finally, a sample input file is provided: sample_input.don4

This code (version with minimum modifications) has been already used by Reza Samadi (the guy who asked me for modifications), Juan-Carlos Suarez (former PhD Student in Meudon), Anwesh Mazumdar (former Post-Doc in Meudon Observatory) and Eric Michel.

Web pages related to CESAM:

• The web-interface to CESAM I wrote a few years ago: here.
• Pierre Morel's web page: http://www.obs-nice.fr/morel/fichier_perso.html
• "Official" CESAM home page: http://www.obs-nice.fr/cesam

Other available codes related to stellar physics:

• The STARS code is a sofware similar to CESAM, it was originally developed in the 1970's by Peter Eggleton, the source code is downloadable after resquest; outputs (stellar evolution tracks) are also available for massive stars (masses up to 200 solar masses). See the STARS home page.
• TYCHO is a general, one dimensional (spherically symmetric) stellar evolution code, designed for hydrostatic and hydrodynamic stages. See the TYCHO web page. The code is available here.
• EZ: a version of the STARS code already mentioned, rewritten in Fortran90 by Bill Paxton following modern programming practices. The code is available at the Bill Paxton's web page, EZ has a web-interface (written by Rich Townsend at the University of Delaware) here. Now EZ has been replaced by MESA: http://mesa.sourceforge.net. See also the interesting TIOGA program
.
• FreeEOS: an Equation Of State (EOS) for stellar interiors by Alan W. Irwin: http://freeeos.sourceforge.net/
• The Cloudy home page: http://www.nublado.org
• TMAP (the Tübingen-NLTE-Model-Atmosphere-Package): http://astro.uni-tuebingen.de/groups/stellar/tmap.

			Daniel Cordier, Laboratoire GSMA - Université de Reims,